Sites located over the Edwards Aquifer Recharge Zone or Edwards Aquifer Contributing Zone must comply with restrictions set forth by the Texas Commission on Environmental Quality (TCEQ).
The Edwards Aquifer Contributing Zone is land upstream of the recharge zone that produces stormwater runoff that is conveyed into the Edwards Aquifer Recharge Zone. The Recharge Zone is the land over the Edwards Aquifer that recharges the aquifer.
With a few exceptions in the City of Austin, development is prohibited within Water Quality Transition Zones and Critical Water Quality Zones that are located over the South Edwards Aquifer Recharge Zone (the portion of the recharge zone south of Lake Austin). Of course this statement is meaningless in San Antonio.
Developments located over the Recharge Zone must provide full water quality and detention facilities. Fee-in-lieu of Water Quality and partial sedimentation filtration ponds cannot be utilized as water quality controls.
In addition to receiving a Site Plan Development Permit or building permit from the City of Austin, sites located in the Edwards Aquifer Recharge Zone or Contributing Zone must receive permits from the TCEQ Edwards Aquifer Department. Depending on the site location, either a Water Pollution Abatement Plan (WPAP) or Contributing Zone Plan (CZP) application must be submitted to and approved by the TCEQ. Both applications are accompanied by a report detailing the Water Quality Best Management Practices (BMPs) that the proposed project will utilize. The Water Quality BMPs can either be constructed as part of the proposed project or, if capacity is available, may be existing from a previously constructed development.
For further reading on this subject, check out these articles on the BIG RED Blog: