Stormwater FAQ

What requirements does the City of San Angelo have for the design of stormwater conveyance systems?

The City of San Angelo adopted Article 12.400 of the Code of Ordinances (Stormwater Ordinance) and accompanying Stormwater Design Manual to guide development in the design and construction of stormwater facilities. The ordinance and manual help to ensure that new development or redevelopment accounts for the protection and welfare of the general public in regard to stormwater runoff during the preliminary or design phase of the development.

What construction sites require stormwater permits or controls?

The Texas Commission on Environmental Quality (TCEQ) requires that any construction project that disturbs one acre of land or more develop a Storm Water Pollution Prevention Plan (SWPPP). Projects that disturb five acres of land or more must submit a notice of intent to discharge construction site stormwater runoff, notify the local MS4 operator, and post-construction site notice at the project location in addition to the SWPPP. All construction site projects that disturb any land (even less than one acre) are required to construct erosion control measures to mitigate stormwater pollution from the site.

What is a Storm Water Pollution Prevention Plan (SWPPP)?

An SWPPP is a document that details best management practices (BMPs) for a construction site. It documents the activities and timelines of construction of the project that may have an impact on stormwater runoff quality. A SWPPP also describes and locates physical stormwater controls, such as filter fabric fences, inlet protection, erosion control logs, rock berms, etc., that are to be constructed on or near the site to protect stormwater quality. BMPs noted in the SWPPP must be installed before land is disturbed and maintained throughout the project. Help to develop a SWPPP can be found here.

What is an MS4, and who is the operator?

MS4 stands for Municipal Separate Storm Sewer System. MS4s are stormwater systems that are governed and maintained by public or private entities. The City of San Angelo has an MS4 and the operator is the Stormwater Program Manager. One of the requirements of the permit is for the city to develop a Stormwater Management Plan to manage stormwater and set goals for water quality.  When notices of intent are required by a construction project, the operator of the MS4 into which construction site runoff flows shall be notified. Other MS4s in the San Angelo area include Tom Green County, Goodfellow Air Force Base and Angelo State University. MS4s are regulated by and must be permitted through the TCEQ to discharge stormwater runoff.