B-09 CORRECTED (SP-2021-0021D - 3800 Island Way; District 10).pdf — original pdf

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SITE PLAN REVIEW SHEET ENVIRONMENTAL VARIANCE REQUEST ONLY PLANNING COMMISSION DATE: July 20th, 2021 CASE: SP-2021-0021D PROJECT NAME: 3800 Island Way APPLICANT: Chris Hester AGENT: Janis Smith Consulting, LLC (Janis Smith, PE) ADDRESS OF SITE: 3800 Island Way COUNTY: Travis WATERSHED: Lake Austin JURISDICTION: Full Purpose EXISTING ZONING: LA, SF-3 PROPOSED DEVELOPMENT: The applicant is proposing to construct a boat dock. DESCRIPTION OF VARIANCES: The applicant is requesting to vary from LDC 25-8-281(C)(2)(b) to allow construction of a boat dock within a 150-foot Critical Environmental Feature (CEF). STAFF RECOMMENDATION: The findings of fact have been met, and staff recommends approval for construction within a 150 foot Critical Environmental Feature (CEF) with the following conditions: 1) All construction activities to be completed by barge. AREA: .5 acres ENVIRONMENTAL BOARD ACTION: July 7th, 2021: With a 8-0 vote, the Environmental Commission recommends support of the request for a variance from LDC 25-8-281(C)(2)(b) with the following conditions; 1) All construction activities to be completed by barge. WATERSHED PROTECTION STAFF: Eric Brown PHONE: 978-1539 Eric.Brown@austintexas.gov CASE MANAGER: Clarissa Davis Clarissa.Davis@austintexas.gov PHONE: 974-1423 B-091 of 53ITEM FOR DEVELOPMENT COMMITTEE MEETING MEETING DATE: NAME & NUMBER OF PROJECT: June 16, 2021 3800 Island Way SP-2021-0021D NAME OF APPLICANT OR ORGANIZATION: Janis Smith, PE Janis Smith Consulting, LLC LOCATION: 3800 Island Way Austin, Texas 78746 COUNCIL DISTRICT: Council District #10 ENVIRONMENTAL REVIEW STAFF Eric Brown Senior Environmental Scientist Watershed Protection Department Eric.Brown@austintexas.gov WATERSHED: Lake Austin Watershed, Water Supply Rural Classification, Drinking Water Protection Zone REQUEST: STAFF RECOMMENDATION: RECOMMENDED CONDITIONS: Request to vary from LDC 25-8-281(C)(2)(B) to allow construction within 150-feet of Critical Environmental Feature (Rimrock) Staff recommends this variance having determined the findings of facts have been met. 1. Construction to be completed by barge. B-092 of 53Staff Findings of Fact B-093 of 533800 ISLAND WAY– BOAT DOCK REPLACEMENT SP- 2021-0021D Eric Brown Hydrogeologic Reviewer Watershed Protection Department B-094 of 53B-095 of 53PROPERTY DATA • LAKE AUSTIN WATERSHED • WATER SUPPLY RURAL CLASSIFICATION • CRITICAL ENVIRONMENTAL FEATURES ON SITE • COUNCIL DISTRICT 10 B-096 of 53B-097 of 53B-098 of 53BACKGROUND • • • • BOAT DOCK ON THE LAKE NEAR RIMROCK BRINGING EXISTING NON-COMPLIANT DOCK INTO COMPLIANCE ADDING SECOND STORY B-099 of 53CODE REFERENCE •TITLE 25 – LAND DEVELOPMENT CODE, CHAPTER 25-8-281(C)(2)(B). B-0910 of 53VARIANCE REQUEST REQUEST TO VARY FROM LDC 25-8- 281(C)(2)(B) TO ALLOW CONSTRUCTION WITHIN 150-FOOT OF CRITICAL ENVIRONMENTAL FEATURE (CEF) BUFFERS. B-0911 of 53Rimrock CEF B-0912 of 53B-0913 of 53VARIANCE RECOMMENDATION FINDING OF FACTS HAVE BEEN MET. STAFF RECOMMENDS THE APPROVAL OF THIS VARIANCE WITH THE CONDITION THAT ALL CONSTRUCTION BE COMPLETED BY BARGE. B-0914 of 53QUESTIONS? B-0915 of 53 Watershed Protection Department Staff Recommendations Concerning Required Findings Project Name & Case Number: 3800 ISLAND WAY Boat Dock Replacement SP- 2021-0021D Ordinance Standard: Watershed Protection Ordinance Variance Request: LDC 25-8-281(C)(2)(b) - To allow construction within 150 feet of a Rimrock Critical Environmental Features (CEF) Include an explanation with each applicable finding of fact. A. Land Use Commission variance determinations from Chapter 25-8-41 of the City Code: 1. The requirement will deprive the applicant of a privilege available to owners of similarly situated property with approximately contemporaneous development subject to similar code requirements. Yes. A variance from 25-8-281(C)(2)(b) allowing for construction of a boat dock, shoreline access, and stabilization, has been granted for similarly situated properties with approximately contemporaneous development subject to similar code. 2. The variance: a) Is not necessitated by the scale, layout, construction method, or other design decision made by the applicant, unless the design decision provides greater overall environmental protection than is achievable without the variance; Yes. No disturbance of the rimrock CEF is proposed, all proposed construction activities are to occur downgradient of the rimrock CEFs, and construction is to occur from the lakeside by barge. The proposed construction to be performed from a barge provides greater overall environmental protection. Additionally, the applicant is providing wetland plantings that will reduce shoreline erosion and sediment-laden surface runoff from discharging into the lake. b) Is the minimum deviation from the code requirement necessary to allow a reasonable use of the property; B-0916 of 53 Yes. The variance is the minimum deviation from the code requirement to allow for a reasonable use of the property. The code requires a 150-foot critical environmental feature buffer. This buffer is not being reduced. The scope of the variance is limited to allowing construction activities to occur within a critical