20220216-004a: Violet Crown SERs #5111 & #5112 Staff Memo — original pdf

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ITEM FOR ENVIRONMENTAL COMMISSION AGENDA COMMISSION MEETING DATE: February 16, 2022 NAME & NUMBER OF PROJECT: Violet Crown Water and Wastewater Service Extension Requests #5111 and #5112 NAME OF APPLICANT OR ORGANIZATION: Jim Wittliff, Land Answers, Inc. LOCATION: 10649 SH 71 Austin, Texas 78736 COUNCIL DISTRICT: Austin 2-Mile Extraterritorial Jurisdiction PROJECT FILING DATE: October 21, 2021 WPD/ENVIRONMENTAL STAFF: Kaela Champlin, Environmental Program Coordinator, Watershed Protection Department (512) 974-3443, kaela.champlin@austintexas.gov WATERSHED: REQUEST: STAFF DETERMINATION: Barton Creek Watershed, Barton Springs Zone, Edwards Aquifer Contributing Zone, Drinking Water Protection Zone Water and Wastewater Service Extension Staff does not recommend approval of the water and wastewater service extension requests 1  MEMORANDUM TO: FROM: Linda Guerrero, Chair, and Members of the Environmental Commission Kaela Champlin, Environmental Program Coordinator, Watershed Protection Department February 16, 2022 DATE: SUBJECT: Violet Crown Water and Wastewater Service Extension Requests #5111 and #5112 Service Extension Requests (SER) located in the Drinking Water Protection Zone and outside of the City of Austin’s full purpose jurisdiction require Council approval and review by the Environmental Commission. Watershed Protection Department (WPD) staff have completed the review for Violet Crown Water and Wastewater Service Extension Requests and recommend denial of the requests. Site Overview The site consists of multiple tracts comprising a total of approximately 70.95 acres, located at 10649 SH 71, within the City of Austin’s 2-mile Extraterritorial Jurisdiction. The project proposes a mixed-use development, including multifamily residential, office, an amphitheater, and other uses. See the chart provided below that summarizes the proposed uses within the development and the associated Land Use Equivalents (LUEs) that are proposed. The project is currently in site plan review with the City of Austin (Case number: SP-2021-0262D). Proposed Development Intended Uses (Residential) Multi- Family Proposed Development Intended Uses (Commercial) Office (sq. ft.) Office Warehouse (sq. ft.) Retail (sq. ft.) Restaurant (sq. ft.) Amphitheater (persons) Units 513 Units 40,000 25,808 49,813 23,422 17,000 LUE Conversion (LUE per Unit) 0.5 LUE Conversion (LUE per Unit) 3,000 4,000 1,660 200 50 Total LUEs LUEs 257 LUEs 14 7 30 118 340 766 2 Environmental Impacts The property is in the Barton Creek Watershed, the Barton Springs Zone, the Edwards Aquifer Contributing Zone, and the Drinking Water Protection Zone. The site is also subject to the Save Our Springs Ordinance. The property does not contain any known critical environmental features, critical water quality zone, or water quality transition zone. The site does not drain to known occupied salamander habitat. However, there are significant areas of slopes greater than 15%. Due to these slopes, Land Use Commission variances for cut and fill will be required associated with the proposed site plan currently under review. Although there are no sensitive environmental features onsite, the property is located in the Barton Springs Zone, an environmentally sensitive area. The property is adjacent to the Barton Creek Habitat Preserve, which provides habitat for migratory songbirds, including the endangered Golden-cheeked Warbler, and protects water quality in the Barton Creek watershed. The City of Austin also recently purchased a conservation easement for water quality protection adjacent to this site. Concerns regarding impacts on water quality, building size, lighting/night sky issues, and traffic issues from the development have been expressed to WPD staff from vested stakeholders. Additionally, the proposed water and wastewater infrastructure necessary to bring service to this site is significant and crosses critical water quality zones and water quality transition zones for Barton Creek and Williamson Creek. At this time, the plans for which side of the highway the water and wastewater infrastructure will be located are not known. Impacts to potential critical environmental features that may be associated with these creeks are also not known at this time. Development Impacts Water: The proposed water improvements include construction of approximately 16,495 feet of 16-inch water main from the existing 12-inch water main located at the subject tract in SH 71 W, south- southeast along SH 