Projects & Studies
Drainage Maintenance Projects Nearing Completion in Kingwood
Trees to be Planted on Bens Branch Tributary
In late 2014, the Harris County Flood Control District was scheduled to begin planting nearly 500 loblolly pine, bald cypress, American elm, water oak and other tree species along a Bens Branch tributary in Kingwood as part of the Flood Control District’s 2014-15 Tree Planting Program.
The tree planting in Kingwood was to follow completion of four maintenance projects aimed at repairing significant erosion and removing sediment from sections of Bens Branch and its tributaries. This work restores the channels’ ability to convey stormwater and will help prevent future erosion.
The four maintenance project sites, encompassing approximately 12,000 linear feet of channel, included:
- Bens Branch, formally identified as HCFCD Unit G103-33-00, from Woodland Hills Drive upstream to Northpark Drive.
- An unnamed Bens Branch tributary formally identified as HCFCD Unit G103-33-02, from its confluence with Bens Branch upstream to Northpark Drive.
- An unnamed Bens Branch tributary formally identified as HCFCD Unit G103-33-03, from its confluence with Bens Branch upstream to Hidden Pines Drive.
- An unnamed Bens Branch tributary formally identified as HCFCD Unit G103-33-01, from its confluence with Bens Branch upstream to Northpark Drive.
Harris County Commissioners Court approved a $1.13 million contract with low bidder Lecon Inc. to perform the maintenance work, which began in late November 2013 and was to be completed by late 2014. Depending on the specific site, the projects repaired severe to moderate erosion, removed silt that had built up in the channels, repaired or replaced approximately 50 damaged stormwater and interceptor outfall pipes, and replaced failed concrete slope paving.
Erosion is caused by a combination of poor soils and the movement of stormwater in a bayou or other channel. It can cause a channel’s side slopes to degrade and eventually to fail. It also can lead to a buildup of sediment in the channel, which can affect the channel’s ability to convey stormwater. Interceptor swales are shallow ditches located along the top of the channel slopes. These swales direct the flow of overland stormwater into the channel via outfall pipes, to prevent further erosion.
At some locations, to allow for maintenance repairs, it was necessary to clear trees and brush and remove encroachments such as fences from Flood Control District right of way. Along a portion of G103-33-01, workers removed a 10- to 12-foot strip of trees and brush that had grown into Flood Control District property. The goal was to restore maintenance access to the right of way, so that workers could replace failed interceptor structures and regrade the backslope swales and maintenance berms.
As part of this year’s Tree Planting Program, which runs October through March, Flood Control District foresters evaluated G103-33-01 and identified appropriate locations for planting once construction was complete. Starting at the southern end of the channel, near the Creekwood Nature Area and the confluence with Bens Branch, trees will be planted in groups at the top of bank and upper portions of the slope, and also in areas that serve as a buffer between the channel and adjoining Bear Branch Trail Association hike and bike trails. Trees are typically planted along the upper third of channel slopes to avoid impeding the flow of stormwater, and to allow access for maintenance vehicles and equipment. Areas containing outfall structures will be avoided.
Planting along the northern end of the tributary will proceed as construction allows. Other species on the planting list include bur oak, sycamore, Shumard oak, red maple, southern magnolia, river birch and red bud. The trees typically will be fertilized, watered and mulched during a two-year establishment period.
Since 2001, the Flood Control District’s Tree Planting Program has added more than 200,000 trees to 195 flood control sites across 1,043 acres in Harris County. This year alone, the Flood Control District will plant approximately 12,500 trees on nine channels, at two stormwater detention basins and in two neighborhoods where flood-prone homes have been purchased and the land cleared as part of the Flood Control District’s Voluntary Home Buyout Program.
Trees in appropriate locations can complement the Flood Control District’s mission of “providing flood damage reduction projects that work, with appropriate regard for community and natural values.” Mature trees and their web of roots help reduce the risk of erosion in drainage channels. Trees also create a shade canopy that reduces mowing costs, provides wildlife habitat, and improves water quality by dissipating erosion-causing rainfall.