environmental feature buffer temporarily and only for the proposed boat dock replacement. c) Does not create a significant probability of harmful environmental consequences. Yes. The variance does not create significant harmful environmental consequences. The construction of the boat dock from barge will not disturb the rimrock critical environmental feature. The applicant is providing wetland plantings that will reduce erosion and sediment-laden surface runoff from discharging into the lake. 3. Development with the variance will result in water quality that is at least equal to the water quality achievable without the variance. Yes, the variance will result in water quality that is at least equal to the water quality achievable without the variance. The construction activities will not disturb the rimrock critical environmental features. The proposed wetland planting along the shoreline will reduce soil erosion along the shoreline and provide filtration of sediment-laden runoff from upgradient areas, thereby providing water quality that is at least equal to or greater than the water quality achievable without the variance. Staff Recommendation: Staff recommends the variance as the Findings of Fact have been met, with the staff recommended condition that all construction be completed by barge. B. The Land Use Commission may grant a variance from a requirement of Section 25-8- 422 (Water Supply Suburban Water Quality Transition Zone), Section 25-8-452 (Water Supply Rural Water Quality Transition Zone), Section 25-8-482 (Barton Springs Zone Water Quality Transition Zone), Section 25-8-368 (Restrictions on Development Impacting Lake Austin, Lady Bird Lake, and Lake Walter E. Long), or Article 7, Division 1 ( Critical Water Quality Zone Restrictions ), after determining that: The criteria for granting a variance in Subsection (A) are met; Yes / No N/A Yes / No N/A The requirement for which a variance is requested prevents a reasonable, economic use of the entire property; 3. The variance is the minimum deviation from the code requirement necessary to allow a reasonable, economic use of the entire property. Yes / No N/A Staff Recommendation: N/A. 1. 2. B-0917 of 53___________________________ Eric Brown Date: 06-02-2021 Deputy Environmental Officer (WPD) Liz Johnston Date: 06-02-2021 Hydrogeologic Reviewer (WPD) B-0918 of 53Applicant Form and Findings of Fact B-0919 of 53March 22, 2021 ENVIRONMENTAL COMMISSION VARIANCE APPLICATION FORM PROJECT DESCRIPTION Applicant Contact Information Name of Applicant Street Address City State ZIP Code Work Phone E-Mail Address Case Name Case Number Variance Case Information Chris Hester 3800B Island Cove Austin, TX 78746 512-692-7175 chris.hester@cttlp.com 3800 Island Cove SP-2021-0021D 3800 Island Cove Pamela Abee-Taulli Address or Location Environmental Reviewer Name Environmental Resource Management Reviewer Name Applicable Ordinance LDC 25-8-281(C)(2)(b) Watershed Name Lake Austin Watershed Classification ☐Urban ☐ Suburban X Water Supply Suburban ☐Water Supply Rural ☐ Barton Springs Zone City of Austin | Environmental Commission Variance Application Guide 1 B-0920 of 53Edwards Aquifer Recharge Zone X Barton Springs Segment ☐ Northern Edwards Segment ☐ Not in Edwards Aquifer Zones Edwards Aquifer Contributing Zone Distance to Nearest Classified Waterway Water and Waste Water service to be provided by NA ☐ Yes X No The boat dock is in Lake Austin. Request The variance request is as follows (Cite code references: To allow construction in a rimrock CEF buffer. Existing ________ ________ ________ Proposed _________ _________ _________ 3800 Island Cove is a 0.6 acre duplex homesite on the shoreline of Lake Austin. Two-thirds of the site is in the lake underwater. Attachment 1 contains an aerial photo of the site. It’s located about two miles northwest of the intersection of Westlake Drive and Redbud Trail. The site contains a duplex, grandfathered dock and access, and two rimrocks which border the existing home. It was originally developed in the 80s as part of a development featuring five duplex homesites, four of which are lakefront. The existing dock moors three boats and is oriented parallel to the shoreline as was common in the 80s. On this very busy portion of the lake, boat traffic is heavy with the associated high energy wave action. The orientation of the dock makes it perilous to get into and out of the boats as waves roll underneath. This project proposes to reconstruct the dock with two slips oriented perpendicular to the shoreline so that it’s safe to get into and out of the boats. March 22, 2021 Impervious cover square footage: acreage: percentage: Provide general description of the property (slope range, elevation range, summary of vegetation / trees, summary of the geology, CWQZ, WQTZ, CEFs, floodplain, heritage trees, any other notable or outstanding characteristics of the property) City of Austin | Environmental Commission Variance Application Guide 2 B-0921 of 53March 22, 2021 Project: Ordinance: A. 1. 