Environmental, Drainage, and Landscape Amendments: proposed draft language — original pdf

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CHAPTER 25-2. ZONING. ARTICLE 9. LANDSCAPING § 25-2-981 - APPLICABILITY; EXCEPTIONS. (A) Except as provided in Subsection (B), this article applies in the city's zoning jurisdiction. (B) Division 2 (Requirements for a Site Plan) and Division 3 (Additional Site Plan Requirements in Hill Country Roadway Corridors) do not apply to: (1) property zoned central business district or downtown mixed use district, except for (Functional Green); a lot containing one single-family residence; a lot containing one duplex residence, unless the residence exceeds 4,000 square feet of gross floor (2) (3) area or has more than six bedrooms; (4) (5) (6) (7) (8) a two-family residential use; a secondary apartment special use; substantial restoration of a building within one year after the building is damaged; restoration of a building designated as a historic landmark; or interior or facade remodeling, if the front and side exterior walls of the building remain in the same location. (C) Developed property, or property with an approved site plan, that is affected by right-of-way condemnation may be developed without compliance with this article, as provided by this subsection. (1) After condemnation, improvements shown on the remainder of an approved site plan may be constructed, and only the landscaping on the remainder of the approved site plan is required. Improvements on developed properties that are lost through condemnation may be replaced. Only the area within the limits of construction for the replaced improvements must comply with this article, except an owner is not required to provide more landscaping than was in existence before the condemnation. (2) Division 2. Requirements for a Site Plan. § 25-2-1007 PARKING LOTS. (A) For each 12 parking spaces in a parking lot that is in a landscape yard, a minimum of 90 square feet of landscaped area are required within the parking lot. For each 12 parking spaces in a parking lot that is not in a landscape yard, a minimum of 60 square feet of landscaped area are required within the parking lot. (C) A parking lot must have end islands landscaped with trees in accordance with the Environmental Criteria Manual. (D) Except as provided in Subsection (E), a parking space may not be located more than 50 feet from a landscaped area, or more than 50 feet from a tree. In a parking lot that has more than three distinct modules for the parking of vehicles: (1) a landscaped median at least 10 feet wide and at least the length of the parking module is required for every second parking module for the parking of vehicles; a tree must be located within 25 feet of each parking space adjacent to a median; and end islands with trees are required. (2) (3) (F) A landscaped area that is required by this section: (1) may consist of non-contiguous portions, and may be in the form of features commonly referred to as medians, peninsulas, and islands; (2) must be evenly distributed throughout a parking lot, except that the distribution and location of landscaped area may accommodate existing trees or other natural features if the total area requirement is satisfied; and (3) may count toward compliance with Section 25-2-1003(A) (General Requirements); and 1 (B) (E) (4) must have an edge-of-pavement treatment that allows overland flow of stormwater runoff across the (a) for perimeter landscape areas that are not required to drain to a required stormwater control landscape area except: measure; and (b) for sites located within the Edwards Aquifer Recharge Zone. § 25-2-1008 IRRIGATION REQUIREMENTS. (A) An area equal to at least 50% of the total required landscaped area on a project must: (1) be undisturbed natural area(s) or undisturbed existing trees with no potable irrigation; or (2) be irrigated by stormwater runoff conveyed from impervious surfaces on the site using one or more of the following methods: (a) overland flow; (b) (c) (d) (e) (f) storm drains; downspouts; rainwater harvesting; retention-irrigation; or other methods of conveyance as prescribed by rule. (B) The drainage area used to irrigate under Subsection (A) must be calculated to provide sufficient water for the landscaped area, as prescribed by rule. (C) Unless the landscaped area under Subsection (A) is being designed as a water quality control under Section 25-8-211, the drainage area used to irrigate the landscaped area that is the source of the overland flow: (1) may not include impervious areas on which the land use or activities may generate highly contaminated runoff, as prescribed by rule; and (2) may not include impervious areas used for parking or driving of vehicles if located within the Edwards Aquifer Recharge Zone as defined in Section 25-8-2. (AD) No permanent irrigation is required for all or a portion of a required landscaped area that consists of: (1) undisturbed natural area; or (2) undisturbed existing trees; (BE) In addition to irrigation meeting the requirements of Subsection (A), sSupplemental irrigation using irrigation methods described in Subsection (CF) is required: (1) for the first two growing seasons for all or a portion of a newly planted required landscaped area without permanent irrigation; (2) permanently for all newly planted trees in a required landscape area; and (3) as prescribed by rule for all newly planted required landscaping located in medians, islands, or peninsulas. (CF) Irrigation required under subsection (BE) may be provided only by one or more of the methods described below: (1) (2) the hose attachment is within 100 feet of the landscaped area or plant; and there is not a road or parking pavement between the hose attachment and the landscaped area or plan; or (3) a temporary, above ground automatic irrigation system, if the system complies with the water conservation requirements in the Environmental Criteria Manual. an automatic irrigation system; a hose attachment, if: (a) (b) (DG) An irrigation method must: (1) provide a moisture level adequate to sustain growth of the plant materials on a permanent basis; (2) unless fiscal security is provided to the City for the installation of the system, be operational at the time of the final landscape inspection; and (3) be maintained and kept operational. (EH) A site plan must show: (1) (2) the drainage area(s) used to irrigate under Subsection (A), including notation of the land uses on impervious areas within the drainage area(s); the nature and location of an irrigation system; and 2 (3) that there is no disturbance to the critical root zone of an existing tree. (FI)The director may grant an administrative variance to the requirements in this Section. An applicant for a variance must demonstrate that: (1) strict compliance with this Section is infeasible due to unique site conditions including but not limited to topography, size, shape, and location of existing features such as trees or previous development; and (2) the proposed irrigation plan is the minimal departure from the requirements of this Section. Functional Green. (A) Applicability. (1) This division/article applies Chapter 25-2 (Zoning); and (a) In an Urban watershed, for a site with an impervious cover limit greater than 80% as allowed in (b) In a watershed other than Urban, for a site with total allowable impervious cover greater than 80% gross site area as per Chapter 25-8 (Environment). (B) The Functional Green score shall be calculated as follows: (1) Identify all proposed landscape elements, sorted into the categories presented in Table A. (2) Multiply the square feet, or equivalent square footage where applicable, of each landscape element by the multiplier provided in Table A, according to the following provisions: (a) If multiple elements listed on Table A occupy the same area (for example, groundcover under a tree), count the full square footage or equivalent square footage of each element. (b) Landscaping elements in the right-of-way between the lot line and the roadway may be counted. (c) Elements listed in Table A that are provided to satisfy any other requirements of another City of Austin regulation or rule may be counted. (d) Ensure that Functional Green landscapes provide a variety of ecosystem services by providing a minimum of 3 different Functional Green Landscape Elements, 2 of which must be living elements; trees and shrubs/ornamental grasses of different sizes may count independently as different elements. 3. Add together all the products calculated under Table A to determine the Functional Green numerator. 4. Divide the Functional Green numerator by the lot area (excluding the ROW area) to determine the Functional Green score. TABLE No. TBD PLANTED AREA Existing tree Landscape element Large, newly planted tree (mature width 40’ or greater) Medium, newly planted tree (mature width 20-39’) Small, newly planted tree (mature width 10- 19’) Large shrubs, ornamental grasses, or perennial forbs Small shrubs, ornamental grasses, or perennial forbs Groundcover A B.1 B.2 B.3 C.1 C.2 D Multiplier 0.8 0.6 0.5 0.4 0.3 0.3 0.2 3 Turf Vegetated wall SPECIALIZED MEDIA Intensive vegetated (green) roof media (depth 12 inches or greater) Extensive vegetated (green) roof media (depth 6-11.9 inches) H.1 H.2 E F G I J K L Rain garden Media ADDITIONAL ELEMENTS Irrigation with alternative water source Porous pavement Suspended pavement system BONUS OPTIONS Bonus: Pollinator resources M Bonus: Publicly Accessible Green (C) Requirements. A Functional Green Landscape plan is required to: 0.1 0.5 0.6 0.5 0.3 0.2 0.2 0.2 0.05 0.05 1. Meet or exceed the minimum Functional Green Score of 0.3. 2. Except for property zoned central business district or downtown mixed use district, comply with landscape requirements for a site plan, per Chapter 25-2, Subchapter C, Article 9 and the Environmental Criterial Manual. 3. Provide 100 percent of plant selections, as prescribed by the Environmental Criteria Manual 4. Provide 100 percent drought tolerant plants, as prescribed by the Environmental Criteria Manual. 5. Add the following note to the landscape plan: “This landscape plan uses the Functional Green scoring system. A site plan revision is required to modify the landscape plan.” ARTICLE 13. - DOCKS, BULKHEADS, AND SHORELINE ACCESS. § 25-2-1179 ENVIRONMENTAL PROTECTION. (A) In addition to other applicable requirements of this title, a dock, bulkhead, or shoreline access must be designed, constructed, and maintained in accordance with the applicable requirements of this subsection. (B) A retaining wall, bulkhead, or other erosion protection device must be designed and constructed to minimize wave return and wave action in accordance with the Environmental Criteria Manual. (BC) A marine fuel facility or service station must comply with the requirements of Chapter 6-2 (Hazardous Materials) and shall be designed, maintained, and operated in a manner that prevents the spilling or leaking of fuel or petroleum products into the water. (CD) The maintenance and repair of watercraft shall be performed in a manner that prevents discharge of fuel, oil, or other pollutants into the water. (DE) Containers of hazardous materials, fuel, oil, herbicides, insecticides, fertilizers or other pollutants may not be stored on docks extending into or above Lake Austin, Lady Bird Lake, or Lake Walter E. Long. (EF) Construction of shoreline access structures must minimize disturbance to woody and herbaceous vegetation, preserve the tree canopy, and replace herbaceous ground cover to the extent practicable. 4 (FG) A marina or marine fuel service facility or service station must provide adequate fire protection approved by the Fire Chief of the Austin Fire Department in accordance with the Fire Code and National Fire Protection Association standards for marinas and boatyards. CHAPTER 25-5. SITE PLANS § 25-5-3 SMALL PROJECTS. (A) The director shall determine whether a project is a small project described in this section. (B) The following are small projects: (1) construction of a building or parking area if the proposed construction: (a) does not require a variance from a water quality regulation; (b) does not exceed 5,000 square feet of impervious cover; and (c) the construction site does not exceed 10,000 square feet, including the following areas: construction; (i) (ii) clearing; (iii) grading; (iv) (v) (vi) construction equipment access; driveway reconstruction; temporary installations, including portable buildings, construction trailers, storage areas for building materials, spoil disposal areas, erosion and sedimentation controls, and construction entrances; landscaping; and (vii) (viii) other areas that the director determines are part of the construction site; (3) (2) construction of a storm sewer not more than 30 inches in diameter that is entirely in a public right-of- way or an easement; construction of a utility line not more than eight inches in diameter that is entirely in a public right-of- way; construction of a left turn lane on a divided arterial street; construction of street intersection improvements; (4) (5) (6) widening a public street to provide a deceleration lane if additional right-of-way is not required; (7) depositing less than two feet of earth fill, if the site is not in a 100 year floodplain and the fill is not to (8) (9) be deposited within the dripline of a protected tree; construction of a boat dock as an accessory use to a single-family residential use, duplex residential use, two-family residential use, or secondary apartment special use if shoreline modification or dredging of not more than 25 cubic yards is not required; or construction of a retaining wall, if the wall is less than 100 feet in length and less than eight feet in height, and the back fill does not reclaim a substantial amount of land except land that has eroded because of the failure of an existing retaining wall; (10) minor development that the director determines is similar to that described in Subsections (B)(1) through (9) of this section; (11) the replacement of development that is removed as a result of right-of-way condemnation; and (12) the construction of a telecommunications tower described in Subsection 25-2-839(F) or (G) (Telecommunication Towers); and. (13) construction of a multi-family residential project of up to 11 units on a platted residential lot, unless an additional number of units is allowed for a qualifying development participating in the Affordability Unlocked Bonus Program (Chapter 25-1, Article 15, Division 4), that: (a) is not located within in the Barton Springs Zone; (b) does not exceed 45% impervious cover; (c) is located on a lot that was originally part of a single family residential subdivision; and (d) is located on a site of less than half an acre. 5 (C) Notwithstanding any other provisions in this Section, construction of Shoreline Access, as defined in Section 25-2-1172, that exceeds 50 feet in length and is constructed on slopes exceeding 35% gradient does not constitute a small project. For a small project, the director may waive a submittal requirement that the director determines is not essential to demonstrate compliance with this title. The director shall maintain a record of submittal requirements that are waived under this subsection. (D) CHAPTER 25-7. DRAINAGE § 25-7-32 DIRECTOR AUTHORIZED TO REQUIRE EROSION HAZARD ZONE ANALYSIS. (A) The director may require the owner of real property to provide, at the owner's expense and as a condition for development application approval, an analysis to establish the erosion hazard zone if the proposed development is: (1) within 100 feet of the centerline of a waterway with a drainage area of 64 acres or greater; or (2) within 100 400 feet of the ordinary high water mark of the Colorado River downstream from Longhorn Dam, as defined by Code of Federal Regulations Title 33, Section 328.3 (Definitions), unless additional distance is required as determined by the Director; or located where significant erosion is present as determined by the director. (3) The erosion hazard zone analysis must be in accordance with the Drainage Criteria Manual. If an erosion hazard zone analysis is required under this section, the City may not accept for review a development application for any portion of the proposed development until the director has received the required erosion hazard zone analysis. (B) (C) CHAPTER 25-8 SUBCHAPTER A. WATER QUALITY. § 25-8-1 DEFINITIONS. In this subchapter: (1) BARTON SPRINGS means the springs that comprise the Barton Springs complex associated with Barton Springs Pool, and includes Upper Barton, Old Mill, Eliza, and Parthenia springs. (2) BLUFF means a vertical change in elevation of more than 40 feet and an average gradient greater than 400 percent. (3) CANYON RIMROCK means a rock substrate that: (a) (b) has a gradient that exceeds 60 percent for a vertical distance of at least four feet; and is exposed for at least 50 feet horizontally along the rim of the canyon. (4) COMMERCIAL DEVELOPMENT means all development other than open space and residential development. (5) CLUSTER HOUSING means a residential housing development that maximizes common open space by grouping housing units to minimize individual yards and has a maximum lot area of fifteen thousand (15,000) square feet for detached residential development. (6) CRITICAL ENVIRONMENTAL FEATURES means features that are of critical importance to the protection of environmental resources, and includes bluffs, canyon rimrocks, caves, faults and fractures, seeps, sinkholes, springs, and wetlands. (7) DIRECTOR, when used without a qualifier, means the director of the Planning and Development (8) (9) Review Watershed Protection Department, or the director's designee. EROSION HAZARD ZONE means an area where future stream channel erosion is predicted to result in damage to or loss of property, buildings, infrastructure, utilities, or other valued resources. FAULTS AND FRACTURES means significant fissures or cracks in rock that may permit infiltration of surface water to underground cavities or channels. 6 (10) FLOODPLAIN MODIFICATION means development that results in any vertical or horizontal change in the cross section of the 100-year floodplain as determined under Section 25-7-6 (Determination of the 100-Year Floodplain). IMPERVIOUS COVER means the total area of any surface that prevents the infiltration of water into the ground, such as roads, parking areas, concrete, and buildings. (11) (12) MULTI-USE TRAIL means a facility designated for the use of pedestrians, bicycles, and/or other non- motorized users and associated bridges. (13) OPEN SPACE means a public or private park, multi-use trail, golf cart path, the portions of a golf course left in a natural state, and an area intended for outdoor activities which does not significantly alter the existing natural vegetation, drainage patterns, or increase erosion. OPEN SPACE does not include parking lots. (14) OWNER includes a lessee. (15) POINT RECHARGE FEATURE means a cave, sinkhole, fault, joint, or other natural feature that lies over the Edwards Aquifer recharge zone and that may transmit a significant amount of surface water into the subsurface strata. (16) WATER QUALITY CONTROL means a structure, system, or feature that provides water quality benefits by treating stormwater run-off. (17) WETLAND means a transitional land between terrestrial and aquatic systems where the water table is usually at or near the surface or the land is covered by shallow water, and conforms to the Army Corps of Engineers' definition. § 25-8-2 DESCRIPTIONS OF REGULATED AREAS. (A) This section describes the watersheds, aquifers, and other water quality protection zones that are regulated by this subchapter. A map of these areas is shall be maintained by the Watershed Protection Department and made available for reference inspection online and at the offices of the Planning and Development Review Development Services Department. The director of the Watershed Protection Department shall determine the boundaries of the areas described in Subsection (D). The director of the Watershed Protection Department may require an applicant to verify the boundary of an area described in Subsection (D). For property within 1,500 feet of an Edwards Aquifer recharge zone boundary, the director of the Watershed Protection Department may require that an applicant provide a certified report from a geologist or hydrologist verifying the boundary location. In this subchapter: (B) (C) (D) (1) BARTON SPRINGS ZONE means the Barton Creek watershed and all watersheds that contribute recharge to Barton Springs, including those portions of the Williamson, Slaughter, Onion, Bear and Little Bear Creek watersheds located in the Edwards Aquifer recharge or contributing zones. (2) BARTON CREEK WATERSHED means the land area that drains to Barton Creek, including Little Barton (3) (4) (5) (6) (7) Creek watershed. EDWARDS AQUIFER is the water-bearing substrata that includes the stratigraphic rock units known as the Edwards Group and Georgetown Formation. EDWARDS AQUIFER CONTRIBUTING ZONE means all land generally to the west and upstream of the Edwards Aquifer recharge zone that provides drainage into the Edwards Aquifer recharge zone. EDWARDS AQUIFER RECHARGE ZONE means all land over the Edwards Aquifer that recharges the aquifer, as determined by the surface exposure of the geologic units comprising the Edwards Aquifer, including the areas overlain with quaternary terrace deposits. SOUTH EDWARDS AQUIFER RECHARGE ZONE means the portion of the Edwards Aquifer recharge zone that is located south of the Colorado River and north of the Blanco River. SUBURBAN WATERSHEDS include all watersheds not otherwise classified as urban, water supply suburban, or water supply rural watersheds, and include: 7 the Brushy, Buttercup, Carson, Cedar, Cottonmouth, Country Club East, Country Club West, Decker, Dry Creek East, Elm Creek, Elm Creek South, Gilleland, Harris Branch, Lake, Lockwood, Maha, Marble, North Fork Dry, Plum, Rattan, Rinard, South Boggy, South Fork Dry, South Brushy, Walnut, and Wilbarger creek watersheds; the Colorado River watershed downstream of U.S. 183; and those portions of the Onion, Bear, Little Bear, Slaughter, and Williamson creek watersheds not located in the Edwards Aquifer recharge or contributing zones. (8) URBAN WATERSHEDS include: the Blunn, Buttermilk, Boggy, East Bouldin, Fort, Harper Branch, Johnson, Little Walnut, Shoal, Tannehill, Waller, and West Bouldin creek watersheds; the north side of the Colorado River watershed from Johnson Creek to U.S. 183; and the south side of the Colorado River watershed from Barton Creek to U.S. 183. (9) WATER SUPPLY RURAL WATERSHEDS include: the Lake Travis watershed; the Lake Austin watershed, excluding the Bull Creek watershed and the area to the south of Bull Creek and the east of Lake Austin; and the Bear West, Bee, Bohl's Hollow, Cedar Hollow, Coldwater, Commons Ford, Connors, Cuernavaca, Harrison Hollow, Hog Pen, Honey, Little Bee, Panther Hollow, Running Deer, St. Stephens, Steiner, and Turkey Creek watersheds. (10) WATER SUPPLY SUBURBAN WATERSHEDS include: the Bull, Eanes, Dry Creek North, Huck's Slough, Taylor Slough North, Taylor Slough South, and West Bull creek watersheds; the Lady Bird Lake watershed on the south side of Lady Bird Lake from Barton Creek to Tom Miller Dam; the Lady Bird Lake watershed on the north side of Lady Bird Lake from Johnson Creek to Tom Miller Dam; and the Lake Austin watershed on the east side of Lake Austin from Tom Miller Dam to Bull Creek. (a) (b) (c) (a) (b) (c) (a) (b) (c) (a) (b) (c) (d) Division 2. Applicability; Exemptions; Exceptions. § 25-8-21 APPLICABILITY. (A) Except as provided in Subsections (B) and (C), this subchapter applies in the planning jurisdiction. (B) For a preliminary plan, final plat, or subdivision construction plan in the portion of the city's extraterritorial jurisdiction that is within Travis County: (1) (2) this subchapter does not apply; and Title 30 (Austin/Travis County Subdivision Regulations) governs. (C) The following requirements of this subchapter apply to residential construction of one to eleven units; (1) 25-8-261 Critical Water Quality Zone Restrictions, for a legal tract or a lot platted on or after May 18, 1986, and for development associated with boat docks, shoreline access, or shoreline modifications including bulkheads and bank stabilization; (2) 25-8-63 Impervious Cover Calculations; (3) 25-8 Article 2 Waterways Classified; Zones Established for a legal tract or a lot platted on or after May 18, 1986, and for development associated with boat docks, shoreline access, or shoreline modifications including bulkheads and bank stabilization; (4) 25-8 Article 5 Erosion and Sedimentation Control; Overland Flow; (5) 25-8-321 Clearing of Vegetation; (6) 25-8-323 Temporary Storage Areas; Topsoil Protection (7) 25-8-341 Cut Requirements; 8  (8) 25-8-342 Fill Requirements; (9) 25-8-364 Floodplain Modifications for a legal tract or a lot platted on or after May 18, 1986, and for development associated with boat docks, shoreline access, or shoreline modifications including bulkheads and bank stabilization; (10) 25-8-368 Restrictions on Development Impacting Lake Austin, Lady Bird Lake, and Lake Walter E Long; (11) Article 13 Save Our Springs (D) Compliance with municipal regulatory restrictions on a recorded plat or covenant is required, to the extent the director determines that the restrictions are applicable. § 25-8-25 REDEVELOPMENT EXCEPTION IN URBAN AND SUBURBAN WATERSHEDS. (A) This section applies to property located in an urban or suburban watershed that has existing development if: (1) no unpermitted development occurred on the site after January 1, 1992, and Any development constructed without a permit after January 1, 1992 will be removed from the site and the area restored to pre-development conditions; and the property owner files a site plan application and an election for the property to be governed by this section. The applicant files a site plan application or concurrent subdivision and site plan applications and elects for the property to be governed by this section. (2) (B) The requirements of this subchapter do not apply to the subdivision of property if at the time of redevelopment under this section subdivision and site plan applications are filed concurrently. (CB) The requirements of this subchapter do not apply to the redevelopment of the property if the redevelopment: (1) does not increase the existing amount of impervious cover on the site; (2) removes existing impervious cover from within 50 feet of the centerline of a classified waterway, or 50’ from the shoreline of a lake, or 100’ from the Ordinary High Water Mark of the Colorado River, and revegetates the area as prescribed in the Environmental Criteria Manual; (23) provides the level of water quality treatment prescribed by current regulations for the redeveloped area or an equivalent area on the site; (3) does not generate more than 2,000 vehicle trips a day above the estimated traffic level based on the most recent authorized use on the property; is consistent with the neighborhood plan adopted by council, if any; (4) (54) does not increase non-compliance, if any, with Article 7, Division 1 (Critical Water Quality Zone Restrictions), Section 25-8-281 (Critical Environmental Features), or Section 25-8-282 (Wetland Protection); and (5) complies with Article 3 (Environmental Resource Inventory; Pollutant Attenuation Plan) and all construction phase environmental standards in effect at the time of construction, including Article 5 (Erosion and Sedimentation Control; Overland Flow); and (6) does not place redevelopment within the Erosion Hazard Zone, unless protective works are provided as prescribed in the Drainage Criteria Manual. (D) The redevelopment must comply with Section 25-8-121 (Environmental Resource Inventory Requirement) and all construction phase environmental requirements in effect at the time of construction, including Chapter 25-8, Article 5 (Erosion and Sedimentation Control; Overland Flow). § 25-8-26 REDEVELOPMENT EXCEPTION IN THE BARTON SPRINGS ZONE. (A) This section applies to property located in the Barton Springs Zone that has existing commercial development if: (1) no unpermitted development occurred on the site after January 1, 1992, and (2) the property owner files a site plan application and an election for the property to be governed by this section. 