Stormwater Regulatory Update – Harris County / City of Houston
Over the course of the last few months, much has been written about flooding in Houston. There are two great blog posts that every Houstonian should read to get a basic understanding of the hydrologists perspective on flooding in Houston. The first was written by Michael Bloom and Steve Stagner, “Boomtown, Flood Town Reconsidered: An Engineer’s View” and the second was more of a response by Scott Saenger, “Drainage Solutions are Not One-Size-Fits-All”. As would be expected, we are finally beginning to see a response from Harris County, Harris County Flood Control and the City of Houston as it relates to stricter enforcement on the regulations already in place as well new regulations that are to come.
Changes that are here:
Last March, new regulations were put on retention requirements in the Addicks, Barker and Upper Cypress Watersheds. You can find those new regulations HERE. Among other things, one requirement is providing infrastructure that allows the restrictor on detention ponds to be closed in the event there is a threat of a large storm event, to hold as much water as possible from entering the watershed until the downstream infrastructure has cleared. The result is relief to a system we have seen pushed to its limits over the last few years.
Another change you may begin to see isn’t necessarily new regulation, its just enforcement of an existing regulation. In the last few weeks, several developers and engineers have come to us asking about “new” regulations when it comes to using residential neighborhood ponds that are operated by the MUD for their detention. The impression has been if there is a large MUD operated detention facility that has the capacity to support the surrounding real estate, that detention is not needed. The reality is that if you outfall into a County roadway (as opposed to a HCFCD ditch/ basin), you need to meet County criteria. They will not allow you to flood your immediate neighbors trying to get flows to the regional detention basin; a conveyance path must be included in the design, which becomes a challenge when the infrastructure put in place in the MUD doesn’t typically carry the 100-yr. This is becoming a significant challenge for smaller commercial lots within a MUD that are trying to tie into a MUD pond within proximity of the property.
Changes that are coming:
I put this in the changes that are coming category because although they have been passed, they are not yet being enforced. The City of Houston has changed it’s requirements for a stormwater quality permit from 5 acres or part of a larger common plan of development to 1 acre or part of a larger common plan of development. This change is going to significantly increase the number of stormwater quality permits and should have a dramatic impact on the amount of trash, sediment and other common pollutants that come off of impervious surfaces throughout the City of Houston. You can find the SWQ ordinance HERE. It’s coming, and on average will increase your development costs by about approximately $5,000 per acre.
The last big item related to detention & drainage is that Harris County is working with ACEC to develop criteria to force construction projects to not flood their neighbors. Designers go to great efforts to make sure that after the development is complete, there is no adverse impact to their neighbors or the downstream infrastructure, but what is being required during the construction phase activity? Together, they are working to create a local regulation or policy to force contractors to adhere to a current state law that has at times been ignored, Texas Water Code §11.086: Overflow Caused by Diversion of Water.
There will be more to come on all of these topics later this spring as there will soon be an educational forum announced that will further clarify the City of Houston, Harris County and Harris County Flood Control’s stance on these topics and more. Stay posted.