2. Clearly indicate in what way the proposed project does not comply with current Code (include maps and exhibits) This project proposes to demolish an existing, grandfathered, dock and construct a new dock in the same location but oriented perpendicular to the shoreline. The existing and proposed dock location is about 120 LF from the nearest rimrock CEF and falls within the 150 ft. CEF setback required by Code. Please see Attachment 2 for the Proposed Conditions Site Plan Sheet. Attachment 3 contains the Environmental Resource Inventory. FINDINGS OF FACT As required in LDC Section 25-8-41, in order to grant a variance the Land Use Commission must make the following findings of fact: Include an explanation with each applicable finding of fact. Land Use Commission variance determinations from Chapter 25-8-41 of the City Code: The requirement will deprive the applicant of a privilege available to owners of similarly situated property with approximately contemporaneous development subject to similar code requirements. Yes / No Please see Attachment 4, Basis of Determination. The variance: a) Is not necessitated by the scale, layout, construction method, or other design decision made by the applicant, unless the design decision provides greater overall environmental protection than is achievable without the variance; b) c) Yes / No Please see Attachment 4, Basis of Determination. Is the minimum deviation from the code requirement necessary to allow a reasonable use of the property; Yes / No Please see Attachment 4, Basis of Determination. Does not create a significant probability of harmful environmental consequences. Yes / No Please see Attachment 4, Basis of Determination. City of Austin | Environmental Commission Variance Application Guide 3 B-0922 of 53March 22, 2021 Development with the variance will result in water quality that is at least equal to the water quality achievable without the variance. Yes / No Please see Attachment 4, Basis of Determination. B. Additional Land Use Commission variance determinations for a requirement of Section 25-8-422 (Water Quality Transition Zone), Section 25-8-452 (Water Quality Transition Zone), Article 7, Division 1 (Critical Water Quality Zone Restrictions), or Section 25-8-368 (Restrictions on Development Impacting Lake Austin, Lady Bird Lake, and Lake Walter E. Long): 1. The criteria for granting a variance in Subsection (A) are met; Not Applicable Yes / No [provide summary of justification for determination] The requirement for which a variance is requested prevents a reasonable, economic use of the entire property; Yes / No [provide summary of justification for determination] The variance is the minimum deviation from the code requirement necessary to allow a reasonable, economic use of the entire property. Yes / No [provide summary of justification for determination] 3. 2. 3. **Variance approval requires all above affirmative findings. City of Austin | Environmental Commission Variance Application Guide 4 B-0923 of 53March 22, 2021 A Exhibits for Commission Variance o Aerial photos of the site o Site photos o Aerial photos of the vicinity o Context Map—A map illustrating the subject property in relation to developments in the vicinity to include nearby major streets and waterways o Topographic Map - A topographic map is recommended if a significant grade change on the subject site exists or if there is a significant difference in grade in relation to adjacent properties. o For cut/fill variances, a plan sheet showing areas and depth of cut/fill with topographic elevations. o Site plan showing existing conditions if development exists currently on the property o Proposed Site Plan- full size electronic or at least legible 11x17 showing proposed development, include tree survey if required as part of site or subdivision plan o Environmental Map – A map that shows pertinent features including Floodplain, CWQZ, WQTZ, CEFs, Setbacks, Recharge Zone, etc. o An Environmental Resource Inventory pursuant to ECM 1.3.0 (if required by 25-8-121) o Applicant’s variance request letter City of Austin | Environmental Commission Variance Application Guide 5 B-0924 of 53March 22, 2021 ATTACHMENT 1 AERIAL SITE PHOTO City of Austin | Environmental Commission Variance Application Guide 6 B-0925 of 53B-0926 of 53March 22, 2021 ATTACHMENT 2 PROPOSED CONDITIONS SITE PLAN SHEET City of Austin | Environmental Commission Variance Application Guide 7 B-0927 of 533800 ISLAND WAY TOTAL APPENDIX F TREE INCHES SURVEYED: 36.0 TOTAL APPENDIX F TREE INCHES REMOVED: 0.0 TOTAL NON-APPENDIX F AND INVASIVE REMOVED: 0.0 0.0 TOTAL MITIGATION INCHES PLANTED ON-SITE TOTAL DEAD INCHES REMOVED: 0.0 TOTAL NON-MITIGATION INCHES PLANTED ON-SITE 4.0 PLANTING MITIGATION CALCULATIONS 609S RESTORATION · ALL DISTURBED AREAS WITHIN THE SHORELINE SETBACK SHALL BE REVEGETATED PURSUANT TO 609S SPECIFICATIONS, USING 609S SEEDING OR PLANTING AREA OF IMPACT IS APPROXIMATELY 79 SF PLANTING CRITERIA RECOMMENDS 1 NATIVE SHADE TREE AND 1 NATIVE UNDERSTORY TREE/500 SF OF DISTURBED AREA 79 SF/500 SF = 1 SHADE TREE AND 1 UNDERSTORY TREE AND 1 NATIVE SHRUB/100 SF 79 SF/100 = 1 SHRUBS WETLAND MITIGATION · PLANTING MITIGATION NOTES 24 SF AT 2 FT CENTERS IN A TRIANGULAR PATTERN YIELDS 7 PLANTS. ALL PLANTS TO BE SOURCED WITHIN A 200 MILE RADIUS OF AUSTIN. FOLLOW ALL GUIDELINES FOUND IN THE CITY OF AUSTIN ENVIRONMENTAL CRITERIA MANUAL, REFERENCE CODE SECTIONS ECM 1.13.0, ECM 1.10.4(D), & ITEM NO. 609S AS APPLICABLE ALL PLANTS TO BE INSTALLED AT A MAXIMUM OF 3FT ON CENTERS. · · · · · · SHORELINE MITIGATION PLANTING SCHEDULE NUMBER OF PLANTS TYPE OF MITIGATION PLANT NAME Bald Cypress (Taxodium distichum)** Mexican Plum (Prunus mexicana)** White Mistflower (Ageratina havanensis)^ Blue Flag Iris (Iris fulva or virginica) Big Muhly (Muhlenbergia lindheimeri) Cardinal flower (Lobelia cardinalis) 1 1 1 2 2 3 TOTAL = 10 PLANTS Floodplain Floodplain Floodplain Wetland Wetland Wetland 2" caliper trees Native shrub with low water needs ** ^ Alternative native and adapted species may be substituted with the same quantity of another species and plant planting location maybe modified as approved by the PDR Environmental reviewer, ERM Wetland Biologist or ERM Landscape Architect. TOTAL 609S SHRUBS REQUIRED = 1 SHRUB. 