9 (B) (C) For property governed by this section, this section supersedes Article 13 (Save Our Springs Initiative), to the extent of conflict. In this section: (1) (2) SEDIMENTATION/FILTRATION POND STANDARD POND means water quality controls that comply with Section 25-8-213 (Water Quality Control Standards) or are approved under Section 25-8-151 (Innovative Management Practices); and SOS POND means water quality controls that comply with all requirements of Section 25-8-213 (Water Quality Control Standards) and the pollutant removal requirements of Section 25-8-514(A) (Pollution Prevention Required). (D) The requirements of this subchapter do not apply to the subdivision of property if at the time of redevelopment under this section subdivision and site plan applications are filed concurrently. The requirements of this subchapter do not apply to the redevelopment of property if the redevelopment meets all of the following conditions: (E) (1) (2) (3) (4) (5) (6) The redevelopment may not increase the existing amount of impervious cover on the site. The redevelopment may not increase non-compliance, if any, with Article 7, Division 1 (Critical Water Quality Zone Restrictions), Section 25-8-281 (Critical Environmental Features), Section 25-8-282 (Wetland Protection), or Section 25-8-482 (Water Quality Transition Zone). The redevelopment must comply with Section 25-8-121Article 3 (Environmental Resource Inventory Requirement; Pollution Attenuation Plan) and all construction phase environmental requirements in effect at the time of construction, including Chapter 25-8, Article 5 (Erosion and Sedimentation Control; Overland Flow) and Section 25-8-234 (Fiscal Security in the Barton Springs Zone). The water quality controls on the redevelopment site must provide a level of water quality treatment that is equal to or greater than that which was previously provided. For a commercial or multifamily redevelopment, the owner or operator must obtain a permit under Section 25-8-233 (Barton Springs Zone Operating Permit) for both sedimentation/filtration standard ponds and SOS ponds. For a site with more than 40 percent net site area impervious cover, the redevelopment must have: (a) (b) sedimentation/filtration standard ponds for the entire site; or SOS ponds for a portion of the site, and sedimentation/filtration standard ponds for the remainder of the redeveloped site. (7) (8) For a site with 40 percent or less net site area impervious cover, the redevelopment must have SOS ponds for the entire site. The property owner must mitigate the effects of the redevelopment, if required by and in accordance with Subsection (H). (9) Redevelopment may not be located within the Erosion Hazard Zone, unless protective works are provided as prescribed in the Drainage Criteria Manual. (F) City Council approval of a redevelopment in accordance with Subsection (G) is required if the redevelopment: includes more than 25 dwelling units; is located outside the City's zoning jurisdiction; is proposed on property with an existing industrial or civic use; is inconsistent with a neighborhood plan; or (1) (2) (3) (4) (5) will generate more than 2,000 vehicle trips a day above the estimated traffic level based on the most recent authorized use on the property. (G) City Council shall consider the following factors in determining whether to approve a proposed redevelopment: (1) benefits of the redevelopment to the community; 10 (2) whether the proposed mitigation or manner of development offsets the potential environmental impact of the redevelopment; the effects of offsite infrastructure requirements of the redevelopment; and compatibility with the City's comprehensive plan. (3) (4) (H) Redevelopment of property under this section requires the purchase or restriction of mitigation land if the site has a sedimentation/filtration pond. (1) (2) The combined gross site area impervious cover of the mitigation land and the portion of the redevelopment site treated by sedimentation/filtration ponds may not exceed 20 percent. The mitigation requirement may be satisfied by: (a) (b) (c) (d) (a) (b) (c) (d) (e) (f) (g) paying into the Barton Springs Zone Mitigation Fund a non-refundable amount established by ordinance; transferring to the City in accordance with Paragraph (3) mitigation land approved by the director of the Watershed Protection Department within a watershed that contributes recharge to Barton Springs, either inside or outside the City's jurisdiction; placing restrictions in accordance with Paragraph (3) on mitigation land approved by the director of the Watershed Protection Department within a watershed that contributes recharge to Barton Springs, either inside or outside the City's jurisdiction; or a combination of the mitigation methods described in Subparagraphs (a) - (c), if approved by the director of the Watershed Protection Department. (3) A person redeveloping under this section shall pay all costs of restricting the mitigation land or transferring the mitigation land to the City, including the costs of: an environmental site assessment without any recommendations for further clean-up, certified to the City not earlier than the 120th day before the closing date transferring land to the City; a category 1(a) land title survey, certified to the City and the title company not earlier than the 120th day before the closing date transferring land to the City; a title commitment with copies of all Schedules B and C documents, and an owner's title policy; a fee simple deed, or, for a restriction, a restrictive covenant approved as to form by the city attorney; taxes prorated to the closing date; recording fees; and charges or fees collected by the title company. (I) The Watershed Protection Department shall adopt rules to identify criteria for director approval under this section to ensure that the proposed mitigation, manner of development, and water quality controls offset the potential environmental impact of the redevelopment. § 25-8-27 REDEVELOPMENT EXCEPTION IN THE WATER SUPPLY RURAL AND WATER SUPPLY SUBURBAN WATERSHEDS. (A) This section applies to property located in a water supply rural or water supply suburban watershed that has existing commercial development or existing residential development with greater than two dwelling units per lot if: (1) (2) any development constructed without a permit after January 1, 1992 will be removed from the site and the area restored to pre-development conditions no unpermitted development occurred on the site after January 1, 1992, and the applicant files a site plan application or concurrent subdivision and site plan applications and elects for the property to be governed by this section the property owner files a site plan application and an election for the property to be governed by this section. 11 (B) (C) In this section, SEDIMENTATION/FILTRATION POND STANDARD POND means water quality controls that comply with Section 25-8-213 (Water Quality Control Standards) or are approved under Section 25-8-151 (Innovative Management Practices). The requirements of this subchapter do not apply to the subdivision of property if at the time of redevelopment under this section subdivision and site plan applications are filed concurrently. (D) The requirements of this subchapter do not apply to the redevelopment of property if the redevelopment meets all of the following conditions: (1) (2) (3) (4) (5) (3) (4) (1) (2) The redevelopment may not increase the existing amount of impervious cover on the site. The redevelopment may not increase non-compliance, if any, with Article 7, Division 1 (Critical Water Quality Zone Restrictions), Section 25-8-281 (Critical Environmental Features), Section 25-8-282 (Wetland Protection), Section 25-8-422 (Water Quality Transition Zone), or Section 25-8-452 (Water Quality Transition Zone). (2) The redevelopment must remove any existing impervious cover from within 50 feet of the centerline of a classified waterway or 50’ from the shoreline of a lake and revegetate the area as prescribed in the Environmental Criteria Manual. The redevelopment must comply with Section 25-8-121Article 3 (Environmental Resource Inventory Requirement; Pollutant Attenuation Plan) and all construction phase environmental requirements in effect at the time of construction, including Chapter 25-8, Article 5 (Erosion and Sedimentation Control; Overland Flow). The water quality controls for the redeveloped areas or an equivalent area on the site must provide a level of water quality treatment that is equal to or greater than that which was previously provided. At a minimum, the site must provide sedimentation/filtration standard ponds for the redeveloped area or an equivalent area on the site. The property owner applicant must mitigate the effects of the redevelopment, if required by and in accordance with Subsection (G). (6) Redevelopment may not be located within the Erosion Hazard Zone, unless protective works are provided as prescribed in the Drainage Criteria Manual. (E) City Council approval of a redevelopment in accordance with Subsection (F) is required if the redevelopment: includes more than 25 additional dwelling units; is located outside the City's zoning jurisdiction; is proposed on property with an existing industrial use; is inconsistent with a neighborhood plan; or (1) (2) (3) (4) (5) will generate more than 2,000 vehicle trips a day above the estimated traffic level based on the most recent authorized use on the property. (F) City Council shall consider the following factors in determining whether to approve a proposed redevelopment: (1) benefits of the redevelopment to the community; (2) whether the proposed mitigation or manner of development offsets the potential environmental impact of the redevelopment; the effects of off-site infrastructure requirements of the redevelopment; and compatibility with the City's comprehensive plan. (G) Redevelopment of property under this section requires the purchase or restriction of mitigation land. The combined impervious cover of the mitigation land and the portion of the redevelopment treated by sedimentation/filtration ponds may not exceed 20 percent of gross site area if in a water supply rural watershed or 40 percent of gross site area if in a water supply suburban watershed. The mitigation requirement may be satisfied by: (a) paying into the Water Supply Mitigation Fund a nonrefundable amount established by ordinance; 12 transferring to the City in accordance with Paragraph (3) mitigation land approved by the director of the Watershed Protection Department within a water supply rural or water supply suburban watershed, either inside or outside the City's jurisdiction; placing restrictions in accordance with Paragraph (3) on mitigation land approved by the director of the Watershed Protection Department within a water supply rural or water supply suburban watershed, either inside or outside the City's jurisdiction; or a combination of the mitigation methods described in Subparagraphs (a)—(c), if approved by the director of the Watershed Protection Department. (3) An applicant person redeveloping under this section shall pay all costs of restricting the mitigation land or transferring the mitigation land to the City, including the costs of: an environmental site assessment without any recommendations for further clean-up, certified to the City not earlier than the 120th day before the closing date transferring land to the City; a category 1(a) land title survey, certified to the City and the title company not earlier than the 120th day before the closing date transferring land to the City; a title commitment with copies of all Schedule B and C documents, and an owner's title policy; a fee simple deed, or, for a restriction, a restrictive covenant approved as to form by the City Attorney; taxes prorated to the closing date; recording fees; and charges or fees collected by the title company. (b) (c) (d) (a) (b) (c) (d) (e) (f) (g) (H) The Watershed Protection Department shall adopt rules to identify criteria for director approval under this section to ensure that the proposed mitigation, manner of development, and water quality controls offset the potential environmental impact of the redevelopment. Division 3. Variances. § 25-8-42 ADMINISTRATIVE VARIANCES. (A) A variance under this section may not vary the requirements of Article 13 (Save Our Springs Initiative) and may not be granted for development of a property if any portion of the property abuts or is within 500 feet of the shoreline of Lake Austin, measured horizontally. The director of the Watershed Protection Department may grant a variance from a requirement of: (B) Subsection 25-8-213(C) (Water Quality Control Standards); (1) (21) Section 25-8-261 (Critical Water Quality Zone Development), only if: (a) necessary to protect public health and safety, or if it the type of development requiring the variance would directly contributes to provide a significant, demonstrable environmental benefit, as determined by a functional assessment of floodplain health as prescribed by the Environmental Criteria Manual, (b) necessary to allow an athletic field in existence on October 28, 2013, to be maintained, (c) improved, or replaced, necessary to allow an athletic field to be located in an area not otherwise allowed under Section 25-8-261(B)(5), or (d) necessary to allow a hard surfaced trail to be located in an area not otherwise allowed under Section 25-8-261(B)(3); (e) necessary to allow the specified green stormwater infrastructure to be located in an area not (f) otherwise allowed under Section 25-8-261(H); except in the Barton Springs Zone, necessary to allow a private driveway or private street to cross a Critical Water Quality Zone if the crossing is necessary to provide primary access to the right-of-way or the crossing is required to comply with public health and safety requirements 13 (g) necessary to allow residential use of up to 11 units located on an existing single family platted lot (32) Section 25-8-261 (Critical Water Quality Zone Development), for development within an urban watershed, only if the proposed development: (a) (b) (c) (d) is located not less than 25 feet from the centerline of a waterway, is located outside the erosion hazard zone, unless protective works are provided as prescribed in the Drainage Criteria