20241204-003: Loyola Flats Presentation — original pdf

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LOYOLA FLATS Miranda Reinhard Environmental Scientist Senior, Watershed Protection Department 6700 DECKER LANE, 78724 SP-2024-0147C.SH 1 PROJECT LOCATION [2 PROPERTY DATA • Elm Creek Watershed • Suburban Classification • Desired Development Zone • Full Purpose Jurisdiction • Council District 1 [3 Lake Walter E. Long Colony Park PROPERTY DATA Project Location Lake Walter E. Long Colony Park Travis County Exposition Center Travis County Exposition Center [4 PROPERTY DATA • Environmental features: • Critical Water Quality Zone • Wetland CEF • 2 Wetland Critical Environmental Features (CEFs) on-site • Partially excavated detention pond from previous site plan [5 VARIANCE REQUEST LDC 25-8-261(G) – CRITICAL WATER QUALITY ZONE DEVELOPMENT Floodplain modifications prohibited in the CWQZ unless one of the exemptions is met. 1. The variance request is to allow floodplain modification for development within the CWQZ. 6 Proposed 100- Year Floodplain Existing 100-year Floodplain VARIANCE REQUEST 25-8-261(G) • Floodplain modifications are prohibited in the CWQZ unless one of the exemptions is met. 7 [ VARIANCE REQUEST Functional Assessment of Floodplain Health (ECM Appendix X): • Floodplain is in “Fair” condition • Excellent  Good  Fair  Poor 8 VARIANCE REQUEST Floodplain Restoration/Mitigation Ratios ECM 1.7.5 & ECM 1.7.6 • • Zone 1 (Floodplain outside the Total Modification Area: 1.96 acres • 2.52 acres (Required Restoration/Mitigation) • Zone 2 (Floodplain within the CWQZ) • 0.84 acres • FAIR 3:1 CWQZ) • 1.12 acres • FAIR 6:1 • 6.72 acres (Required Restoration/Mitigation) • Total Required Restoration and/or Mitigation Area: 9.24 acres Zone 1 Floodplain Modification Area Zone 2 Floodplain Modification Area 9 [ VARIANCE REQUEST Floodplain Restoration/Mitigation Ratios ECM 1.7.5 & ECM 1.7.6 • • • • Total Required Restoration and/or Mitigation Area:) 9.24 Acres Zone 1 (Floodplain outside the CWQZ • 2.52 acres • 0 acres (Restored) • 2.52 acres (Mitigated) • Zone 2 (Floodplain within the CWQZ) • 6.72 acres • 0.61 acres (Restored) • 6.11 acres (Mitigated) Total Restoration Area: 0.61 Acres Total Mitigation Area: 8.63 Acres • $382,157.63 Riparian Zone Mitigation Fund payment 10 VARIANCE REQUEST Total Restoration Area (Wetland CEF Mitigation & Floodplain Restoration) • Maximizing restoration area in CWQZ 11 VARIANCE REQUEST Enhancements • ~44,000 sq ft of additional wetland mitigation • Native plantings in biofiltration pond • Native seeding in detention pond • Enhanced outfall • Native trees, shrubs, and bunchgrasses in CEF setbacks & mitigation areas • Native pollinator species • Wetland CEF mitigation plantings • Floodplain restoration plantings 12 VARIANCE REQUEST Enhancements: • Edge barrier of limestone blocks around perimeter of modified CEF setbacks/ restoration areas • Wetland CEF educational signage Edge barrier Educational signage 13 VARIANCE RECOMMENDATION • • Staff determines that the findings of fact have been met: Similar variances have been granted for projects with similar code requirements. The variance • • • Is necessitated by topographic features, not design choice; Is the minimum deviation from the code; and Is unlikely to result in harmful environmental consequences. • Water quality will be equal to or better than water quality without the variance. 14 VARIANCE CONDITIONS Staff recommends this variance, with the following conditions: 1. Provide ~44,000 square feet of additional wetland mitigation including: 1) native plantings in sedimentation and filtration basins of the biofiltration pond, 2) low-grow native seeding in the detention pond, 3) an enhanced nonerosive pond outfall, 4) planting of native trees, shrubs and bunchgrasses in CEF setbacks and mitigation areas. The Director of WPD may reduce this requirement administratively to allow for a future trail connection to Colony Loop Drive. 2. Provide native pollinator species for wetland CEF mitigation and floodplain restoration plantings. 3. Provide an edge barrier of limestone blocks around the perimeter of the modified CEF setbacks/restoration areas to prevent mowing and/or encroachment in these areas. 15 VARIANCE CONDITIONS Staff recommends this variance, with the following conditions: 4. Provide wetland CEF educational signage next to the CEF setbacks/restoration areas. 5. Provide floodplain restoration plantings of native trees and shrubs for the remaining open area (26,349 square feet/0.61 acres) maximizing restoration within the CWQZ and enhancing the floodplain from an existing condition of Fair to Excellent. 6. Pay $382,157.63 into the Riparian Zone Mitigation Fund for the remaining required floodplain mitigation (376,326 square feet/8.63 acres) using the appropriate ratios per ECM 1.7.6. 16 THANK YOU Questions? 1717