Taylor County, TX Environmental Rules: Stormwater Management (2026)

Article VIII, DRAINAGE, requires every subdivision proposal to provide adequate drainage to reduce flood exposure and to size lots so they still leave room to build. 01 requires a registered professional engineer to study both interior and exterior storm water runoff and to document conveyances, easements, base flood elevation data, and finished floor elevations, plus culverts, bridges, and other site-specific features. 04 sets the core performance standard: the peak discharge of storm water runoff, both within the subdivision and the outflow from the subdivision, must not exceed the peak discharge of the property in the undeveloped state, meaning new development cannot dump more water onto neighboring land than the raw land did before.

05 sets the design storms: right-of-way ditches are built to a 10-year rainfall frequency, while structures, culverts, bridges, and low-water crossings are designed to a 25-year flood frequency; where a subdivision road crosses a major creek such as Elm Creek or Jim Ned, the Commissioners' Court sets the design frequency itself. 07 requires an engineer's letter, with as-built drawings, recommending acceptance before the Commissioners' Court will take over the streets and drainage work. 02 lets a subdivision with limited drainage problems narrow the study's scope, but the engineer's report must still show the full range of requirements was considered.