Manual, does not increase non-compliance, if any, with Article 7, Division 1 (Critical Water Quality Zone Restrictions), Section 25-8-281 (Critical Environmental Features) or Section 25-8-282 (Wetland Protection), and restores native vegetation and soils if development is removed from the Critical Water Quality Zone; (43) Subsection 25-8-262(B) (Critical Water Quality Zone Street Crossings), only outside the Barton Springs Zone; (54) Section 25-8-281 (Critical Environmental Features); (65) Section 25-8-322 (Clearing for a Roadway); (76) Section 25-8-341 (Cut Requirements) or Section 25-8-342 (Fill Requirements), for a cut or fill of not more than eight feet: (a) in the desired development zone; and, (b) for a public primary or secondary educational facility, within the desired development zone or the drinking water protection zone; and or (c) for residential use residential construction of up to 11 units located on an existing single family platted lot. (87) Subsection 25-8-343(A) (Spoil Disposal); (98) Section 25-8-365 (Interbasin Diversion). (109) Subsection 25-8-392(B)(61 (Uplands Zone), Subsection 25-8-392(C)(61 (Uplands Zone), Subsection 25- 8-423(D) (Uplands Zone), or Subsection 25-8-453(El (Uplands Zone). It is the applicant's burden to establish that the findings described in this Section have been met. (C) (D) The director of the Watershed Protection Department may grant a variance described in Subsection (B) only after determining that development in accordance with the variance meets the objective of the requirement for which the variance is requested and: (1) (2) (3) for property in the Barton Springs Zone, the variance will result in water quality that is at least equal to the water quality achievable without the variance; for a variance from Section 25-8-213(C), that the proposed water quality control is necessitated by unique site conditions, excluding any potential loss of impervious cover entitlements resulting from full compliance; for a variance from Section 25-8-261 necessary to allow a private driveway or private street to cross a Critical Water Quality Zone the applicant must demonstrate compliance with the following: a) The crossing must span the active channel or use open bottom culverts as determined by the ; b) In suburban watersheds, Critical Water Quality Zone buffer averaging must be applied to the extent feasible in order to minimize the area of the private driveway within the Critical Water Quality Zone impacted by the crossing; c) The location of the crossing must minimize impacts to critical environmental features, protected and heritage trees, slopes greater than 15%, and must minimize the amount of cut or fill necessary for construction; and (4) d) The construction is not located in the Barton Springs Zone. for a variance from 25-8-261 necessary to allow residential construction of up to 11 units located on an existing single family platted lot if: (1) the modification is the minimum deviation necessary to ensure reasonable use and maintenance of the property for an existing nonconforming structure; 14  (i) the usable lot area cannot accommodate the assumed square footage of impervious cover (2) for new development the director determines that: established under 25-8-64 Impervious Cover Assumptions, after accounting for all applicable regulations; impervious cover established; and (ii) the total proposed impervious cover does not exceed the assumed square footage of (52) for a variance from Section 25-8-261(B)(5), that the proposed work on or placement of the athletic (iii) the development is the minimum deviation necessary to accommodate the development. field will have no adverse environmental impacts; (63) for a variance from Section 25-8-261(H), that the green stormwater infrastructure is: (a) not required for regulatory compliance with 25-8-211 Water Quality Requirement. (b) designed to capture runoff from existing, untreated impervious cover; and (c) proposed in a location that is the minimum necessary departure from the code requirement; (74) for a variance from Section 25-8-281, that the proposed measures development does not include mechanized shoreline access and the proposed measures preserve all characteristics of the critical environmental feature; (85) for a variance from Section 25-8-341 or Section 25-8-342 the cut or fill is not located on a slope with a gradient of more than 15 percent or within 100 feet of a classified waterway; (96) for a variance from Section 25-8-341 or Section 25-8-342 necessary to allow residential construction of up to 11 units located on an existing single family platted lot if: (a) for an existing nonconforming structure, the modification is the minimum deviation necessary to ensure reasonable use and maintenance of the property; or (b) for new development, the director determines that: (i) the usable lot area cannot accommodate the assumed square footage of impervious cover established under 25-8-64 Impervious Cover Assumptions, after accounting for all applicable regulations; (ii) the total proposed impervious cover does not exceed the assumed square footage of impervious cover established; and (iii) the development is the minimum deviation necessary to accommodate the (107) for a variance from Section 25-8-343(A), use of the spoil provides a necessary public benefit. Necessary development. public benefits include: roadways; stormwater detention facilities; public or private park sites; and (a) (b) (c) (d) building sites that comply with Section 25-8-341 (Cut Requirements), Section 25-8-342 (Fill Requirements), and Chapter 25-7 (Drainage); and (118) for a variance from Section 25-8-365, there are no adverse environmental or drainage impacts. (129) or a variance from Subsection 25-8-392(B)(6), Subsection 25-8-392(C)(6), Subsection 25-8-423(D), or Subsection 25-8-453(E), the variance: (a) is the minimum deviation needed to provide necessary improvements for a public mobility project in the right-of-way; and (b) does not create significant adverse environmental impacts. (E) The Watershed Protection Department director shall prepare written findings to support the grant or denial of a variance request under this section. 15  Division 4. Impervious Cover Determinations. § 25-8-62 NET SITE AREA. (A) Net site area includes only the portions of a site that lie in an uplands zone and have not been designated for surface or subsurface wastewater irrigation. For land described in Subsection (A), net site area is the aggregate of: (B) (1) (2) (3) 100 percent of the land with a gradient of 15 percent or less; 40 percent of the land with a gradient of more than 15 percent and not more than 25 percent; and 20 percent of the land with a gradient of more than 25 percent and not more than 35 percent. (C) Net site area does not apply in the urban and suburban watersheds. § 25-8-63 IMPERVIOUS COVER CALCULATIONS. (A) (B) Impervious cover is calculated in accordance with this Section and the Environmental Criteria Manual. Impervious cover calculations include: (1) roads; (2) driveways; (3) parking areas; (4) buildings; concrete; (5) impermeable construction covering the natural land surface; (6) for an uncovered wood deck that has drainage spaces between the deck boards and that is located (7) over a pervious surface, 50 percent of the horizontal area of the deck; and the portion of a site used for the storage of scrap and metal salvage, including auto salvage. (8) (C) Impervious cover calculations exclude: sidewalks in a public right-of-way or public easement; (1) (2) multi-use trails open to the public and located on public land or in a public easement; (3) water quality controls, excluding subsurface water quality controls; (4) detention basins, excluding subsurface detention basins; (5) ground level rainwater harvesting cisterns, excluding subsurface cisterns; (56) drainage swales and conveyances; (67) the water surface area of ground level pools, fountains, and ponds; (78) areas with gravel placed over pervious surfaces that are used only for landscaping or by pedestrians and are not constructed with compacted base; (89) porous pavement designed in accordance with the Environmental Criteria Manual, limited to only pedestrian walkways and multi-use trails, and located outside the Edwards Aquifer Recharge Zone; (910) fire lanes designed as prescribed by the Environmental Criteria Manual, that consist of interlocking pavers, and are restricted from routine vehicle access; (1011) an access ramp for an existing single-family and duplex residential unit if: (a) (b) (c) a person with a disability requires access to a dwelling entrance that meets the requirements of the Residential Code, Section R320.6 (Visitable dwelling entrance); the building official determines that the ramp will not pose a threat to public health and safety; the ramp: (i) is no wider than 48 inches, except that any portion of a landing for the ramp required for turns may be no wider than 60 inches; and (ii) may have a hand railing, but may not have a roof or walls; and 16 (d) the ramp is located in a manner that utilizes existing impervious cover to the greatest extent possible if: (i) (ii) impervious cover on the property is at or above the maximum amount of impervious cover allowed by this title; or if placement of the ramp would result in the property exceeding the maximum amount of impervious cover allowed by this title; and (1112) a subsurface portion of a parking structure if the director of the Watershed Protection Department determines that: (a) the subsurface portion of the structure: (i) (ii) (iii) is located within an urban or suburban watershed; is below the grade of the land that existed before construction of the structure; is covered by soil with a minimum depth of two feet and an average depth of not less than four feet; and (iv) has an area not greater than fifteen percent of the site; (b) (c) (d) the structure is not associated with a use regulated by Section 1.2.2 of Subchapter F of Chapter 25-2 (Residential Design and Compatibility Standards); the applicant submits an assessment of the presence and depth of groundwater at the site sufficient to determine whether groundwater will need to be discharged or impounded; and the applicant submits documentation that the discharge or impoundment of groundwater from the structure, if any, will be managed to avoid adverse effects on public health and safety, the environment, and adjacent property. (13) For purposes of residential building permit review only, no more than two feet of elevated, projecting elements such as eaves, overhangs, cantilevered portions of structures, balconies, awnings, and bay windows. This exemption does not apply to site plans or the calculation of the drainage charge under Section 15-2-5 (Impervious Cover Calculation). § 25-8-64 IMPERVIOUS COVER ASSUMPTIONS. (A) This section applies to impervious cover calculations for duplex or single-family lots. (B) Except as provided in Subsection (C): (1) (2) (3) (4) (5) for each lot greater than three acres in size, 10,000 square feet of impervious cover is assumed; for each lot greater than one acre and not more than three acres in size, 7,000 square feet of impervious cover is assumed; for each lot greater than 15,000 square feet and not more than one acre in size, 5,000 square feet of impervious cover is assumed; for each lot greater than 10,000 square feet and not more than 15,000 square feet in size, 3,500 square feet of impervious cover is assumed; and for each lot not more than 10,000 square feet in size, 2,500 square feet of impervious cover is assumed. (C) For a lot that is restricted to a lesser amount of impervious cover than prescribed by this section, the lesser amount of impervious cover is assumed. The manner in which the lot is restricted is subject to the approval of the director. (D) Except as provided in Subsection (C), this section does not restrict impervious cover on an individual lot. (E) The applicant must demonstrate that all proposed one and two-unit residential lots have usable lot area that can reasonably accommodate the assumed square footage of impervious cover established by Subsection (B). The usable lot area must account for all applicable waterway setbacks, floodplains, steep slopes, critical environmental features, protected trees, on-site sewage facilities, and other relevant code restrictions. 17  ARTICLE 2. WATERWAYS CLASSIFIED; ZONES ESTABLISHED. § 25-8-92 CRITICAL WATER QUALITY ZONES ESTABLISHED. (A) In the water supply rural watersheds, water supply suburban watersheds, and Barton Springs Zone, a critical water quality zone is established along each waterway classified under Section 25-8-91 (Waterway Classifications). (1) The boundaries of a critical water quality zone coincide with the boundaries of the 100-year flood plain as determined under Section 25-7-6 (Determination of the 100-Year Floodplain), except: (a) (b) (c) (d) for a minor waterway, the boundaries of the critical water quality zone are located not less than 50 feet and not more than 100 feet from the centerline of the waterway; for an intermediate waterway, the boundaries of the critical water quality zone are located not less than 100 feet and not more than 200 feet from the centerline of the waterway; for a major waterway, the boundaries of the critical water quality zone are located not less than 200 feet and not more than 400 feet from the centerline of the waterway; and for the main channel of Barton Creek, the boundaries of the critical water quality zone are located 400 feet from the centerline of the creek. (2) Notwithstanding the provisions of Subsections (A)(1)(a), (b), and (c), a critical water quality zone does not apply to a drainage ditch located parallel and adjacent to previously modified drainage feature serving a railroad or public roadway right-of-way if the ditch: that does not possess any natural and traditional character and cannot reasonably be restored to a natural condition, as prescribed in the Envionmental Criteria Manual. (a) was designed and constructed primarily to serve the adjacent railroad or public roadway; (b) is not a segment or modification of a natural waterway; (c) does not possess any natural and traditional character; and (d) cannot reasonably be restored to a natural condition due to existing site constraints. (B) In the suburban watersheds, a critical water quality zone is established along each waterway classified under Section 25-8-91 (Waterway Classifications). (1) (2) (3) (4) for a minor waterway, the boundaries of the critical water quality zone are located 100 feet from the centerline of the waterway; for an intermediate waterway, the boundaries of the critical water quality zone are located 200 feet from the centerline of the waterway; for a major waterway, the boundaries of the critical water quality zone are located 300 feet from the centerline of the waterway; the critical water quality zone boundaries may be reduced to not less than 50 feet from the centerline of a minor waterway, 100 feet from the centerline of an intermediate waterway, and 150 feet from the centerline of a major waterway, and 200 feet from the Ordinary High Water Mark of the Colorado River downstream of the Longhorn Dam if the overall surface area of the critical water quality zone is the same or greater than the surface area that would be provided without the reduction, as prescribed in the Environmental Criteria Manual; and (5) notwithstanding the provisions of Subsections (B)(1), (2), and (3), a critical water quality zone does not apply to a drainage ditch located parallel and adjacent to previously modified drainage feature serving a railroad or public roadway right-of-way if the ditch: that does not possess any natural and traditional character and cannot reasonably be restored to a natural condition. (a) was designed and constructed primarily to serve the adjacent railroad or public roadway; (b) is not a segment or modification of a natural waterway; (c) does not possess any natural and traditional character; and (d) cannot reasonably be restored to a natural condition due to existing site constraints. 