20210120-003d: Blue Bluff at Wildhorse Ranch C8-2020-0033 variance packet — original pdf

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ITEM FOR ENVIRONMENTAL COMMISSION AGENDA COMMISSION MEETING DATE: January 20, 2021 NAME & NUMBER OF PROJECT: Blue Bluff at Wildhorse Ranch C8-2020-0033 NAME OF APPLICANT OR ORGANIZATION: Kevin Burks, P.E., Kimley-Horn LOCATION: 10621 Blue Bluff Rd, Austin, TX, 78653 COUNCIL DISTRICT: District 1 ENVIRONMENTAL REVIEW STAFF: Pamela Abee-Taulli Environmental Review Specialist Senior, DSD 512.974.1879 pamela.abee-taulli@austintexas.gov WATERSHED: REQUEST: STAFF RECOMMENDATION: STAFF CONDITION: Gilleland Creek Watershed, Suburban Classification, Desired Development Zone Variance request is as follows: Request to vary from LDC 25-8-341 to allow cut over 4 feet to 15 feet and 25-8-342 to allow fill over 4 feet to 15 feet. Staff recommends this variance, having determined the findings of fact to have been met. The Applicant will protect three natural, unclassified drainages. These small waterways with less than 64 acres of drainage will be preserved in a natural state with foot-path trails for pedestrian access to the Critical Water Quality Zone buffers for an unnamed tributary of Gilleland Creek and for Gilleland Creek. Development within these drainage areas will be limited to park amenities such as trails and trail appurtenances (buildings and parking will not be allowed).  Development Services Department Staff Recommendations Concerning Required Findings Blue Bluff at Wildhorse Ranch Project Name: Ordinance Standard: Watershed Protection Ordinance and Ordinance 20020214-028 Vary from LDC 25-8-341 to allow cut over 4 feet to 15 feet and Variance Request: 25-8-342 to allow fill over 4 feet to 15 feet. 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 development circumstances for sites with multiple constraints. Constraints of this site include pronounced changes in elevation, an adjacent existing roadway to which the development must connect, and the fact that approximately one third of the property consists of creek buffers, floodplain, & greenways. Grading variances have been deemed appropriate under similar 2. The variance: a) Yes 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; The site elevation drops off to the east of existing Blue Bluff Rd., making it a challenge to meet Transportation Criteria Manual vertical roadway design criteria and to provide for accessible routes and crossings in compliance with the Americans with Disabilities Act. Multiple rain gardens are proposed so that the site does not have to be severely leveled to achieve drainage to the main, biofiltration pond. Is the minimum deviation from the code requirement necessary to allow a reasonable use of the property; b) Yes The roadway network within the proposed single-family subdivision has been designed to minimize the number of cross streets in order to reduce the amount of cut and fill and to maintain compliance with the Transportation Criteria Manual block-length requirement. At staff request, the applicant has decreased the length of some lots, decreasing the area that needs to be leveled, and terraced some lots, reducing the steepness of fill. They have also increased the number of retaining walls to minimize the footprint of grading. Does not create a significant probability of harmful environmental consequences. c) NA 3. 1. 2. 3. Yes With appropriate erosion and sedimentation controls provided in accordance with Code and Criteria, the proposed cut and fill can be managed during construction, despite the slopes and proximity to waterways. Neither will the completed project create a probability of harmful environmental consequences. Development with the variance will result in water quality that is at least equal to the water quality achievable without the variance. Yes Water quality for the completed project will be code compliant and equal to the water quality achievable without the variance. 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; The requirement for which a variance is requested prevents a reasonable, economic use of the entire property; NA The variance is the minimum deviation from the code requirement necessary to allow a reasonable, economic use of the entire property. NA Staff Determination: Staff determines that the findings of fact have been met. The Applicant will protect three natural, unclassified drainages. These small waterways with less than 64 acres of drainage will be preserved in a natural state with foot-path trails for pedestrian access to the Critical Water Quality Zone buffers (greenways) for an unnamed tributary of Gilleland Creek and for Gilleland Creek. Development within these drainage areas will be limited to park amenities such as trails and trail appurtenances (buildings and parking will not be allowed). Environmental Reviewer (DSD) _____________________________ Pamela Abee-Taulli Date 1/8/2021 Environmental Review Manager (DSD) _____________________________ Mike McDougal Date 1/8/2021 Environmental Officer (WPD) _____________________________ Chris Herrington Date 1/8/2021 September 28, 2020 ENVIRONMENTAL COMMISSION VARIANCE APPLICATION FORM PROJECT DESCRIPTION Applicant Contact Information Variance Case Information Name of Applicant Street Address City State ZIP Code Work Phone E-Mail Address Case Name Case Number Address or Location Environmental Reviewer Name Environmental Resource Management Reviewer Name Applicable Ordinance Watershed Name Kevin Burks, P.E. 10814 Jollyville Rd Building 4, Suite 200 Austin, TX 78759 512-418-4528 Kevin.Burks@kimley-horn.com Blue Bluff at Wildhorse Ranch C8-2020-0033PA Pamela Abee-Taulli John Clement 25-8-341 & 25-8-342 Gilleland Creek Along the east side of Blue Bluff Road, between W Parsons street and E Parmer Lane in Austin, TX. City of Austin | Environmental Commission Variance Application Guide 1 September 28, 2020 Edwards Aquifer Contributing Zone Distance to Nearest Classified Waterway Request 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) Watershed Classification ☐Urban X Suburban ☐Water Supply Suburban ☐Water Supply Rural ☐ Barton Springs Zone Edwards Aquifer Recharge Zone ☐ Barton Springs Segment ☐ Northern Edwards Segment X Not in Edwards