5 county-level rules, plus city-specific rules for 2 cities in Williamson County, Texas.
Verified from official government sources
Construction over the Edwards Aquifer recharge zone in western Williamson County requires a TCEQ-approved water pollution abatement plan under 30 TAC Chapter 213. Any site disturbing one acre or more also needs coverage under the TPDES Construction General Permit TXR150000.
30 TAC §213.5
Required plans. A plan must be submitted for the following, as appropriate: (1) a water pollution abatement plan under subsection (b) of this section to conduct regulated activities on the recharge zone not covered by subsections (c), (d), or (e) of this section.
On the Edwards Aquifer recharge zone, clearing and excavation are regulated activities under 30 TAC Chapter 213 and require approved erosion and sediment controls. Construction General Permit sites of one acre or more need a stormwater pollution prevention plan with erosion best management practices.
30 TAC §213.3
construction of buildings, utility stations, utility lines, roads, highways, or railroads; clearing, excavation, or any other activities that alter or disturb the topographic, geologic, or existing recharge characteristics of a site.
Williamson County sits in Central Texas, roughly 200 miles inland from the Gulf of Mexico. No beachfront, dune, tidal, or coastal-development rules apply anywhere in the county. This category does not apply here.
Williamson County participates in the National Flood Insurance Program and enforces floodplain development permits in unincorporated areas. Any construction, fill, or improvement in a FEMA-mapped special flood hazard area requires a county floodplain development permit before work begins.
Tex. Water Code §16.315
All political subdivisions are hereby authorized to take all necessary and reasonable actions that are not less stringent than the requirements and criteria of the National Flood Insurance Program, including but not limited to:
Texas counties cannot zone, so unincorporated Williamson County has no general grading ordinance. Placing fill or altering drainage inside a mapped floodplain still requires a county floodplain development permit under state floodplain law.
Tex. Water Code §16.315
All political subdivisions are hereby authorized to take all necessary and reasonable actions that are not less stringent than the requirements and criteria of the National Flood Insurance Program, including but not limited to:
2 cities in Williamson County have their own environmental rules rules. Each link goes to that city's dedicated page with code citations.
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