18 (C) In an urban watershed, a critical water quality zone is established along each waterway with a drainage area of at least 64 acres. This does not apply in the area bounded by IH-35, Riverside Drive, Barton Springs Road, Lamar Boulevard, and 15th Street. (1) The boundaries of the critical water quality zone coincide with the boundaries of the 100-year floodplain as determined under Section 25-7-6 (Determination of the 100-Year Floodplain), provided that the boundary is not less than 50 feet and not more than 400 feet from the centerline of the waterway. (2) Notwithstanding the provisions of Subsection (C)(1), a critical water quality zone does not apply to a previously modified drainage feature serving drainage ditch located parallel and adjacent to a railroad or public roadway right-of-way if the ditch: that does not possess any natural and traditional character and cannot reasonably be restored to a natural condition. (a) was designed and constructed primarily to serve the adjacent railroad or public roadway; (b) is not a segment or modification of a natural waterway; (c) does not possess any natural and traditional character; and (d) cannot reasonably be restored to a natural condition due to existing site constraints. (D) Critical water quality zones are established to include the inundated areas that constitute Lake Walter E. Long, Lake Austin, Lady Bird Lake, and the Colorado River downstream of Lady Bird Lake. (E) Critical water quality zones are established along and parallel to the shorelines of Lake Travis, Lake Austin, Lady Bird Lake, and Lake Walter E. Long. (1) The shoreline boundary of a critical water quality zone: (a) (b) (c) (d) for Lake Travis, coincides with the 681.0 foot contour line; for Lake Austin, coincides with the 492.8 foot contour line; for Lady Bird Lake, coincides with the 429.0 foot contour line; and for Lake Walter E. Long, coincides with the 554.5 foot contour line. (2) The width of a critical water quality zone, measured horizontally inland, is: (a) (b) 100 feet; or for a detached single-family residential use, 75 feet. (F) Critical water quality zones are established along and parallel to the shorelines of the Colorado River downstream of Lady Bird Lake. (1) The shoreline boundary of a critical water quality zone coincides with the river's ordinary high water mark, as defined by Code of Federal Regulations Title 33, Section 328.3 (Definitions). (2) The width of a critical water quality zone, measured horizontally inland, is 400 feet. The inland boundary of a critical water quality zone coincides with the boundary of the 100-year floodplain as determined under Section 25-7-6 (Determination of the 100-Year Floodplain) except that the width of the critical water quality zone, measured horizontally inland, is not less than 200 feet and not more than 400 feet. ARTICLE 3. ENVIRONMENTAL RESOURCE INVENTORY; POLLUTANT ATTENUATION PLAN. § 25-8-121 ENVIRONMENTAL RESOURCE INVENTORY REQUIREMENT. (A) An applicant shall file an environmental resource inventory with the director for proposed developmentlocated on a tract: (1) within the Edwards Aquifer recharge or contributing zone; (2) within the Drinking Water Protection Zone; (3) containing a water quality transition zone; (24) containing a critical water quality zone; or (35) with a gradient of more than 15 percent; or 19 (4) containing, or within 150 feet of, a potential or verified wetland feature as identified in a map maintained by the Watershed Protection Department and made available for reference online and at the offices of Development Services Department. (B) An environmental resource inventory must: (1) identify critical environmental features and propose protection measures for the features; (2) provide an environmental justification for spoil disposal locations or roadway alignments; (3) propose methods to achieve overland flow; (4) describe proposed industrial uses and the pollution abatement program; and (5) be completed as prescribed by the Environmental Criteria Manual. (C) An environmental resource inventory must include: (1) (2) (3) a hydrogeologic report in accordance with Section 25-8-122 (Hydrogeologic Report); a vegetation report in accordance with Section 25-8-123 (Vegetation Report); and a wastewater report in accordance with Section 25-8-124 (Wastewater Report). (D) The director of the Watershed Protection Department may permit an applicant to exclude from an environmental resource inventory information required by this section after determining that the information is unnecessary because of the scope and nature of the proposed development. ARTICLE 5. EROSION AND SEDIMENTATION CONTROL; OVERLAND FLOW. § 25-8-182 DEVELOPMENT COMPLETION. (A) Development is not completed until: (1) permanent revegetation is established; and (2) the director Planning and Development Review Department: (a) (b) receives the engineer's concurrence letter; and certifies installation of the vegetation for acceptance. (B) Development must be completed under Subsection (A) before the City may accept maintenance responsibility for streets, drainage facilities, or utilities, or issue a certificate of occupancy or compliance, unless the City and the applicant enter into an agreement to ensure completion of the revegetation within a named period. § 25-8-184 ADDITIONAL EROSION AND SEDIMENTATION CONTROL REQUIREMENTS IN THE BARTON SPRINGS ZONE. Barton Springs Zone. (A) This section provides additional erosion and sedimentation control requirements for development in the (B) A temporary erosion and sedimentation control plan and a water quality plan certified by a registered professional engineer and approved by the Planning and Development Review Department director is required. (1) (2) The plans must describe the temporary structural controls, site management practices, or other approved methods that will be used to control of off-site sedimentation until permanent revegetation is certified as completed under Section 25-8-182 (Development Completion). The temporary erosion control plan must be phased to be effective at all stages of construction. Each temporary erosion control method must be adjusted, maintained, and repaired as necessary. (C) The director Planning and Development Review Department may require a modification of the temporary erosion control plan after determining that the plan does not adequately control off-site sedimentation from the development. Approval by the Planning and Development Review Department and the engineer who certified the plan is required for a major modification of the plan. 20 (D) The owner shall designate a project manager who is responsible for compliance with the erosion and (E) (F) sedimentation control and water quality plan requirements during development. The length of time between clearing and final revegetation of development may not exceed 18 months, unless extended by the director. If an applicant does not comply with the deadline in Subsection (E), or does not adequately maintain the temporary erosion and sedimentation controls, the director shall notify the applicant in writing that the City will repair the controls or revegetate the disturbed area at the applicant's expense unless the work is completed or revegetation is begun not later than the 15th day after the date of the notice. (G) A person commits an offense if the person allows sediment from a construction site to enter a waterway by failing to maintain erosion controls or failing to follow the approved sequence of construction. § 25-8-185 OVERLAND FLOW. (A) Drainage patterns must be designed to: (1) prevent erosion; (2) maintain infiltration and recharge of local seeps, and springs, and waterways; (3) (4) where possible, maintain and restore overland sheet flow, maintain natural drainage features and attenuate the harm of contaminants collected and transported by stormwater; and patterns, and disperse runoff back to sheet flow; and (5) where feasible, direct stormwater to landscape areas including islands, medians, peninsulas, and other similar areas. Exceptions to this requirement include: (a) impervious areas on which the land use or activities may generate highly contaminated runoff, as prescribed by rule; and (b) impervious areas used for parking or driving of vehicles if located within the Edwards Aquifer Recharge Zone as defined in Section 25-8-2 (B) The applicant shall design an enclosed storm drain to mitigate potential adverse impacts on water quality by using methods to prevent erosion and dissipate discharges from outlets. Applicant shall locate discharges to maximize overland flow through buffer zones or grass-lined swales wherever practicable. ARTICLE 6. WATER QUALITY CONTROLS. § 25-8-213 WATER QUALITY CONTROL STANDARDS. (A) A water quality control must be designed in accordance with the Environmental Criteria Manual. (1) The control must provide at least the treatment level of a sedimentation/filtration system under the achieve the load reduction standards prescribed in the Environmental Criteria Manual. (2) An impervious liner is required for structural water quality controls over the Edwards Aquifer Recharge Zone in an area where there is surface runoff to groundwater conductivity. If a liner is required and controls are located in series there are multiple controls in series, liners are only required for the first control in the series not required for the second or later in the series following sedimentation, extended detention, or sedimentation/filtration. The control must be accessible for maintenance and inspection as prescribed in the Environmental Criteria Manual. (3) (B) A water quality control must capture and treat the water draining to the control from the contributing area. The required capture volume is: (1) (2) the first one-half inch of runoff; and for each 10 percent increase in impervious cover over 20 percent of gross site area, an additional one- tenth of an inch of runoff. 21 (C) The required water quality treatment must be provided using green stormwater control measures, as prescribed in the Environmental Criteria Manual. (D) Notwithstanding Subsection (C), all or part of the required water quality treatment may be provided using other water quality controls for: (1) areas with land uses or activities that may generate highly contaminated runoff, as described in the Environmental Criteria Manual; (2) a project that provides water quality treatment for currently untreated, developed off-site areas of at least 10 acres in size; or (3) sites with greater than 90 percent gross site area impervious cover. (EC) The location of a water quality control: (1) must avoid recharge features to the greatest extent possible; (2) must be shown on the slope map, preliminary plan, site plan, or subdivision construction plan, as (3) applicable; and in a water supply rural watershed, may not be in the 40 percent buffer zone, unless the control disturbs less than 50% of the buffer, and is located to maximize overland flow and recharge in the undisturbed remainder of the 40 percent buffer zone. (FD) This subsection provides additional requirements for the Barton Springs Zone. (1) Approval by the Watershed Protection Department is required for a proposed water quality control that is not described in the Environmental Criteria Manual. The applicant must substantiate the pollutant removal efficiency of the proposed control with published literature or a verifiable engineering study. (2) Water quality controls must be placed in sequence if necessary to remove the required amount of pollutant. The sequence of controls must be: based on the Environmental Criteria Manual or generally accepted engineering principles; and (a) (b) designed to minimize maintenance requirements. § 25-8-214 OPTIONAL PAYMENT INSTEAD OF STRUCTURAL CONTROLS IN URBAN WATERSHEDS. (A) The director of the Watershed Protection Department shall identify and prioritize water quality control facilities for the urban watersheds in an Urban Watersheds Structural Control Plan. The Environmental Board Commission shall review the plan in January of each year annually. (B) An Urban Watersheds Structural Control Fund is established for use in the design and construction of water (C) quality control facilities in the urban watersheds. Instead of providing the water quality controls required under Section 25-8-211 (Water Quality Control Requirement), in an urban watershed an applicant may request approval to deposit with the City a nonrefundable cash payment, based on a formula established by the council. The director shall review the request and accept or deny the request based on the standards in the Environmental Criteria Manual. (D) The director shall deposit a payment made under Subsection (C) in the Urban Watersheds Structural Control Fund. (E) A Suburban and Water Supply Watersheds Structural Control Fund is established for use in the design and construction of water quality control facilities. (F) For a public mobility project in the right-of-wav that is located in a suburban, water supply suburban, or water supply rural watershed, an applicant may request approval to deposit a nonrefundable cash payment, based on a formula established by the council, with the City instead of providing the water quality controls required under Section 25-8-211 (Water Quality Control Requirement). The director shall review the request and accept or deny the request based on the standards in the Environmental Criteria Manual. (G) The director shall deposit a payment made under Subsection (F) in the Suburban and Water Supply Watersheds Structural Control Fund. 22  Division 2. Maintenance and Inspection. § 25-8-232 DEDICATED FUND. (A) The director of the Finance Department shall establish a dedicated fund to: (1) monitor water quality controls; and (2) maintain water quality controls for single-family and duplex residential development. (B) An applicant shall pay the required fee into the fund: (1) (2) for development that does not require a site plan, when the applicant posts fiscal security for the subdivision or requests that the director of the Development Services Department record the subdivision plat, whichever occurs first; or for development that requires a site plan, when the site plan is approved. (C) The director of the Watershed Protection Department shall administer the fund, allocate the fund for appropriate projects, and report annually to the council regarding the status of the fund and the monitoring and maintenance program described in this section. § 25-8-233 BARTON SPRINGS ZONE OPERATING PERMIT. (A) (B) In the Barton Springs Zone, the owner or operator of a commercial or multifamily development is required to obtain an annual operating permit for the required water quality controls. To obtain an annual operating permit, an applicant must: (1) provide the director Planning and Development Review Department with: (a) (b) a maintenance plan; and the information necessary to verify that the water quality controls are in proper operating condition; and (2) pay the required, nonrefundable fee. (C) The director Planning and Development Review Department may verify that a water quality control is in proper operating condition by either inspecting the water quality control or accepting a report from a registered engineer. (D) The director Planning and Development Review Department shall issue an operating permit after determining that: (1) (2) the applicant has complied with the requirements of Subsection (B); and the water quality controls are in proper operating condition. (E) The director Planning and Development Review Department shall transfer an operating permit to a new owner or operator if, not later than 30 days after a change in ownership or operation, the new owner or operator: signs the operating permit; accepts responsibility for the water quality controls; and (1) (2) (3) documents the transfer on a form provided by the director Planning and Development Review Department. 23  ARTICLE 7. REQUIREMENTS IN ALL WATERSHEDS. Division 1. Critical Water Quality Zone Restrictions Waterway and Floodplain Protection. § 25-8-261 CRITICAL WATER QUALITY ZONE DEVELOPMENT. In all watersheds, development is prohibited in a critical water quality zone except as provided in this Division. Development allowed in the critical water quality zone under this Division shall be revegetated and restored within the limits of construction as prescribed by the Environmental Criteria Manual. (A) A fence that does not obstruct flood flows is permitted in a critical water quality zone. (B) Open space is permitted in a critical water quality zone if a program of fertilizer, pesticide, and herbicide use is approved by the Watershed Protection Department, subject to the conditions in this Subsection. (1) In a water supply rural watershed, water supply suburban, or the Barton Springs Zone, open space is limited to sustainable urban agriculture or a community garden if the requirements in subsection (B)(4) are met, multi-use trails, picnic facilities, and outdoor facilities, excluding stables, corrals for animals and athletic fields. (2) A park with a council-adopted plan master planned park that is approved by the council may include recreational development other than that described in Subsection (B)(1). (3) A hard surfaced trail may cross the critical water quality zone pursuant to Section 25-8-262 (Critical Water Quality Zone Street Crossings). A hard surfaced trail that does not cross the critical water quality zone may be located within the critical water quality zone only if: (a) (b) (c) (d) (e) (f) (g) (a) (b) (c) designed in accordance with the Environmental Criteria Manual; located outside the erosion hazard zone unless protective works are provided as prescribed in the Drainage Criteria Manual; limited to 12 feet in width plus one-foot compacted sub-grade shoulders, unless a wider trail is designated in a Council-adopted plan; located not less than 25 feet from the centerline of a waterway if within an urban watershed; located not less than 50 feet from the centerline of a minor waterway, 100 feet from the centerline of an intermediate waterway, and 150 feet from the centerline of a major waterway if within a watershed other than an urban watershed; located not less than 50 feet from the shoreline of Lake Travis, Lake Austin, Lady Bird Lake, and Lake Walter E. Long, as defined in Section 25-8-92; and located not less than 100 200 feet from the ordinary high water mark of the Colorado River downstream from Longhorn Dam. (4) Open space may include sustainable urban agriculture or a community garden only if: in an urban watershed and located not less than 25 feet from the centerline of a waterway, or in a watershed other than an urban watershed and located not less than 50 feet from the centerline of a minor waterway, 100 feet from the centerline of an intermediate waterway, and 150 feet from the centerline of a major waterway; located not less than 50 feet from the shoreline of Lake Travis, Lake Austin, Lady Bird Lake, and Lake Walter E. Long, as defined in Section 25-8-92; located not less than 100 200 feet from the ordinary high water mark of the Colorado River downstream from Longhorn Dam; (d) designed in accordance with the Environmental Criteria Manual; and (e) limited to garden plots and paths, with no storage facilities or other structures over 500 square feet. (5) In a suburban or urban watershed, open space may include an athletic field only if: 24 (a) (b) (c) (d) in an urban watershed and located not less than 25 feet from the centerline of a waterway, or in a suburban watershed and located not less than 50 feet from the centerline of a minor waterway, 100 feet from the centerline of an intermediate waterway, and 150 feet from the centerline of a major waterway; located not less than 50 feet from the shoreline of Lady Bird Lake and Lake Walter E. Long, as defined in Section 25-8-92; located not less than 100 feet from the ordinary high water mark of the Colorado River downstream from Longhorn Dam; and the owner of the athletic field submits to the Watershed Protection Department a maintenance plan to keep the athletic field well vegetated and minimize compaction, as prescribed in the Environmental Criteria Manual. (C) The requirements of this subsection apply along Lake Travis, Lake Austin, Lake Walter E Long or Lady Bird Lake. (1) A dock, public boat ramp, bulkhead or marina, and necessary access and appurtenances, are permitted in a critical water quality zone subject to compliance with Chapter 25-2, Subchapter C, Article 12 (Docks, Bulkheads, and Shoreline Access). For a single-family residential use, necessary access may not exceed the minimum area of land disturbance required to construct a single means of access from the shoreline to a dock. (2) Disturbed areas must be restored in accordance with the Environmental Criteria Manual and the following requirements: (a) Within a lakefront critical water quality zone, or an equivalent area within 25 feet of a shoreline, restoration must include: (i) (ii) at least one native shade tree and one native understory tree, per 500 square feet of disturbed area; and one native shrub per 150 square feet of disturbed area; and (b) Remaining disturbed areas must be restored per standard specifications for native restoration. (3) Within the shoreline setback area defined by Section 25-2-551 (Lake Austin (LA) District Regulations) and within the overlay established by Section 25-2-180 (Lake Austin (LA) Overlay District), no more than 30 percent of the total number of shade trees of 8 inches or greater, as designated in the Environmental Criteria Manual, may be removed. (4) Before a building permit may be issued or a site plan released, approval by the Watershed Protection Department is required for chemicals used to treat building materials that will be submerged in water. (5) Bank erosion above the 100-year-flood plain may be stabilized within a lakefront critical water quality zone if the restoration meets the requirements of Subsection (B) (2) of this section. (6) A retaining wall, bulkhead, or other erosion protection device must be designed and constructed to minimize wave return and wave action in compliance with the Environmental Criteria Manual. A shoreline modification within the wave action zone with a greater than 45 degree vertical slope for any portion greater than one foot in height is not allowed on or adjacent to the shoreline of a lake, unless the shoreline modification is located within an existing man-made channel. (7) A retaining wall, bulkhead, or other erosion protection device may not capture or recapture land from a lake unless doing so is required to restore the shoreline to whichever of the following boundaries would encroach the least into the lake: (a) the shoreline as it existed 10 years prior to the date of application, with documentation as prescribed by the Environmental Criteria Manual; or (b) the lakeside boundary of the subdivided lot line. 25 (8) A bulkhead may be replaced in front of an existing bulkhead once, if: (a) the existing bulkhead was legally constructed; and (b) construction of the replacement bulkhead does not change the location of the shoreline by more than 6 inches; and (c) the director determines that there is no reasonable alternative to replacement of the bulkhead in the location of the existing bulkhead. (9) Dredging is prohibited unless: (a) the area of dredging is less than 25 cubic yards; and (b) the dredging is necessary for navigation safety. (D) A new utility line or major replacement of an existing utility line, including a storm drain, or a utility easement associated with planned infrastructure, is prohibited in the critical water quality zone, except as provided in subsection (E) or for a necessary crossing. A necessary utility crossing may cross into or through a critical water quality zone only if: (1) (2) (3) (43) the utility line follows the most direct path into or across the critical water quality zone to minimize disturbance, unless boring or tunneling is the proposed method of installation for the entire crossing and all bore pits are located outside of the Critical Water Quality Zone; the depth of the utility line and location of associated access shafts are not located within an erosion hazard zone, unless protective works are provided as prescribed in the Drainage Criteria Manual;and stormwater outfalls must minimize disturbance to the bank of the Colorado River by locating outfalls in upstream drainages where feasible; and in the Barton Springs Zone, the crossing is approved by the director of the Watershed Protection Department. (E) In the urban and suburban watersheds, a new utility line or major replacement of an existing utility line may be located parallel to and within the critical water quality zone if: (1) (2) (3) in an urban watershed and located not less than 50 feet from the centerline of a waterway, or in a watershed other than urban and located not less than 50 feet from the centerline of a minor waterway, 100 feet from the centerline of an intermediate waterway, and 150 feet from the centerline of a major waterway; located not less than 50 feet from the shoreline of Lady Bird Lake and Lake Walter E. Long, as defined in Section 25-8-92; located not less than 100 200 feet from the ordinary high water mark of the Colorado River downstream from Longhorn Dam; (4) designed in accordance with the Environmental Criteria Manual; (5) located outside the erosion hazard zone, unless protective works are provided as prescribed in the Drainage Criteria Manual; and the project includes either riparian restoration of an area within the critical water quality zone equal in size to the area of disturbance in accordance with the Environmental Criteria Manual, or payment into the Riparian Zone Mitigation Fund of a non-refundable amount established by ordinance. (6) (F) In-channel detention basins and in-channel wet ponds are allowed in the critical water quality zone only if: (1) (2) (3) proposed as part of a public capital improvement project or public private partnership; no alternative location is feasible; and designed in accordance with the Environmental Criteria Manual. (G) Floodplain modifications are is prohibited in the critical water quality zone unless the modification proposed: 26 (1) (2) (3) (1) (2) (3) (4) (5) the floodplain modifications proposed are is necessary to address an existing threat to public health and safety, as determined by the director of the Watershed Protection Department; the floodplain modifications proposed would provide a significant, demonstrable environmental benefit, is designed solely to improve floodplain health as determined by a functional assessment of floodplain health as prescribed by the Environmental Criteria