Proposed amendment addresses impervious cover

By Anthony Armstrong, Engineering Services & Construction Inspections Manager

Driveways, parking, and accessory areas are a necessary part of any residential development. Unfortunately, if they cover too much ground, these water-limiting – or impervious – surfaces can often wreak havoc through flooding and erosion.

Impervious surfaces are any materials or construction that limit the absorption of water by covering the natural land surface. Materials used for landscaping in non-loadbearing areas aren’t considered impervious surfaces.

In College Station, the problem has emerged as the city has grown, especially in the redevelopment of lots in older neighborhoods that lack modern drainage and retention capabilities. Existing city regulations don’t limit impervious surfaces, which means residential lots can be completely or mostly covered.

A proposed amendment to the Unified Development Ordinance would provide a maximum percentage of a lot that may have an impervious cover. The percentages vary and would be implemented and assessed based on the zoning district, or a detailed engineered design.

The Planning and Zoning Commission will consider the amendment at its next meeting on Thursday, Feb. 20, followed by city council action on March 9. Both meetings will include a public hearing.

Newer neighborhoods with detention assume a certain amount of impervious surfacing when designed. The proposed amendment would allow them to abide by those assumptions.

The regulations would apply only to residential zoning districts and would not include multi-family and mixed-use zoning designations. Those zoning districts and commercial/non-residential districts would still require a detailed drainage analysis of individual lots as part of the permitting process.

Here are the proposed redline changes in the UDO:


About the Blogger

Anthony Armstrong PE has been with the city since 2016 and is in his first year as Engineering Services & Construction Inspections Manager. A native of Bulverde, Anthony served as an engineer with CME Testing and Engineering after earning a bachelor’s degree in civil engineering from Texas A&M in 2015.


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