1 SHRUB IS PROPOSED TOTAL 609S UNDERSTORY TREES REQUIRED = 1 TREE. 1 UNDERSTORY TREE IS PROPOSED TOTAL 609S SHADE TREES REQUIRED = 1 TREE. 1 SHADE TREE IS PROPOSED TOTAL 609S PLANTS REQUIRED = 3 PLANTS. 3 PLANTS PROPOSED WETLAND PLANTS REQUIRED = 7 PLANTS. 8 PLANTS PROPOSED EXISTING = PROPOSED ACCESS 9.5' 30.0' 25.0' EXISTING SHORELINE LENGTH = 41.6' ALLOWABLE DOCK WIDTH = 23.6' (GRANDFATHERED STRUCTURES) PROPOSED DOCK WIDTH = 22.0' PROPOSED DOCK DEPTH = 35.8' DOCK FOOTPRINT = 658.7 SF X X X X X X X X 75' CWQZ SETBACK X X X X X X X X X X X X X X X X X X X X X X X X X X 38.7' C O L F S S C O L F S S C O L F S S C O L F S S C O L C O L F S S C O L F S S C O L F S S C O L F S S C O L F S S C O L C O L C O L 4 9 1 THE PORTION OF THE LIMITS OF CONSTRUCTION ON THE SHORE LIES IN THE CWQZ. THIS AREA REQUIRES NATIVE GRASSLAND SEEDING AND PLANTING PER CITY OF AUSTIN STANDARD SPECIFICATION 6095.6, INCLUDING TOPSOIL AND SEED BED PREPARATION, TEMPORARY IRRIGATION, AND WEED MAINTENANCE 495 X X FEMA 100-YR FULLY DEVELOPED FLOODPLAIN/BFE ELEV = 492.9' PROPERTY IS IN THE IS FULL PURPOSE JURISDICTION OF THE CITY OF AUSTIN EXISTING = PROPOSED DOCK ACCESS REPAIR AS NEEDED INSTALL TREE BOARDS BIG MUHLY 494 4 9 LOC 3 LOC X X LOC X X XX LOC L O C LOC LOC MEXICAN PLUM WHITE MISTFLOWER BALD CYPRESS LOC L O C L O C LOC C O L C O L C O L TREE CRZ TREE 1 2 CRZ TREE 1 4 CRZ LOC F S S L O C L O C F S S F S S F S S L O C L O C L O C L O C L O C F S S F S S L O C F S S L O C L O C L O C L O C 2 9 4 490 IRIS AND CARDINAL FLOWER EXISTING = PROPOSED SHORELINE ELEV = 492.8' 4 8 9 30.0' RIMROCK 2 CRITICAL ENVIRONMENTAL FEATURE SETBACK L O C F S S RIMROCK 1 CRITICAL ENVIRONMENTAL FEATURE SETBACK 4 8 8 PROPOSED 2-SLIP DOCK 22.0' x 30.0', AREA = 658.0 SF NO DREDGING PROPOSED SEE DOCK PLAN/ELEV VIEWS THIS SHEET L O C F S S F S S LEGEND EXISTING = PROPOSED SHORELINE FEMA 100-YR FLOODPLAIN/BFE CWQZ SETBACK GRANDFATHER FOOTPRINT TREE PROTECTION FLOATING SILT SCREEN LIMIT OF CONSTRUCTION PROPOSED DOCK TREE CRITICAL ROOT ZONE, 1 AND 1 4 CRZ 2 CRZ, XX FSS LOC XX FSS LOC TREE # 6.7' C O L 4.2' F S S GRANDFATHER FOOTPRINT FOOTPRINT SHOWN IN 1984 AND STILL IN USE AREA = 673.9 SF 22.00 FIRST FLOOR PLAN VIEW 1" = 10' SECOND FLOOR PLAN VIEW 1" = 10' 20 10 0 20 40 FSS FSS FSS FSS 23.6' FSS FSS FSS SCALE: 1" = 20' INSTALL FLOATING SILT SCREEN APPROX. 130.4 LF LIMITS OF CONSTRUCTION LOC LOC LOC LOC LOC LOC LOC LOC EXISTING = PROPOSED ACCESS GRANDFATHERED HORIZONTAL AND VERTICAL FOOTPRINT SEE SHEET 4 FOR EXISTING PLAN/ELEVATION VIEWS NAVIGATION LIGHTS EL. 509.3' EL. 505.8' EL. = 494.8' EXISTING = PROPOSED BULKHEAD T.O.W. = 493.8' OPEN OPEN OPEN OPEN DOCK EL. = 494.8' APPROX. WSEL = 492.8' BOTTOM OF BEAM ELEV = 493.8' SIDE ELEVATION 1" = 10' LAKESIDE ELEVATION 1" = 10' PROPOSED CONDITIONS PROPOSED PLAN/ELEVATION VIEWS NOTE: THE PROPOSED BOAT DOCK MUST COMPLY WITH ALL REQUIREMENTS OF LDC 25-2-1174 (“STRUCTURAL REQUIREMENTS”), AND MUST COMPLY WITH CHAPTER 25-12, ARTICLE 1 (UNIFORM BUILDING CODE) AND THE BUILDING CRITERIA MANUAL. NOTES: 1. ALL WORK SHALL OCCUR WITHIN THE LIMITS OF CONSTRUCTION AS SHOWN ON THE PLAN. ALL MATERIALS WILL BE TRANSPORTED TO THE SITE FROM WATER. ALL CONSTRUCTION ACTIVITY, INCLUDING STAGING AND SPOIL STORAGE, WILL BE COMPLETED BY WATER. 2. SHORELINE IMPROVEMENTS, INCLUDING GANGWAY ACCESS, ARE AUTHORIZED WITH THIS SITE PLAN. 3. CONTAINERS OF HAZARDOUS MATERIALS, FUEL, OIL, HERBICIDES, INSECTICIDES, 4. FERTILIZERS, OR OTHER POLLUTANTS WILL NOT BE STORED ON DOCKS EXTENDING INTO OR ABOVE LAKE AUSTIN. FOR LA ZONING, PERMANENT IMPROVEMENTS ARE PROHIBITED WITHIN THE SHORELINE SETBACK AREA, EXCEPT FOR RETAINING WALLS, PIERS, WHARVES, BOATHOUSES, MARINAS, OR A DRIVE TO ACCESS THE STRUCTURES [LDC 25-2-551 (B)(2)]. 5. NO WATER OR WASTEWATER UTILITIES ARE PROPOSED WITH THIS DEVELOPMENT. 6. DOCK SHALL BE AT LEAST 66% OPEN. 7. PILINGS SHALL BE 6-5/8" DIAMETER STEEL PIPE. 8. THE PROJECT SITE IS WITHIN THE CITY OF AUSTIN FULL PURPOSE BOUNDARIES. ATTENTION INSPECTOR NOTES: 1. COMPLIANCE WITH BUILDING CODE REQUIRED AND IS TO BE REVIEWED FOR 2. COMPLIANCE DURING BUILDING CODE REVIEW. FOR THE BUILDING PERMIT, A SIGNED AND SEALED LETTER SHALL BE SUBMITTED TO THE CITY OF AUSTIN, PER THE LAND DEVELOPMENT CODE, 25-12-3 1612.4, CERTIFYING THAT THE STRUCTURE IS IN ACCORDANCE WITH ASCE 24, FLOOD RESISTANT DESIGN AND CONSTRUCTION. 