Manual; or the floodplain modifications proposed are is the minimum necessary for development allowed in the critical water quality zone under Section 25-8-261 (Critical Water Quality Zone Development), Section 25-8-262 (Critical Water Quality Zone Mobility Crossings), or Section 25-8- 367 (Restrictions on Development Impacting Lake Austin, Lady Bird Lake, and Lake Walter E. Long) as prescribed in the Environmental Criteria Manual. (H) In the urban and suburban watersheds, vegetative filter strips, rain gardens, biofiltration ponds, areas used for irrigation or infiltration of stormwater, or other controls as prescribed by rule are allowed in the critical water quality zone if: in an urban watershed and located not less than 50 feet from the centerline of a waterway, or in a watershed other than urban and located no less than 50 feet from the centerline of a minor waterway, no less than 100 feet from the centerline of an intermediate waterway, and no less than 150 feet from the centerline of a major waterway; located not less than 50 feet from the shoreline of Lady Bird Lake and Lake Walter E. Long, as defined in Section 25-8-92; located not less than 100 200 feet from the ordinary high water mark of the Colorado River downstream from Longhorn Dam; located outside the 100-year floodplain; and located outside the erosion hazard zone, unless protective works are provided as prescribed in the Drainage Criteria Manual. (I) (J) Development associated with power generation, transmission, or distribution at the Decker Creek Power Station is allowed in the critical water quality zone. A residential lot that is 5,750 square feet or less in size may not include any portion of a critical water quality zone. § 25-8-262 CRITICAL WATER QUALITY ZONE MOBILITY CROSSINGS. (A) (B) In an urban watershed, an arterial street, collector street, residential street, or rail line may cross a critical water quality zone of any waterway. This subsection applies in a watershed other than an urban watershed. (1) A major waterway critical water quality zone may be crossed by an arterial street a Level 3, 4, or 5 street or rail line identified in the Transportation Plan. (2) An intermediate waterway critical water quality zone may be crossed by an a Level 2, 3, 4, or 5 street arterial street, collector street or rail lineexcept: (a) (b) a Level 2 collector street crossing must be at least 2,500 feet, measured in creek miles, from a Level 2, collector or Level 3, 4, or 5 street arterial street crossing on the same waterway; or in a water supply suburban or water supply rural watershed, or the Barton Springs Zone, a Level 2 collector street crossing must be at least one mile, measured in creek miles, from a collector or Level 2, 3, 4, or 5 street arterial street crossing on the same waterway. (3) A minor waterway critical water quality zone may be crossed by an a Level 2, 3, 4, or 5 streetarterial street, collector street, or rail line except: (a) a collector Level 2 street crossing must be at least 900 feet, measured in creek miles, from a collector or Level 2, 3, 4, or 5 street arterial street crossing on the same waterway; or 27 (b) in a water supply suburban or water supply rural watershed, or the Barton Springs Zone, a Level 2 collector street crossing must be at least 2,000 feet, measured in creek miles, from a collector or Level 2, 3, 4, or 5 arterial street crossing on the same waterway. (4) A minor waterway critical water quality zone may be crossed by a residential Level 1 or 2 commercial street if necessary to provide access to property that cannot otherwise be safely accessed. (C) In all watersheds, multi-use trails may cross a critical water quality zone of any waterway if: (1) designed in compliance with the Environmental Criteria Manual; and (2) the development demonstrates no additional adverse impact from flood or erosion potential. (D) Notwithstanding subsections (A) and (B) and except in the Barton Springs Zone, a street or driveway may cross the critical water quality zone if the street or driveway is located in a center or corridor as identified on the growth concept map of the Imagine Austin Comprehensive Plan, as adopted by Ordinance No. 20120614- 058, and if the proposed crossing: (1) is necessary to facilitate the development or redevelopment of a designated corridor or center as recommended in the Imagine Austin Comprehensive Plan, Chapter 4 (Shaping Austin: Building the Complete Community), growth concept map and related definitions; and (2) maintains the quality and quantity of recharge if located in a center or corridor designated as a sensitive environmental area in the Edwards Aquifer recharge zone, Edwards Aquifer contributing zone, or the South Edwards Aquifer recharge zone, as determined by the director of the Watershed Protection Department . § 25-8-263 FLOODPLAIN MODIFICATION. (A) Floodplain modification within a critical water quality zone is prohibited except as allowed under Section 25-8-261 (Critical Water Quality Zone Development). All floodplain modifications must: (3) (1) be designed to accommodate existing and fully-vegetated hydraulic conditions; (2) apply sound engineering and ecological practices, prevent and reduce degradation of water quality, and demonstrate the stability and integrity of floodplains and waterways, as prescribed in the Environmental Criteria Manual; restore floodplain health, or provide mitigation if restoration is infeasible, to support natural functions and processes as prescribed in the floodplain modification criteria in the Environmental Criteria Manual; and comply with the requirements of Chapter 25-7 (Drainage), the Drainage Criteria Manual, and the Environmental Criteria Manual. (4) (B) Floodplain modification within a critical water quality zone is prohibited except as allowed under Section 25-8-261 (Critical Water Quality Zone Development). Floodplain modification outside a critical water quality zone is allowed only if the modification proposed: (1) is necessary to protect public health and safety by addressing an existing threat, as determined by the director of the Watershed Protection Department; (2) would provide a significant, demonstrable environmental benefit, as determined by a functional assessment of floodplain health as prescribed by the Environmental Criteria Manual; (3) (4) is located within a floodplain area classified as in fair or poor condition, as determined by a functional assessment of floodplain health, prescribed by the Environmental Criteria Manual; or is necessary for development allowed under Section 25-8-261 (Critical Water Quality Development) or 25-8-262 (Critical Water Quality Zone Street Crossings). (C) All floodplain modifications must: (1) be designed to accommodate existing and fully-vegetated conditions; 28 (2) (3) (1) (2) (3) (4) encourage sound engineering and ecological practices, prevent and reduce degradation of water quality, and encourage the stability and integrity of floodplains and waterways, as prescribed in the floodplain modification criteria in the Environmental Criteria Manual; restore floodplain health, or provide mitigation if restoration is infeasible, to support natural functions and processes as prescribed in the floodplain modification criteria in the Environmental Criteria Manual; and (4) comply with the requirements of Chapter 25-7 (Drainage), the Drainage Criteria Manual, and the Environmental Criteria Manual. Floodplain modification outside a critical water quality zone is allowed only if the modification proposed: is necessary to protect public health and safety by addressing an existing threat, as determined by the director; is designed solely to improve floodplain health, as determined by a functional assessment of floodplain health as prescribed by the Environmental Criteria Manual; is located within a floodplain area classified as in fair or poor condition, as determined by a functional assessment of floodplain health, and provides restoration or mitigation in accordance with the ratios and specifications prescribed in the Environmental Criteria Manual.; or is the minimum modification necessary for development allowed under Section 25-8-261 (Critical Water Quality Development) or 25-8-262 (Critical Water Quality Zone Mobility Crossings). (D) If on-site restoration, as prescribed in the Environmental Criteria Manual, is infeasible and mitigation is required under this Section, it may be satisfied by: (1) paying into the Riparian Zone Mitigation Fund a nonrefundable amount established by ordinance; transferring in fee simple or placing restrictions on mitigation land approved by the director of the (2) Watershed Protection Department and meeting the following conditions: (a) (b) (c) (d) located within the same watershed classification; in accordance with the procedures in Section 25-8-26 (Redevelopment Exception in the Barton Springs Zone), Subsection (H) (3); dedicated to or restricted for the benefit of the City or another entity approved by the director and which the City or other approved entity accepts; an amount proportionate to the amount of area within the existing floodplain that is proposed to be modified, as prescribed in the Environmental Criteria Manual; or (3) a combination of the mitigation methods described in Subparagraphs (1) and (2), if approved by the director of the Watershed Protection Department. Division 2. Protection for Special Features. § 25-8-281 CRITICAL ENVIRONMENTAL FEATURES. (A) Drainage patterns for proposed development must be designed to protect critical environmental features from the effects of runoff from developed areas, and to maintain the catchment areas of recharge features in a natural state. Special controls must be used where necessary to avoid the effects of erosion, or sedimentation, or high rates of flow. (B) A residential lot may not include a critical environmental feature or be located within 50 feet of a critical environmental feature a critical environmental feature buffer zone and may not be located within 50 feet of a critical environmental feature. This subsection prescribes the requirements for critical environmental feature buffer zones. (C) (1) A buffer zone is established around each critical environmental feature described in this subchapter. (a) Except as provided in Subsection (C)(1)(b), the width of the buffer zone is 150 feet from the edge of the critical environmental feature. 29 (b) For a point recharge feature, the buffer zone coincides with the topographically defined catchment basin, except that the width of the buffer zone from the edge of the critical environmental feature is: (i) (ii) (iii) not less than 150 feet; not more than 300 feet; and calculated in accordance with the Environmental Criteria Manual. (2) Within a buffer zone described in this subsection: the natural vegetative cover must be retained to the maximum extent practicable; construction is prohibited; and (a) (b) (c) wastewater disposal or irrigation is prohibited. (3) If located at least 50 feet from the edge of the critical environmental feature, the prohibition of Subsection (C)(2)(b) does not apply to: (a) (b) (c) a yard or a hiking trail; or a recharge basin approved under Section 25-8-213 (Water Quality Control Standards) that discharges to a point recharge feature;. or an innovative runoff management practice approved under Section 25-8-151 (Innovative Management Practices) that is designed to address the standards of this section, enhance the recharge of groundwater and the discharge of springs, and maintain the function of critical environmental features. (4) Perimeter fencing with not less than one access gate must be installed at the outer edge of the buffer (5) zone for all point recharge features. The fencing must comply with the Standard Specifications Manual. The owner must maintain the buffer zone in accordance with standards in the Environmental Criteria Manual to preserve the water quality function of the buffer. (6) All critical environmental feature locations and required setbacks must be shown on preliminary subdivision plans, site plans, and other permits as determined by the director. (7) All critical environmental feature locations must be shown on final plats. (D) When voids in the rock substrate are uncovered during development, the following protocol must be followed: (1) (2) construction in the area of the void must cease while the applicant conducts a preliminary investigation of the void as prescribed by the Environmental Criteria Manual. The applicant shall contact a City of Austin Environmental Inspector to schedule further investigation by the City of the void as prescribed by the Environmental Criteria Manual if the preliminary investigation indicates that the void: is at least one square foot in total area; (a) (b) blows air from within the substrate; (c) (d) potentially transmits groundwater. consistently receives water during any rain event; or (3) Construction may only proceed after mitigation measures are reviewed and approved by the Watershed Protection Department. § 25-8-282 WETLAND PROTECTION. (A) Wetlands must be protected in all watersheds, except in for wetlands located within the area bounded by Interstate 35, Riverside Drive, Barton Springs Road, Lamar Boulevard, and 15th Street that are not associated with the critical water quality zone of Lady Bird Lake. (B) Protection methods for wetlands include: appropriate setbacks that preserve the wetlands or wetland functions; (1) (2) wetland mitigation, including wetland replacement; or 30 (3) wetland restoration or enhancement; or (4) use of a wetlands for water quality controls. (C) The director of the Watershed Protection Department may approve the proposed protection methods.: (1) (2) the removal and replacement of a wetland; or the elimination of setbacks from a wetland that is proposed to be used as a water quality control. Division 4. Clearing. § 25-8-323 TEMPORARY STORAGE AREAS; TOPSOIL PROTECTION. (A) The site plan or subdivision construction plan must designate the areas to be cleared for temporary storage of spoils or construction equipment. Areas cleared for temporary storage must be located and restored in accordance with the Environmental Criteria Manual. (B) During and after site grading operations, the topsoil must be protected and vegetation left in place