Country Club Armors High Banks with Chunks of Rubble
August 12, 2015
For months we watched with suspense the towering piles of concrete riprap. They hung heavily over the edge of a high bank on the south side of Buffalo Bayou near the downstream end of one of the loveliest natural stretches of the bayou in the city. It’s a long stretch of the bayou that the Harris County Flood Control District wants to bulldoze and “restore” to a “more natural state,” so we were apprehensive.
A row of small telltale colored flags had first appeared near the waterline here and upstream at the upper limit of the area targeted for flood control’s highly destructive Memorial Park Demonstration Project.
The south bank of the nearly 1.5 mile project area is owned by the River Oaks Country Club, which is a one-third partner in the $6 million public project initiated and promoted by the Bayou Preservation Association. The club, which has nearly completed a renovation of its golf course on the bayou, had long threatened to armor its banks with riprap if the “stabilization” project didn’t go through.
And now the club has carried through on its threat, laying down black plastic sheeting on the steep banks at those two locations downstream and upstream, distributing chunks of concrete on the slopes, and covering the blocks with dirt. Club member Steve Lindley, who is overseeing the riprap work as well as the golf course upgrade for the club, said that the plastic sheeting is porous and biodegradable and that club plans to seed the dirt with grass to keep it from washing away and eventually to plant it with native vegetation such as chili pequin.
Most of the north bank of the project is public park, including the natural banks of Memorial Park and the Hogg Bird Sanctuary, which would be largely destroyed by the project along with the bayou’s ecosystem. The district’s plan is to scrape some 80 percent of the riparian forest, grade and level the banks including high, very old cliffs and ancient sandstone ledges, and replant them with grass and other things still in the planning. The district would dredge, re-route and deepen the bayou (a section never before channelized), fill in a beautiful meander and cut a new channel through the forest, shortening the bayou.
Still Planning to Participate in the Bulldozing Project
Lindley said the club is still planning to participate in the flood control project, should the project ever receive a permit from the Army Corps of Engineers. The riprap armoring of the banks, which is one of the most environmentally damaging methods of erosion control in addition to being really ugly and unnatural, is only temporary, said Lindley. If necessary, the concrete chunks can be reused in the demonstration project, Lindley said.
In its revised permit application to the Corps, the flood control district says that “… isolated bank armoring installed to deflect the erosive shear stress at the point of failure, in most cases, is scoured at one or both of its terminal ends, resulting in eventual failure. This type of armoring redirects stream energy to a new location downstream, creating a new point of stress.” (See page 3.)
The Negatives of Concrete Riprap
Here are some of the other negatives of riprap:
- May increase potential for flooding and washout downstream because riprap may speed up flow, rather than absorbing water’s energy and slowing it down.
- Can cause problems for other landowners by deflecting the current against opposite or downstream banks and initiating new erosion.
- Destroys natural vegetation and habitat on the bank.
- Cannot absorb pollutants entering stream from runoff.
- Vegetation is difficult to establish among rocks.
- Riprapped banks absorb heat and cause water temperatures to rise, particularly on smaller streams, adversely affecting stream habitat.
- Unnatural appearance.
- Placement by machine can cause significant disturbance to the sediments and bank soils.
The Corps of Engineers is considering whether to grant a permit application for the project. In order to protect the health of our waters, under the federal Clean Water Act the Corps is responsible for projects that would dredge or fill navigable waters below the Ordinary High Water Mark, their tributaries, and adjacent wetlands.
Some of the club’s riprap and dirt appears to have fallen to the water’s edge, if not into the water, at very low flow, which would appear to be below the Ordinary High Water Mark. There are also wetlands near the foot of the banks being armored.
However, Lindley said the club was careful to keep the armoring above the Ordinary High Water Mark.
Jayson Hudson, regulatory project manager for the Galveston District office of the Corps, said he had referred Save Buffalo Bayou’s concerns to Kenny Jaynes, chief of the compliance branch for the Galveston District. Jaynes has not yet responded.
The Loss of the River Oaks
The high banks on the south side of the bayou were heavily forested until several decades ago when the country club began clear-cutting the mature trees and expanding the golf course up to the edge of the banks, mowing and watering the grass, and building a concrete path close to the edge for motorized vehicles. In the last year, in preparing for the renovation of the golf course, the club killed off most of the grass, including some remaining vegetation on the high banks now being armored, and began running heavy equipment over the grounds, including the high banks.
Unfortunately all of these activities violate Best Management Practices for riparian zones and likely helped to destabilize the high banks.
Watch a slide show of the evolution of the south bank of Buffalo Bayou in the proposed project area over the years.