3. ENVIRONMENTAL INSPECTOR HAS THE AUTHORITY TO ADD AND/OR MODIFY EROSION/SEDIMENTATION CONTROLS ON SITE TO KEEP PROJECT IN COMPLIANCE WITH THE CITY OF AUSTIN RULES AND REGULATIONS. ' D V P P A I N O S V E R I E T A D . O N 1 2 0 2 / 3 2 / 3 0 9 2 7 3 - 4 1 9 - 2 1 5 3 0 7 8 7 s a x e T , n i t s u A d a o R r e v o t s e W 5 0 5 1 8 7 9 6 1 - F r e b m u N n o i t a r t s i g e R s r e e n i g n E l a n o i s s e f o r P f o d r a o B s a x e T C L L , g n i t l u s n o C h t i m S s i n a J Y A W D N A L S I 0 0 8 3 I I I N A L P E T S S N O T D N O C D E S O P O R P D 1 2 0 0 - 1 2 0 2 - P S - Y A W D N A L S I 0 0 8 3 DESIGNED: JJS APPROVED: SCALE: AS SHOWN 3800 ISLAND WAY DATE: JANUARY 11, 2021 SHEET of 5 3 3 SP-2021-0021D B-0928 of 53March 22, 2021 ATTACHMENT 3 ENVIRONMENTAL RESOURCE INVENTORY City of Austin | Environmental Commission Variance Application Guide 9 B-0929 of 53City of Austin – Environmental Resource Inventory (ERI) 3800 Island Way Travis County, Texas November 16, 2020, revised March 22, 2021 By: DESCO Environmental Consultants, LP 26902 Nichols Sawmill Road Magnolia, Texas 77355 B-0930 of 53Case No.: (City use only) Environmental Resource Inventory For the City of Austin Related to LDC 25-8-121, City Code 30-5-121, ECM 1.3.0 & 1.10.0 The ERI is required for projects that meet one or more of the criteria listed in LDC 25-8-121(A), City Code 30-5-121(A). 1. SITE/PROJECT NAME: 3800 Island Way - Lot E 2. COUNTY APPRAISAL DISTRICT PROPERTY ID (#’s): 541296 3800 Island Way, Lot E, Austin, TX 78746 3. ADDRESS/LOCATION OF PROJECT: 4. WATERSHED: Austin-Travis Lakes 5. THIS SITE IS WITHIN THE (Check all that apply) Edwards Aquifer Recharge Zone* (See note below) .................. (cid:133)YES (cid:133)No Edwards Aquifer Contributing Zone*.................................. (cid:133)YES (cid:133)No Edwards Aquifer 1500 ft Verification Zone* ....................... (cid:133)YES (cid:133)No Barton Spring Zone* .......................................................... (cid:133)YES (cid:133)No *(as defined by the City of Austin – LDC 25-8-2 or City Code 30-5-2) ✔ ✔ ✔ ✔ Note: If the property is over the Edwards Aquifer Recharge zone, the Hydrogeologic Report and karst surveys must be completed and signed by a Professional Geoscientist Licensed in the State of Texas. 6. DOES THIS PROJECT PROPOSE FLOODPLAIN MODIFICATION?.......(cid:133) YES** (cid:133)NO x If yes, then check all that apply: (cid:13)(1) The floodplain modifications proposed are necessary to protect the public health and safety; (cid:13) (2) The floodplain modifications proposed would provide a significant, demonstrable environmental benefit, as determined by a functional assessment of floodplain health as prescribed by the Environmental Criteria Manual (ECM), or (cid:13) (3) The floodplain modifications proposed are necessary for development allowed in the critical water quality zone under LDC 25-8-261 or 25-8-262, City Code 30-5-261 or 30-5-262. (cid:13) (4) The floodplain modifications proposed are outside of the Critical Water Quality Zone in an area determined to be in poor or fair condition by a functional assessment of floodplain health. ** If yes, then a functional assessment must be completed and attached to the ERI (see ECM 1.7 and Appendix X for forms and guidance) unless conditions 1 or 3 above apply. 7. IF THE SITE IS WITHIN AN URBAN OR SUBURBAN WATERSHED, DOES THIS PROJECT PROPOSE A UTILITY LINE PARALLEL TO AND WITHIN THE CRITICAL WATER QUALITY ZONE? ......................................................... (cid:133)YES*** (cid:133)NO ✔ ***If yes, then riparian restoration is required by LDC 25-8-261(E) or City Code 30-5-261(E) and a functional assessment must be completed and attached to the ERI (see ECM1.5 and Appendix X for forms and guidance). 3 8. There is a total of (#’s) Critical Environmental Feature(s)(CEFs) on or within150 feet of the project site. If CEF(s) are present, attach a detailed DESCRIPTION of the CEF(s), color PHOTOGRAPHS, the CEF WORKSHEET and provide DESCRIPTIONS of the proposed CEF buffer(s) and/or wetland mitigation. Provide the number of each type of CEFs on or within 150 feet of the site (Please provide the number of CEFs ): B-0931 of 530 2 (#’s) Spring(s)/Seep(s) (#’s) Canyon Rimrock(s) 0 (#’s) Point Recharge Feature(s) 1 (#’s) Wetland(s) 0 (#’s) Bluff(s) Note: Standard buffers for CEFs are 150 feet, with a maximum of 300 feet for point recharge features. Except for wetlands, if the standard buffer is not provided, you must provide a written request for an administrative variance from LDC 25-8-281(C)(1) and provide written findings of fact to support your request. Request forms for administrative variances from requirements stated in LDC 25-8-281 are available from Watershed Protection Department. 