to the maximum extent practicable; (C) For areas on the site that are to remain pervious post-development, any soils that are compacted during site grading and construction operations must be decompacted in compliance with the Environmental Criteria Manual and the Standard Specifications Manual. Division 5. Cut, Fill, and Spoil. § 25-8-341 CUT REQUIREMENTS. (A) Cuts on a tract of land may not exceed four feet of depth, except: (1) (2) (3) (4) in an urban watershed; in a roadway right-of-way or rail line right-of-way; for construction of a building foundation or swimming pool, excluding the surrounding pool deck; for construction of a water quality control or detention facility and appurtenances for conveyance such as swales, drainage ditches, and diversion berms, if: (a) (b) (c) the design and location of the facility within the site minimize the amount of cut over four feet; the cut is the minimum necessary for the appropriate functioning of the facility; and the cut is not located on a slope with a gradient of more than 15 percent or within 100 feet of a classified waterway; (5) (6) for utility construction or a wastewater drain field, if the area is restored to natural grade; in a state-permitted sanitary landfill or a sand or gravel excavation located in the extraterritorial jurisdiction, if: (a) (b) (c) (d) (a) (b) (c) (d) the cut is not in a critical water quality zone; the cut does not alter a 100-year floodplain; the landfill or excavation has an erosion and restoration plan approved by the City; and all other applicable City Code provisions are met. ; (7) for any cut associated with construction of a multi-use trail, if: the cut is not located on a slope with a gradient of more than 15 percent or within 100 feet of a classified waterway; the cut is limited to no more than eight feet in depth; the cut is located in a public right-of-way or public easement; and the trail is designed in accordance with the Environmental Criteria Manual.; and (8) for construction of a street or driveway necessary to provide primary access if: (a) the construction complies with Division 3 (Construction on Slopes) of this article; (b) the cut is not within a critical water quality zone; (c) the cut is limited to no more than eight feet in depth; 31 (d) the cut over four feet is the minimum amount necessary to comply with safety access requirements and the horizontal and vertical curve requirements of the Transportation Criteria Manual; and (e) there is no other feasible alternative for the street or driveway location. § 25-8-342 FILL REQUIREMENTS. (A) Fill on a tract of land may not exceed four feet of depth, except: in an urban watershed; in a roadway right-of-way or rail line right-of-way; (1) (2) (3) under a foundation with sides perpendicular to the ground, or with pier and beam construction; (4) for construction of a water quality control or detention facility and appurtenances for conveyance such as swales, drainage ditches, and diversion berms, if: (a) (b) (c) the design and location of the facility within the site minimize the amount of fill over four feet; the fill is the minimum necessary for the appropriate functioning of the facility; and the fill is not located on a slope with a gradient of more than 15 percent or within 100 feet of a classified waterway; (5) (6) for utility construction or a wastewater drain field; in a state-permitted sanitary landfill located in the extraterritorial jurisdiction, if: (a) (b) (c) (d) (a) (b) (c) (d) the fill is derived from the landfill operation; the fill is not placed in a critical water quality zone or a 100-year floodplain; the landfill operation has an erosion and restoration plan approved by the City; and all other applicable City Code provisions are met; or (7) for fill associated with construction of a multi-use trail, if: the fill is not located on a slope with a gradient of more than 15 percent or within 100 feet of a classified waterway; the fill is limited to no more than eight feet in depth; the fill is located in a public right-of-way or public easement; and the trail is designed in accordance with the Environmental Criteria Manual.; or (8) for construction of a street or driveway necessary to provide primary access if: the fill is limited to no more than eight feet in depth; (a) the construction complies with Division 3 (Construction on Slopes) of this article; (b) the fill is not in a critical water quality zone; (c) (d) the fill over four feet is the minimum amount necessary to comply with safety access requirements and the horizontal and vertical curve requirements of the Transportation Criteria Manual; and (e) there is no other feasible alternative for driveway location. (B) A fill area must be restored and stabilized. (C) Fill for a roadway must be contained within the roadway clearing width described in Section 25-8-322 (Clearing For A Roadway). Division 6. Other Restrictions. § 25-8-364 FLOODPLAIN MODIFICATION. (A) Floodplain modification within a critical water quality zone is prohibited except as allowed under Section 25-8-261 (Critical Water Quality Zone Development). Floodplain modification outside a critical water quality zone is allowed only if the modification proposed: (B) (1) is necessary to protect public health and safety by addressing an existing threat, as determined by the director of the Watershed Protection Department; 32 (2) would provide a significant, demonstrable environmental benefit, as determined by a functional (3) (4) assessment of floodplain health as prescribed by the Environmental Criteria Manual; is located within a floodplain area classified as in fair or poor condition, as determined by a functional assessment of floodplain health, prescribed by the Environmental Criteria Manual; or is necessary for development allowed under Section 25-8-261 (Critical Water Quality Development) or 25-8-262 (Critical Water Quality Zone Street Crossings). (C) All floodplain modifications must: (1) be designed to accommodate existing and fully-vegetated conditions; (2) encourage sound engineering and ecological practices, prevent and reduce degradation of water quality, and encourage the stability and integrity of floodplains and waterways, as prescribed in the floodplain modification criteria in the Environmental Criteria Manual; restore floodplain health, or provide mitigation if restoration is infeasible, to support natural functions and processes as prescribed in the floodplain modification criteria in the Environmental Criteria Manual; and comply with the requirements of Chapter 25-7 (Drainage), the Drainage Criteria Manual, and the Environmental Criteria Manual. (3) (4) (D) If mitigation is required under this Section, it may be satisfied by: (1) paying into the Riparian Zone Mitigation Fund a nonrefundable amount established by ordinance; transferring in fee simple or placing restrictions on mitigation land approved by the director of the (2) Watershed Protection Department and meeting the following conditions: (a) (b) (c) (d) located within the same watershed classification; in accordance with the procedures in Section 25-8-26 (Redevelopment Exception in the Barton Springs Zone), Subsection (H) (3); dedicated to or restricted for the benefit of the City or another entity approved by the Watershed Protection Department director and which the City or other approved entity accepts; an amount proportionate to the amount of area within the existing floodplain that is proposed to be modified, as prescribed in the Environmental Criteria Manual; or (3) a combination of the mitigation methods described in Subparagraphs (1) and (2), if approved by the director of the Watershed Protection Department. Division 7. Shoreline Relocation and Lakefill. § 25-8-367 RELOCATION OF SHORELINE BETWEEN TOM MILLER DAM AND LONGHORN DAM. (A) This section applies: along the Colorado River; (1) (2) between Tom Miller Dam and Longhorn Dam; and (3) below a contour elevation of 435 feet above mean sea level. (B) City council approval is required to relocate existing earth material in the area described in Subsection (A). (C) A person may request approval under this section by filing an application with the council that includes a plan showing the proposed layout of the relocation and a legal description of the property. (D) The applicant must demonstrate to the council that: (1) approving the application will not: (a) (b) endanger a water supply, water supply system, storm or sanitary sewer facility, or other public utility facility; create a hazard to navigation or swimming; 33 (c) create a hazard to the safety, maintenance and operation of a dam, bridge, or other structure not owned by the applicant; and (d) materially and adversely affect the use and enjoyment of other property on the Colorado River between the Tom Miller Dam and Longhorn Dam; and (2) if similar applications were granted for all similarly situated properties, the water storage or flood capacity of the Colorado River basin would not be materially reduced. § 25-8-368 RESTRICTIONS ON DEVELOPMENT IMPACTING LAKE AUSTIN, LADY BIRD LAKE, AND LAKE WALTER E. LONG. Lake Walter E. Long. (A) The requirements of this section apply to development on or adjacent to Lake Austin, Lady Bird Lake, or (B) Except as otherwise provided by this section, placing fill or dredging in a lake is prohibited. (C) A retaining wall, bulkhead, or other erosion protection device may not capture or recapture land from a lake unless doing so is required to restore the shoreline to whichever of the following boundaries would encroach the least into the lake: (1) (2) the shoreline as it existed 10 years prior to the date of application, with documentation as prescribed by the Environmental Criteria Manual; or the lakeside boundary of the subdivided lot line. (D) A bulkhead may be replaced in front of an existing bulkhead once, if: (1) (2) (3) the existing bulkhead was legally constructed; and construction of the replacement bulkhead does not change the location of the shoreline by more than 6 inches; and the director of the Watershed Protection Department determines that there is no reasonable alternative to replacement of the bulkhead in the location of the existing bulkhead. (E) The director may approve less than 25 cubic yards of dredging in a lake if the dredging is necessary for navigation safety. CHAPTER 25-8 SUBCHAPTER B. ARTICLE 2. ENDANGERED SPECIES.Threatened or Endangered Species Notification § 25-8-691 THREATENED OR ENDANGERED SPECIES NOTIFICATIONAPPLICABILITY. (A) This section applies in areas of the planning jurisdiction that may contain habitat for federally listed threatened or endangered species identified in the map maintained by the City online or available for inspection in the office of the Development Services Department. Except as provided in Subsection (B), this article applies to development in the areas of the planning jurisdiction described in Sections 25-8-693 (Birds And Plants), 25-8-694 (Cave Species), and 25-8-695 (Salamander Species). (B) On submission of an application for a subdivision or site plan in an area described in Subsection (A), the applicant must give notice of the application to the appropriate authority, including: (1) United States Fish and Wildlife Service; (2) Balcones Canyonlands Conservation Plan Coordinating Committee Secretary; and (3) Travis or Williamson County, as applicable depending on project location. (C) The notice must include a statement that the development could cause the loss of threatened or endangered species habitat. This article does not apply to development of: (1) (2) (3) a subdivision for which a preliminary plan or final plat was approved before August 27, 1989; a site for which a site plan or site development permit was approved before August 27, 1989; or a tract of land containing not more than ten acres, if the tract: (a) is legally platted; or 34 (b) existed in its current configuration when it became subject to City subdivision regulations. black-capped vireo; golden-cheeked warbler; Tooth Cave pseudoscorpion; Tooth Cave spider; Bee Creek Cave harvestman; Tooth Cave ground beetle; Kretschmarr Cave mold beetle; Jollyville Plateau salamander; a species included in the Balcones Canyonland Conservation Plan; or a species classified as threatened or endangered by the United States Fish and Wildlife Service. § 25-8-692 THREATENED OR ENDANGERED SPECIES. In this article, "threatened or endangered species" means: (1) (2) (3) (4) (5) (6) (7) (8) (9) (10) Source: Section 13-7-73; Ord. 990225-70; Ord. 031211-11; Ord. No. 20170615-102 , Pt. 30, 6-15-17. § 25-8-693 BIRDS AND PLANTS. For an endangered bird or plant species, the requirements of Section 25-8-696 (Notice) apply west of a line bounded by U. S. 183 North at the City's extraterritorial boundary limit, then southeast to Loop 1, then south along Loop 1 to U.S. 290 West, then west on U. S. 290 to R.M. 1826, and then south to the City's extraterritorial boundary limit. Source: Section 13-7-72(a)(1), and (b); Ord. 990225-70; Ord. 031211-11; Ord. 20131017-046. § 25-8-694 CAVE SPECIES. For an endangered cave species, the requirements of Section 25-8-696 (Notice) apply in the Edwards Aquifer Recharge Zone as defined by Section 25-8-2 (Description of Regulated Areas). Source: Section 13-7-72(a)(2) and (b); Ord. 990225-70; Ord. 031211-11; Ord. 20131017-046. § 25-8-695 SALAMANDER SPECIES. For a threatened or endangered salamander species, the requirements of Section 25-8-696 (Notice) apply in the areas included in the salamander habitat map maintained by the Watershed Protection Department. Source: Ord. 20131017-046; Ord. No. 20170615-102 , Pt. 31, 6-15-17. § 25-8-696 NOTICE. (A) On submission of an application for subdivision or site plan approval in an area described in Section 25-8- 693 (Birds and Plants), 25-8-694 (Cave Species), or 25-8-695 (Salamander Species)Subsection (A), the applicant shall give notice of the application to the appropriate authority, including: Texas Parks and Wildlife Department; (1) United States Fish and Wildlife Service; (2) (3) Balcones Canyonlands Conservation Plan Coordinating Committee Secretary; and (4) Travis or Williamson County, as applicable. (B) The notice must include a statement that the development could cause the loss of threatened or endangered species habitat. 35