F-22 Restore Channel Conveyance Capacity on Pillot Gully

Project Description

Project K140-00-00-X023 was a major maintenance project that repaired a structure failure and integrated environmental enhancements by way of natural stable channel design techniques to restore the channel conveyance capacity of K140-00-00 between Vintage Preserve Parkway and Cypress Creek.

K140-00-00-X023 was not a flood damage reduction project; however, the channel was widened in some locations and looks significantly different due to the environmental enhancements. The plans called for natural stable channel design features such as:

• Constructed boulder riffles
• Natural sill logs (to help stabilize the banks)
• Toewood (to help prevent erosion)
• Live stakes and planting of native vegetation

On-site sourced wood was used for channel stability and the Flood Control District worked to minimize impacts to the trees and vegetation in the area. Portions of the channel were considered to be in serious failure and these repairs were necessary to prevent further impact to the channel and surrounding trail system. Phase I was completed in December 2020. During this phase, slopes and banks along a 2,830-foot-long area downstream from Vintage Preserve Parkway were repaired and then seeded with turf species to help stabilize the newly restored slopes and prevent future erosion. Phase II was completed in April 2021. This phase included erosion repair along a 150-foot area just downstream of the first phase, and also included turf establishment.

Tree replanting took place during the 2021-22 season and included nearly 1,000 native species planted on the Pillot Gully slopes from Vintage Preserve Parkway to Cypress Creek. The trees included a mixture of native hardwood and pine trees, with a density of up to 300 trees planted per acre. Additionally, 65 larger trees up to 20 feet tall were relocated to and planted along the high bank and trail areas to re-establish the forested canopy more quickly.

At a public meeting in April 2019, the Flood Control District shared that tree impacts would be minimal in the project area. However, in addition to the repair of the bottom of the natural channel, it became necessary to repair the eroded side slopes of the channel all the way up to the high bank, and additional space within the right-of-way was needed to implement the project, resulting in a need to remove more trees. Also, after rain events in 2020, a smaller area downstream of the original project area was found to have significant erosion and was added to the repair contract.

Community Engagement Meeting

A Community Engagement meeting for this project was held on April 29, 2019

• Video
• Summary
• Presentation