Aquifer Zones ☐ Yes X No Gilleland Creek runs just east of Preliminary Plat boundary Water and Waste Water service to be provided by Austin Water Utility The variance request is as follows: 25-8-341 Cut Requirements & 25-8-342 Fill Requirements Existing ____0____ ___0_____ ____0____ Proposed 1,393,141 31.98 38.88% 92.3% of the property falls within the 0% to 15% slope category. The remainder property has slopes exceeding 15% slope. The property ranges in elevation from 482 to 555. There is an assortment of Cedar Elm and Mesquite trees within the site; only two of which exceed 24 caliper inches. On-site soils are Type D Expansive Clays and is identified as Ferris-Heiden complex and Heiden clay by the USGS web soil survey. One wetland CEF and Critical Water Quality Zones exist within the site. Fully developed 25-year and 100-year floodplains exist within the site. City of Austin | Environmental Commission Variance Application Guide 2 September 28, 2020 Clearly indicate in what way the proposed project does not comply with current Code (include maps and exhibits) FINDINGS OF FACT Per the attached cut/fill exhibit, there are areas that require cut/fills greater than 4’. As required in LDC Section 25-8-341, 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. Project: Blue Bluff at Wildhorse Ranch Ordinance: 25-8-341 Cut Requirements & 25-8-342 Fill Requirements Land Use Commission variance determinations from Chapter 25-8-341 and 25-8-342 of the City A. 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 The otherwise developable land located within the 0% to 15% slope category is primarily comprised of slopes closer to 15%. In order to comply with the Americans with Disabilities Act (ADA) requiring 2% cross slope at intersection crosswalks on the local and collector roadways and to meet Transportation Criteria Manual (TCM) requirements for stopping sight distance (for vertical curves and roadway design) and block length maximums, the proposed grades will need to exceed the cut and fill allowed by Chapter 25. This applies to the single-family lots fronting the roadways meeting the ADA and TCM requirements due to access requirements for the lots. The maximum Cut is 14.7 feet. The maximum Fill is 14.9 feet. In addition, the development of adjacent properties will be challenged by the existing topography. It’s highly likely future developments will be pursuing a cut and fill variance request of this magnitude. We also requested and received City of Austin | Environmental Commission Variance Application Guide 3 September 28, 2020 2. The variance: a) similar variances on our Turner’s Crossing project (C8-2018-0091) due to the same TCM design criteria and ADA requirements that were required as part of that subdivision. 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 b) Yes c) Yes Blue Bluff at Wildhorse Ranch is primarily a single-family residential development with roadways and lot layouts generally designed to follow the existing topography to preserve the natural character of the property. In addition, multiple water quality and detention basins have been placed in natural low areas to preserve the existing drainage patterns. We are not changing drainage patterns to route runoff to one basin, and this variance request is not driven by a design decision on our side. Is the minimum deviation from the code requirement necessary to allow a reasonable use of the property; Blue Bluff at Wildhorse Ranch has been designed to minimally deviate from the code to allow for accessible routes and crossings in compliance with the Americans with Disabilities Act, and meet TCM vertical roadway design criteria. The percentage of the property exceeding 8 feet for this property is 6.5%. Specifically, the design accounts for existing constraints such as the elevation of the adjacent connecting roads at City of Austin approved locations and the minimum allowable roadways slopes to allow for ADA compliance. The roadway network has been designed to minimize the number of cross streets to reduce the amount of cut and fill and to maintain compliance with the Transportation Criteria Manual (TCM) block-length requirement. As such, these cross-streets are required to comply with block length requirements outlined in the code. Does not create a significant probability of harmful environmental consequences. The proposed roadways and associated drainage system have been designed to protect the natural character and function of the Critical Environmental City of Austin | Environmental Commission Variance Application Guide 4 September 28, 2020 Features and Critical Water Quality Zones by ensuring they receive the required surface water runoff quantity and quality needed to promote wetland and floodplain health. In addition, the proposed design preserves the natural drainage patterns by detaining and treating stormwater in multiple basins throughout the property. Development with the variance will result in water quality that is at least equal to the water quality achievable without the variance. Yes The proposed design adheres to all water quality requirements outlined within the Environmental Criteria Manual and as such, will result in water quality that is at least equal to water quality achievable without the variance. In addition, the proposed design preserves the natural drainage patterns by detaining and treating stormwater in multiple basins throughout the property. Based on preliminary discussions with Staff, we are comfortable upgrading from the standard full sedimentation/filtration ponds to green water quality controls as an effort to obtain environmental superiority with this variance request. 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): The criteria for granting a variance in Subsection (A) are met; N/A to this variance request. The requirement for which a variance is requested prevents a reasonable, economic use of the entire property; N/A to this variance request. The variance is the minimum deviation from the code requirement necessary to allow a reasonable, economic use of the entire property. N/A to this variance request. 3. 1. 2. 3. **Variance approval requires all above affirmative findings. City of Austin | Environmental Commission Variance Application Guide 5