Tag Archive for: Willow Creek

Willow Creek Widening and Stormwater Detention Basins Improving Tomball Drainage

Harris County Flood Control District (HCFCD) has a large active construction project underway in Tomball. Phase I of the project stretches about two-thirds of a mile from SH249 to FM2920 on a tributary of Willow Creek as it arcs around a major shopping center near downtown Tomball and Lone Star College/Tomball. The project includes channel widening and deepening; dry and wet stormwater detention basins; and opportunities for recreational trails.

Limits of Phase 1 are within red oval. Additional improvements (M124-00-00-E002) will extend further south to Willow Creek itself as additional money becomes available.

Willow Creek: A Study in Contrasts

The Willow Creek watershed is located in northwest Harris County. It drains about half of the City of Tomball. The tributary highlighted above flows through densely developed shopping and medical center areas on the northern end to agricultural and oil and gas interests on the lower end.

Looking SW at southern limit of construction toward agricultural and rural areas beyond. FM2920 leads into distance.
Looking NE in opposite direction toward area of channel widening and detention basins. SH249 cuts left to right across top of frame. FM2920 cuts through upper right corner. Tomball in upper right.
HCFCD contractors were hard at work on Christmas Eve afternoon when I took these shots.
Closer shot of detention ponds north of shopping center out of frame on the right.

Willow Creek: Present and Future

Willow Creek flows into Spring Creek just upstream of where Spring Creek crosses under I-45. The Willow Creek watershed covers about 54 square miles. The downstream end of the watershed is within the floodplain of Spring Creek.

Willow Creek Watershed and current HCFCD projects in various stages of completion. This post is about the one near the top center of the frame ending in E001.

Willow Creek watershed is mostly undeveloped. Significant development is limited to the City of Tomball and a few residential subdivisions in the lower end. The development rate has not been very rapid. However, officials expect it to increase as the City of Tomball continues to expand and urbanization from Houston stretches northwest.

This project will directly benefit mostly areas on the northwest side of the county. However, it may provide some downstream benefit by holding back water in major floods.

Goal: Contain Runoff from 100-Year Event

Phase 1 of this project began construction activities in January 2021. As funding becomes available, future phases of the M124-00-00 project will continue channel conveyance improvements and construct several more stormwater detention basins from F.M. 2920 to the confluence with Willow Creek. Phase II will also deepen the channel improvements from Phase 1 that you see above.

The overall goal of the M124-00-00 project is to enable the channel to contain the 1-percent (100-year) storm event within the channel banks based on existing watershed conditions.


The total project focuses on conveyance improvements of stormwater in the area, as well as reducing flood risk through construction of stormwater detention basins. Stormwater detention basins reduce flooding risks by taking in and temporarily storing stormwater during heavy rain events and releasing the water back into the waterways when the threat of flooding has passed.

Multiple new detention basins along the M124-00-00 channel will add approximately 390 million gallons of storage capacity (an approximate 2,164 percent increase in current storage capacity) to benefit the Willow Creek watershed. That’s enough to contain a foot of water falling on 1200 acres.

Posted by Bob Rehak on 12/26/2021 based on info from HCFCD.org

1579 Days since Hurricane Harvey