Drainage

AEL provided the drainage design and hydraulic impact analysis report for the development of a 112 acre plot in Sealy, Texas which is to be turned into a 85 home development.

Each home is to be on a 1-acre plot with ditches running in front of the properties. The Development’s Master plan did not call for a detention pond to mitigate the increased development and imperviousness. Instead the developer tasked AEL to develop the drain-age ditches as an In-line detention facility. Ditches were over-sized and restrictor plates placed in each driveway culvert to restrict the flows and outfall at pre-development rates to the 3 distinct outfalls.

The flows were restricted starting at the upstream-most culvert to hold back as much flow as possible without over-topping and flooding the adjacent properties, this was then repeated going downstream towards the outfall. The systems were modeled in SWMM with Hydrographs developed in HEC-HMS using a combination of City of Sealy, Austin County, and HCFCD criteria.

Once the outfall rate was satisfied, and the ditch network held without over-topping, the system volume detained was calculated to ensure we are meeting the required detention volume and to not require a detention basin as the developer desired. AEL was able to achieve both tasks in a short amount of time with the Client’s and City of Sealy Engineer’s satisfaction and praise to our work.

Client: BEC Engineers and Consultants

Location: 

Austin County, Texas 77474