Stormwater management can be accomplished with gravity-fed open channel or closed conduit. In places where gravity drainage is impossible or not economically feasible, pump stations will be required to drain depressed sections of the roadway.

Discharge controls are often needed to mitigate the runoff quantity and/or quality impacts. Outlet controls can reduce the rate of discharge. Retention facilities are used to control the quantity and quality of runoff discharged to receiving waters and must be considered for use as a mitigation measure to reduce the runoff impact to receiving water quality. Refer to the HDM for additional discussion on the design of stormwater management drainage design.

Pump station design includes pump sizing, foundation design, outfall design, power/control design, and enclosure design for facilities to handle storm water in areas that cannot drain by gravity. Pumps may also be needed for wetland restoration or storm water detention facilities. The hydraulic design of pump stations includes selecting the type, capacity, and power of the pumps, determining the on/off cycling requirements, providing for trash collection, and designing a discharge chamber.

A pump station must be protected and secured with fences, gates, grates, and locks. Ample access for working areas and maintenance vehicles must be provided since pumps are mechanical, susceptible to failure, and require extensive maintenance. For this reason, pumps must be used only when absolutely necessary. Also, backup systems must be considered.

Texas Evacuation Routes must be designed to drain by gravity only, if possible, because the likelihood of a pump station failure may be greatest during the time of most critical need.

Considerations in the hydraulic design of pump stations include: