LCRA Highland Lakes Watershed Ordinance Performance Standards Overview

How Does Stormwater Pollution Affect Our Waterways? Siltation of creeks and reservoirs Reduced fish and wildlife habitat Algal blooms and fish kills Increased growth of aquatic weeds Reduced recreational opportunities because of bacterial contamination Contamination of food and water sources Construction-generated sediment changes the character of runoff from natural conditions– existing soils are pulverized by mechanical action of rock saws, hydraulic rams, construction traffic. Top soils and subgrade materials may be imported or moved within the site; Top soils are removed, often leaving poor mineral soils on the surface. The landscape and hydrology is changed by the addition of pollutants including fertilizers, pesticides, oil/grease, metals. Impervious surfaces gather these pollutants between rainfall events and discharge them to waterways during rainfall. Quarry and Mine Activities often have similar characteristics.

HLWO Jurisdictional Area Travis County (Lake Travis Watershed) Llano County (portion) Burnet County (Colorado River Watershed) Total Area 1,172 sq. mi.

What is regulated? Development (single family, subdivisions, multi-family, and commercial) that adds more than 10,000 sq. ft. of impervious cover or disturbs more than 1 acre of land Mine or Quarry projects that create more than 10,000 sq. ft. of impervious cover or disturb more than 5 acres of land Utility line construction and maintenance Dredge and Fill Standards (No permit required) Exemptions No Permit Required

HLWO Performance Standards Performance Standards Minimum Requirements Pre-development Planning Meeting with LCRA staff to review project Water Quality Management Plan showing drainage layout and BMP design information Buffer Zones Plan showing buffer zones for creeks, and buffer zone protection measures Construction- Phase Construction-phase erosion control plan with Erosion and Sediment details and specifications Control Water Quality Education Contact LCRA to initiate education program

Permanent BMPs to Manage Hydrology and Water Quality Design objective – manage Streambank Erosion and Stormwater Pollutant Removal by intercepting and treating a water quality volume Design Storm – 1 year, 3 hour – 1.93” BMP Suites- primary and secondary BMPs Primary BMPs (water quality basins) Secondary BMPs (filter strips & infiltration devices) BMPs placed in series to manage channel erosion and treat runoff quality Pollutant removal performance – remove 70-75% of TSS, TP, oil and grease

Permanent Water Quality Basins Bioretention basins (stand – alone) Extended detention basins* Sand filters* Wet ponds (stand-alone with vegetated bench) Wetland basins Retention – irrigation (stand – alone) Infiltration systems (secondary only) *must be combined with a secondary BMP

Marble Falls – Edwards Offices Stand-alone bioretention basin Vegetated filter strip for driveway

Marble Falls – RSC Equipment – ED pond with secondary bioretention

Questions ?? Contacts LCRA Watershed Engineering & Planning 512-473-3200 Ext. 2324 Supervisor: Erik Harris, P.E. Ext. 2091 Permit Review: Adam Boatright, P.E. Ext. 4080 Dean Thomas, P.E. Ext. 2892 Inspections: Supervisor: David Williams Ext. 3597 Mark Neuman – North Ext. 2518 Brian Box - South Ext. 3303 Melissa Gabriel –Maintenance Ext. 2838 www.lcra.org Go to “Water” then “Quality”, then select “Watershed Management Ordinance”