20200520-006b: Persimmons Construction Plans, C8-2019-0080.1B.SH presentation — original pdf

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PERSIMMONS CONSTRUCTION PLAN 7051 MEADOW LAKE BOULEVARD AUSTIN, TEXAS 78744 C8-2019-0080.1B.SH Jonathan Garner Environmental Review Program Coordinator Development Services Department PROPERTY DATA • 1.98 acres (gross site area) • Full-purpose Jurisdiction • Council District 2 • Desired Development Zone • Onion Creek Watershed (Suburban classification) • Not located over Edwards Aquifer Recharge Zone • Current code regulations apply 2 Persimmons Construction Plans C8-2018-0080.1B.SH Site Location Austin ETJ Austin City Limits Edwards Aquifer Recharge Zone Edwards Aquifer Contributing Zone 3 VICINITY EXHIBIT 4 5 VARIANCE REQUEST 2. To allow cut over four feet within 100 feet of a classified waterway (LDC 25-8-341) 6 PROPOSED CONSTRUCTION PLAN 7 PROPOSED CONSTRUCTION PLAN 8 CUT EXHIBIT 9 FINDINGS OF FACT (LDC 25-8-41) 0 1 FINDINGS OF FACT (LDC 25-8-41) • 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. • Staff determination: No. Roadway construction crossing a classified waterway occurs all throughout the City of Austin utilizing methods that do not require a variance to City Code requirements. A Code compliant construction method would eliminate the need for the variance request and would not deprive the applicant of a privilege to construct a roadway crossing a classified waterway. 1 1 FINDINGS OF FACT (LDC 25-8-41) • 2a: The variance 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: • Staff determination: No. A construction method that modifies the channel margins, alters the natural flow velocity, and removes hydric soils and vegetation does not provide greater overall environmental protection than a construction method that is achievable without the variance. 2 1 FINDINGS OF FACT (LDC 25-8-41) • 2b: The variance is the minimum deviation from the code requirement necessary to allow a reasonable use of the property: • Staff determination: No. The amount of cut in excess of four feet required for the construction of the crossing occurs within the minimum setback of the waterway buffer and the erosion hazard zone adjacent to the classified waterway. Grading at a depth beyond that allowed by Code within these sensitive environmental areas does not constitute the minimum deviation from the code requirement. 3 1 FINDINGS OF FACT (LDC 25-8-41) • 2c: The variance does not create a significant probability of harmful environmental consequences. • Staff determination: No. The grading associated with the placement of the concrete box culverts, headwalls, and wingwalls will remove soils and existing vegetation and destabilize the stream bank, alter the flow velocity in the channel resulting in downstream incising and bank erosion, and modify sediment deposition patterns beyond natural processes. 4 1 FINDINGS OF FACT (LDC 25-8-41) • 3: Development with the variance will result in water quality that is at least equal to the water quality achievable without the variance. • Staff determination: No. Bank erosion and sediment deposition are two leading causes of degraded water quality in creeks. Siltation can lead to murky water that smothers aquatic life habitat, reduces visibility for aquatic organisms to find food, prevents sunlight from reaching aquatic plants, and conveys other nutrients, pesticides, or toxic compounds that lower the water quality. 5 1 VARIANCE RECOMMENDATION • Staff has determined the required Findings of Fact have not been met, and does not recommend approval of the variance request. 6 1 END OF PRESENTATION 7 1