71 W to Thomas Springs Road, and then west-southwest along Thomas Springs Road to the existing 20-inch water main located at the Thomas Springs Elevated Storage Tank site as shown on the attached map. The connection to the existing 20-inch water main will be made outside the fence at the elevated storage tank site. The layout of the proposed water main would cross at least one (or possibly two) critical water quality zones and water quality transition zones for Barton Creek. While necessary utilities are allowed to cross critical water quality zones (CWQZs) if certain conditions are met as set forth in the LDC, CWQZ crossings of utility lines within the Barton Springs Zone must also be approved by the Director of Watershed Protection Department, per LDC Section 25-8-261(D)(3). At this time there is not sufficient information to determine whether or not the necessary utility crossing for the water main would be supportable by WPD. While drinking water breaks do not typically cause the same level of environmental harm as wastewater breaks, chlorinated water does have negative effects on aquatic life. 3 Wastewater: The proposed wastewater improvements include the construction of an appropriately sized public lift station at the approximate location within the subject tract as shown on the attached map. The applicant shall also construct approximately 15,150 feet of appropriately sized force main from the proposed lift station east through the subject tract to west SH 71 and then south-southeast along west SH 71 to the existing 8-inch gravity wastewater main. The applicant shall also construct approximately 1,950 feet of 12-inch gravity wastewater main from the existing 25-inch wastewater interceptor northwest along SH 71 to MH ID #268789. The proposed 12-inch gravity wastewater main will replace the existing 8-inch wastewater main located along this path and all existing services will be reconnected to the proposed 12-inch gravity wastewater main. If the applicant cannot achieve a minimum slope of 0.80%, a 15-inch gravity wastewater main at a minimum slope of .25% may be installed in lieu of an 8-inch gravity wastewater main at 0.80%. Construction of the wastewater main and lift station are required by LDC Chapter 25-8 to be located outside of the water quality transition zone and critical water quality zone, except for necessary utility crossings. The layout of the proposed wastewater main crosses at least one (or possibly two) critical water quality zones and water quality transition zones for Barton Creek and Williamson Creek. While necessary utilities are allowed to cross critical water quality zones (CWQZs) if certain conditions are met as set forth in the LDC, CWQZ crossings of utility lines within the Barton Springs Zone must be approved by the Director of Watershed Protection Department, per LDC Section 25-8-261(D)(3). At this time there is not sufficient information to determine whether or not the necessary utility crossings would be supportable by WPD. Alternative Wastewater Service: The site is allowed 20% net site area impervious cover. If service is not extended to the site and wastewater disposal is required, the applicant would likely apply for a Texas Land Application Permit (TLAP) issued by the Texas Commission on Environmental Quality. This would require an estimated amount of roughly 30 acres for wastewater irrigation, which would need to be deducted from the net site area calculations associated with impervious cover limits. This area also contains steep slopes, which may further limit the amount of suitable area for wastewater irrigation. Based on this assessment, the proposed project will not be able to develop with the same level of intensity if the wastewater SER is not granted. Recommendation WPD staff recommend denial of Violet Crown Water and Wastewater Service Extension Requests #5111 and #5112 for the following reasons: • The impacts from the proposed water and wastewater line would require significant infrastructure improvements in an environmentally sensitive area that the City of Austin is actively working to protect for water quality and endangered species protection. The attached information provides further detail on the applicant’s request. Please feel free to contact Kaela Champlin at (512) 974-3443 or kaela.champlin@austintexas.gov if you have any questions or comments about the proposed SER. cc: Cole Huggins, P.E., Austin Water Colleen Kirk, P.E., Austin Water 4  Liz Johnston, Deputy Environmental Officer, Watershed Protection Department Katie Coyne, Environmental Officer, Watershed Protection Department 5