A sanctuary for salmon

Engineering solutions to restore habitat without reversing development

Years of development, logging and farming have created inhospitable environments for salmon species in some western Washington's waterways. The combination of rising water temperatures, more frequent flooding, blocked access, pollution and increased levels of sedimentation have spelled disaster for some of the salmon that used to fill our rivers and streams.

Puget Sound chinook salmon will likely be joined on Endangered Species Act lists by other species within the year. Whether they're threatened, endangered or just holding steady, we need to find new ways to protect salmon.

While restoring entire river basins is a lofty goal, it requires large amounts of capital, significant political commitment and can take many years to implement. In the meantime, we can have the most immediate and positive effect on salmon populations by creating and enhancing off-channel habitat.

As engineers we know that practical solutions can and should be implemented in order to accomplish the goal of species restoration. Wholesale demolishing of infrastructure is not an answer, and we can't afford to stop building infrastructure while we study the problems. We need cost effective solutions that can be set in motion immediately. To that end, Consulting Engineers Council of Washington has sought out volunteer opportunities such as a recent project with Long Live the Kings.

The Wishkah off-channel at Darrin's Pond.

Due to logging over the years, the Wishkah River is extremely susceptible to flooding. There have been, for example, five major floods in the last four years. Because restoring the river to fully functional habitat would take countless years and dollars, Long Live the Kings is focusing on creating off-channel, over-wintering habitat and rearing areas for salmon.

Darrin's Pond is an existing beaver pond that had been fed by a small stream that exited into the east fork of the Wishkah River. Landslides in 1997 and 1998 diverted the stream channel, and, as a result, the pond dried up during the summer months and became filled with invasive vegetation. Through the partnership with CECW, the landowners and the U.S. Fish and Wildlife Service, Long Live the Kings was able to restore water to the pond and recreate habitat for up to 2,000 smolts per year.

By restoring the creek to its pre-landslide course and building an engineered outlet channel to bypass the beaver dam, Long Live the Kings created a year-round water supply to the pond and a route for juvenile fish to reach it. The half-acre pond provides a refuge for fish during floods and high winter flows in the river when silt, sediment and debris often create unsuitable conditions for fish survival. The engineered access channel provides a passage around the beaver dam through a series of log weirs. The log weirs create a series of small steps from the river to the pond, rather than one large step at the beaver dam. Additionally, the weirs prevent the pond from draining lower than desired when stream flows are low in the summer. The logs are keyed into the bank of the channel and armored with rock to minimize erosion during high flows. The channel winds through the maple and alder forest that surrounds the pond providing a shady corridor for fish migration.

Although the success of Darrin's Pond is not yet measurable - monitoring began on Oct. 15, 1999 - it is indicative of the kinds of efforts that we can and must continue to make to recover and protect our fisheries without rolling back existing infrastructure.

The project at Darrin's Pond, along with two other off-channel habitat projects and a spawning channel completed this summer by Long Live the Kings, are every bit as important as the larger efforts being tackled by government agencies. These projects, whether in rural areas or urban environments, will be most successful when certain criteria exist. Most important is a naturally occurring supply of fish so the project will enhance existing populations. Other criteria that improve the chances of the success of a project are a year- round supply of water, a stable drainage basin and mature vegetation. In urban areas, it is also crucial to have a population that cares about the stream or river and is willing to take action toward its restoration.

Recovering wild salmon in the Pacific Northwest is far too large an undertaking to rely solely on government actions to accomplish. We will need to see the gamut of projects from multimillion dollar public efforts to hundreds if not thousands of small, privately organized and funded projects throughout the next decade. While highly visible urban projects will serve to educate the public and impact how we plan for and build in the future, when measured in terms of the numbers of fish, our greatest successes will come from the combined results of many small projects like the one at Darrin's Pond.

---

djc home | top | special issues index