By Caitlin Bell
On Saturday, February 19, 2011, Gavin Powell and Matthew Miller climbed aboard an inflatable raft and set off down Walnut Creek, unaware that the flooded and fast-moving channelized river would prove to be too dangerous to handle. As the city of Walnut Creek mourns the loss of two vibrant, happy teenagers, residents look to the source of the tragedy: the channelization of the creek.
Bill Kier, a resident of Walnut Creek for more than 60 years, wrote a poignant letter in the San Francisco Chronicle. “Our hearts go out to the families” he wrote. “My heart aches, too, for the community for the loss of their creek… Reading the story of the boys’ deaths in a concrete channel with 20-foot vertical drops, you had to wonder what kind of crazed engineering had befallen Walnut Creek.” As more and more streams are channelized around the state and across the country, we must consider the impacts of hydro-engineering projects.
The modification of natural features is not done without reason. Indeed, hydro-engineering projects such as channelization or the installation of culverts are generally done to control natural hazards such as flooding or erosion that are impacting private or public property. Many of these projects are necessary to prevent the loss of land and even lives. But these projects also “harden” natural landscapes, making them foreign, unnatural, and off-limits to humans.
Current global environmental trends point to a stormy future. Typically, cities have dealt with increased precipitation levels through the use of engineered solutions. However, employing natural methods to control flooding is also an option. Increasingly, municipalities are choosing to return the landscape to a near-original state and allow nature to reactivate its flood control system. “Daylighting” enclosed culverts may not be an option in all situations, but when possible, restoring a creek to a more natural state not only redirects control to a time-tested, natural system, but also gives residents a chance to reconnect with part of their community.
Creek restoration is an expensive and labor-intensive process that may or may not prove to be effective in addressing environmental hazards. In today’s economy, many urban planners are hard-pressed to justify the removal of existing culverts and channels. But as the economy improves and as older structures become expensive to maintain, opportunities will arise to choose a different, more natural path to flood control. It is critical for communities to seize these opportunities, and take a more holistic approach to urban planning. By including recreation and aesthetics in our design plans, we can hope to gain back our lost connection with nature, and avoid future tragedies.
Editor’s Note: After the publication of this article it was brought to our attention that Contra Costa County has begun to develop a public outreach campaign to educate citizens about the hazards of channelized creeks during periods of flooding. The Public Works Department has also addressed these dangers with a 50-year plan for the county’s existing engineered structures, which can be viewed via the link below.
Photos: Channelized stretch of Los Angeles River; Sausal Creek Daylighting Project, Portola Valley; Strawberry Creek Daylighting Project, Berkeley.