9. The following site maps are attached at the end of this report (Check all that apply and provide): All ERI reports must include: (cid:13) Site Specific Geologic Map with 2-ft Topography x (cid:13) Historic Aerial Photo of the Site x (cid:13) Site Soil Map x (cid:13) Critical Environmental Features and Well Location Map on current x Aerial Photo with 2-ft Topography Only if present on site (Maps can be combined): (cid:13) Edwards Aquifer Recharge Zone with the 1500-ft Verification Zone(cid:3) x (cid:3) (cid:3) (Only if site is over or within 1500 feet the recharge zone) (cid:13) Edwards Aquifer Contributing Zone(cid:3) (cid:13) Water Quality Transition Zone (WQTZ) (cid:13) Critical Water Quality Zone (CWQZ)(cid:3) x (cid:13) City of Austin Fully Developed Floodplains for all water courses with x (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) (cid:3) up to 64-acres of drainage 10. HYDROGEOLOGIC REPORT – Provide a description of site soils, topography, and site specific geology below (Attach additional sheets if needed): Surface Soils on the project site is summarized in the table below and uses the SCS Hydrologic Soil Groups*. If there is more than one soil unit on the project site, show each soil unit on the site soils map. Soil Series Unit Names, Infiltration Characteristics & Thickness *Soil Hydrologic Groups Definitions (Abbreviated) Soil Series Unit Name & Subgroup** Group* Thickness (feet) Eckrant soils and Urban land, 5 to 18 percent slopes Eckrant soils and Urban land, 18 to 40 percent slopes D D 1 1 A. Soils having a high infiltration rate when thoroughly wetted. B. Soils having a moderate infiltration rate when thoroughly wetted. C. Soils having a slow infiltration rate when thoroughly wetted. D. Soils having a very slow infiltration rate when thoroughly wetted. **Subgroup Classification – See Classification of Soil Series Table in County Soil Survey. WPD ERM ERI-2014-01 Page 2 of 6 B-0932 of 53Description of Site Topography and Drainage (Attach additional sheets if needed): As verified from the City of Austin GIS, two rimrocks are present on the far northwestern portion of the property (Figure 4). Rimrock 1 averages approximately 25 feet tall and Rimrock 2 averages approximately 12 feet tall. At the bottom of Rimrock 1, the property is very gently sloped from northwest to southeast towards Lake Austin (Colorado River) in the Austin-Travis Lake watershed, downstream of Lake Travis. The average slope of the property at the bottom of the rimrocks is approximately 1%. Island Way borders the property to the northeast and similar properties border the property to the north, east, and west. A main residence with covered parking and two story boat slips are located on the property. A rock retaining wall is installed along the entire shoreline which extends 2' above the water line. One wetland (wetland 1) was identified by City of Austin staff adjacent to the boat dock consisting of landscaped umbrella sedge (Cyperus involucratus). Other than the two rimrocks and one wetland, no additional CEFs were observed on or adjacent to the property. List surface geologic units below: Group Trinity Geologic Units Exposed at Surface Formation Glen Rose Formation Comanche Peak Fredericksburg Group Member Cretaceous Comanchean Brief description of site geology (Attach additional sheets if needed): Glen Rose Formation - Limestone, dolomite, and marl in alternating resistant and recessive beds forming stair step topography;limestone, alphantic to fine grained, hard to soft and marly, light grey to yellowish grey; dolomite, fine grained, porous, yellowish brown; marine megafossils include steinkems, rudistids oysters, andechinoids; upper part relatively thinner bedded, more dolomitic and less fossiliferous than lower part,thickness about 220 feet. Fredericksburg Group - Limestone,dolomite,chert, marl. Limestone nodular, aphanitic, marly, gray, yellow, white, pink; dolomite, fine grained, gray; chert, in thin layers and nodules; marl locally gypsiferous, gray. Abundant Exogyra texana some beds made almost entirely of Gryphaea sp., exposed thickness 50 feet. Edwards Limestone, limestone, dolostone, and chert 60-350 feet thick. Comanche Peak Limestone 80 feet thick. Keys Valley Marl, soft, white as much as 50 feet thick. Cedar Park Limestone similar to Comanche Peak Ls (fine to very fine grained, fairly hard, nodular, light gray, burrowed). Bee Cave Marl soft, white Exogyra texana abundant, thickness 25-40 feet. Wells – Identify all recorded and unrecorded wells on site (test holes, monitoring, water, oil, unplugged, capped and/or abandoned wells, etc.): There are (#) wells present on the project site and the locations are shown and labeled (#’s)The wells are not in use and have been properly abandoned. (#’s)The wells are not in use and will be properly abandoned. (#’s)The wells are in use and comply with 16 TAC Chapter 76. There are (#’s) wells that are off-site and within 150 feet of this site. 0 0 0 0 0 WPD ERM ERI-2014-01 Page 3 of 6 B-0933 of 5311. THE VEGETATION REPORT Provide the information requested below: Brief description of site plant communities (Attach additional sheets if needed): The far northwestern portion of the site in the vicinity of the rimrocks contains native vegetation including live oak (Quercus virginiana), cedar elm (Ulmus crassifolia), and sugarberry (Celtis laevigata). The remaining property is landscaped with St. Augustine grass (Stenotaphrum secundatum) being the predominant ground cover. Umbrella sedge (wetland 1) was observed adjacent to the boat dock. There is woodland community on site If yes, list the dominant species below: . YES NO (Check one). Woodland species Common Name Scientific Name There is grassland/prairie/savanna on site If yes, list the dominant species below: .. YES NO (Check one). Grassland/prairie/savanna species Common Name Scientific Name There is hydrophytic vegetation on site If yes, list the dominant species in table below (next page): .. YES NO (Check one). WPD ERM ERI-2014-01 Page 4 of 6 B-0934 of 53Hydrophytic plant species Common Name Scientific Name Umbrella Sedge Cyperus involucratus Wetland Indicator Status FACW A tree survey of all trees with a diameter of at least eight inches measured four and one- half feet above natural grade level has been completed on the site. (cid:3) (cid:133)YES (cid:133) NO (Check one). x 12. WASTEWATER REPORT – Provide the information requested below. Wastewater for the site will be treated by (Check of that Apply): (cid:13) On-site system(s) (cid:13) City of Austin Centralized sewage collection system (cid:13) Other Centralized collection system x Note: All sites that receive water or wastewater service from the Austin Water Utility must comply with City Code Chapter 15-12 and wells must be registered with the City of Austin The site sewage collection system is designed and will be constructed to in accordance to all State, County and City standard specifications. (cid:3) (cid:133)YES (cid:133) NO (Check one). ■ Calculations of the size of the drainfield or wastewater irrigation area(s) are attached at the end of this report or shown on the site plan. (cid:133)YES (cid:133) NO (cid:133) Not Applicable (Check one). ■ Wastewater lines are proposed within the Critical Water Quality Zone? (cid:3) (cid:133)YES (cid:133) NO (Check one). If yes, then provide justification below: ■ WPD ERM ERI-2014-01 Page 5 of 6 B-0935 of 53B-0936 of 53t e e h s k r o W e r u t a e F l a t n e m n o r i v n E l a c i t i r C - y r o t n e v n I e c r u o s e R l a t n e m n o r i v n E n i t s u A f o y t i C e g r a h c s i D S N O I S N E M D I . t s E s g n i r p S E R U T A E F E G R A H C E R F F U L B / K C O R M R I ) t f ( S N O I S N E M D I s f c d n e r T Z Y X i t h g e H g v A h t g n e L ) t f ( S N O I S N E M D I ) s r e t e M n i 4 8 9 1 S G W ( ) s r e t e M n i 4 8 9 1 S G W ( n o i t t a o n i t e a n d r o o c n o i t t a o n i t e a n d r o o c D I E R U T A E F ) 1 - S g e ( D N A L T E W E D U T I T A L E R U T A E F E D U T I G N O L E R U T A E F E P Y T E R U T A E F e g r a h c e R , s f f u B l i , k c o r m R d n a l t e W , { } g n i r p S , e r u t a e F Y 6 X 4 4 0 0 8 7 . 3 1 7 6 1 6 . 7 2 0 4 1 6 2 7 2 5 3 3 1 d n a l t e W d n a l t e W : r e b m u N e n o h P : y B d e r a p e r P : s s e r d d A l i a m E : e m a N t c a t n o C y r a m i r P 5 6 7 8 1 2 0 2 , 2 2 h c r a M d e s v e r i , 0 2 0 2 , 6 1 r e b m e v o N : e t a D y r o t n e v n I e c r u o s e R l a t n e m n o r i v n E : e m a N t c e o r P j : e t a D t i s i V e t i S : s s e r d d A t c e o r P j 1 2 3 4 9 8 f o 7 e g a P 1 0 - F E C - I R E M R E D P W e t a m i x o r p p a e h t d n a n o i t c e l l o c a t a d e t a n i d r o o c f o d o h t e m e h t e t a t s e s a e P l . t n e m e r u s a e m i f o t i n u e h t d n a s t n o p e h t f o y c a r u c c a d n a n o i s i c e r p w o e b l l a e s y l p p a s t s i l g o o e G l a n o i s s e f o r P r e t e m - b u s y c a r u c c A r e t e m 1 > r e t e m d o h t e M S P G d e y e v r u S r e h t O S E Y O N S M D D D . e t r e t a w d n u o r g f m a e r t s r o l o o p o e c r u o s a s d e e f t e h a h t t a c o l , p e e s r o g n i r p s a r o F . a e r a d e t a m i t s e e h t d n a e r u t a e f e h t f o i d o r t t n e c e a m x o r p p a i e h t e t a c o l , s d n a l t e w r o F e h t f o t i n o p d m e h i t e t a c o l , k c o r m . e r u a e t f e h t s e b i r c s e d t e a r h u t t t a n e e F m e g g e r a s h c e R i r k r o c F o r m R i d n a l t e W g n i r p S p e e S y l n O e s U n i t s u A f o y t i C : R E B M U N E S A C B-0937 of 53List of Attachments for the Environmental Resource Inventory Form Figure 1: Site Specific Geological Map with 2’ Topography Figure 2: Historical Aerial Imagery Figure 3: Site Soils Map Figure 4: Critical Environmental Features and Well Locations Figure 5: CWQZ and Fully Developed Floodplain Figure 6: 3800 Island Way - ERI Site Photos B-0938 of 53Qal Wa Kgru Kfr Legend 2' Contours (CoA) Geologic Atlas of Texas - 250K (TNRIS) Parcel of Interest (CoA) Figure 1: Site Specific Geologic Map with 2' Topography 3800 Island Way Travis County, Texas Map Base: 2020 CAP Area 3in NC Imagery from TNRIS Map Datum: NAD 1983 UTM Zone 14N, meters Map Date: November 12, 2020 0 25 50 100 Feet Geologic Formation Kgru: Glen Rose Formation Kfr: Fredericksburg Group Qal: Alluvium Wa: Water ¯ 1:855 B-0939 of 53Legend Parcel of Interest (CoA) Figure 2: Historical Aerial Imagery 3800 Island Way Travis County, Texas Map Base: 1996 TOP CIR Aerial Imagery from TNRIS Map Datum: NAD 1983 UTM Zone 14N, meters Map Date: November 12, 2020 0 25 50 100 Feet ¯ 1:855 B-0940 of 53TeE TeF Soils HdE: Hardeman soils and Urban land, 3 to 12 percent slopes TeE: Eckrant soils and Urban land, 5 to 18 percent slopes TeF: Eckrant soils and Urban land, 18 to 40 percent slopes W: Water Legend Parcel of Interest (CoA) Soils (USDA/NRCS) Figure 3: Site Soils Map 3800 Island Way Travis County, Texas Map Base: 2020 CAP Area 3in NC Imagery from TNRIS Map Datum: NAD 1983 UTM Zone 14N, meters Map Date: November 12, 2020 0 25 50 100 Feet HdE W ¯ 1:855 B-0941 of 53k 1 c Rimro Wetland 1 k 2 c o Rimr Legend Rimrock (CoA) Parcel of Interest (CoA) Wetland Rimrock 150' Buffers Wetland 150' Buffer Figure 4: Critical Environmental Features and Well Locations 3800 Island Way Travis County, Texas Map Base: 2020 CAP Area 3in NC Imagery from TNRIS Map Datum: NAD 1983 UTM Zone 14N, meters Map Date: March 22, 2021 0 37.5 75 150 Feet No Wells on this Map. ¯ 1:1,200 B-0942 of 53Legend Parcel of Interest (CoA) Lakes Austin Fully Developed Floodplain CWQZ (CoA) Edwards Aquifer Recharge Zones (CoA) Figure 5: CWQZ and Fully Developed Floodplain 3800 Island Way Travis County, Texas Map Base: 2020 CAP Area 3in NC Imagery from TNRIS Map Datum: NAD 1983 UTM Zone 14N, meters Map Date: November 12, 2020 0 25 50 100 Feet ¯ 1:880 B-0943 of 53Figure 6. 3800 Island Way ERI Site Photos Photo 1: Front of the property adjacent to Island Way. Photo was taken from Island Way facing southwest. Photo 2: Back (northwest) of the property adjacent to Rimrock 1 (Figure 4). Photo was taken from Island Way facing west. B-0944 of 53Photo 3: Backyard of property facing Lake Austin to the southeast. Photo 4: Rock retaining wall 2’ above the water line with no wetlands along the shoreline. Photo was taken from the boat dock facing west. B-0945 of 53Photo 5: View of back of residence taken from second floor of boat dock facing northwest. Photo 6: Rimrock 1 (Figure 4) extends southwest and northeast of property. Photo was taken from Island Way facing southwest toward the property. B-0946 of 53Photo 7: Wetland 1 adjacent to the boat dock consisting of landscaped umbrella sedge (Carex involucratus). Photo was taken by City of Austin staff from the boat dock facing northwest toward the residence. B-0947 of 53March 22, 2021 ATTACHMENT 4 BASIS OF DETERMINATION FOR THE FINDINGS OF FACT City of Austin | Environmental Commission Variance Application Guide 8 B-0948 of 53A. 1. The requirement will deprive the applicant of a privilege available to owners of similarly situated property with approximately contemporaneous development subject to similar code requirements. YES. The Environmental Commission has recommended every variance application pertaining to LDC 25-8-281(C)(2)(b) for the past six years except one which included a tram. 2. The variance: a. Is not necessitated by the scale, layout, construction method, or other design decision made by the applicant, unless the design decision provides greater overall environmental protection than is achievable without the variance; YES. The entire shoreline is within the CEF setback. The proposed dock will be constructed in the same location as the existing dock. b. Is the minimum deviation from the code requirement necessary to allow reasonable use of the property; YES. A dock cannot be constructed on the lot without obtaining this variance. c. Does not create a significant probability of harmful environmental consequences. YES. Post construction, all disturbed areas will be revegetated per the COA 609S specification. Floating silt screen will contain sediment caused by any lakebed disturbance. 3. Development with the variance will result in water quality that is at least equal to the water quality achievable without the variance. YES. Mitigation plantings will be added to the site which should result in a greater water quality from overland flow entering the lake. The floating silt screen should contain any sediment caused by the boat dock construction. B. 1. The criteria for granting a variance in Subsection (A) are met: YES. Please see answers to A (1), (2), and (3). 2. The requirement for which a variance is requested prevents a reasonable, economic use of the entirety of the property; YES. The existing dock, built in the 1980s, is oriented parallel to the shoreline on a very busy section of the lake. The wave action makes for a perilous entry and exit to/from the boat. Reconstructing the dock to a safe alignment perpendicular to the shoreline, as is typical today, requires this variance. Blocking the B-0949 of 53construction of a safe dock “prevents a reasonable, economic use of the entirety of the property”. 3. The variance is the minimum deviation from the code requirement necessary to allow a reasonable, economic use of the entire property; YES. The construction is limited to replacing an unsafe dock with a safe dock. No further work is proposed; so this project “is the minimum deviation from the code”. Denying the owner the ability to construct a safe dock on the lakefront lot would prevent “a reasonable economic use of the entirety of the property”. B-0950 of 53Applicant Exhibits B-0951 of 53 ENVIRONMENTAL COMMISSION MOTION 20210616 004a Date: June 16, 2021 Seconded by: Perry Bedford Subject: 3800 Island Way SP-2021-0021D Motion by: Kevin Ramberg RATIONALE: WHEREAS, the Environmental Commission recognizes the applicant is requesting a variance from LDC 25- 8-281(C)(2)(B) to allow construction within 150-feet of Critical Environmental Feature (Rimrock). WHEREAS, the Environmental Commission recognizes that staff recommends this variance (with one condition) having determined the required Findings of Fact have been met. THEREFORE, the Environmental Commission recommends the variance request with the following: Staff Condition: 1. That the construction be completed by barge. VOTE 8-0 For: Bedford, Creel, Thompson, Brimer, Ramberg, Barrett Bixler, Bristol, and Guerrero Against: None Abstain: None Recuse: None Absent: Coyne Approved By: Linda Guerrero, Environmental Commission Chair B-0952 of 53B-0953 of 53