HOH RIVER (Dec. 26, 2007) — Before 1970, the Hoh River flooded once or twice every 10 years. But since 1970, the Hoh River has flooded five or six times every decade. To protect roads and property from these floods, tons of large rock, called rip-rap, have been used to armor the river bank.
These emergency fixes have seriously degraded fish habitat in the Hoh River and the tribal and non-Indian sport fisheries it supports, say Hoh tribal representatives and local conservation groups.
“We know and understand that resources have to be protected, but we think it’s time to move toward more natural solutions that pose less harm to salmon and trout. Ultimately we would like to look for ways to move as many of the people, buildings and roads out of the river’s floodplain,” said Vivian Lee, Hoh tribal chairwoman.
Rip-rap speeds the river’s flow, eliminating resting pools important to fish. In addition, rip-rap prevents a river from creating logjams that are important elements in the creation of fish habitat. Over time, miles of rip-rap create a straight river channel devoid of the natural bends, eddies, and holes that help control flooding while providing places fish to rest, feed, and spawn.
“We think there is a balance to be achieved by pursuing more natural fixes, such as engineered logjams, as well as moving people and parts of the road out of harm’s way where it’s feasible,” said Mike Hagen, forester with the Hoh River Trust (HRT). HRT is a non-profit agency dedicated protect, restore and enhance river lands along the Hoh River for the benefit of dependent species, including healthy salmon and steelhead runs.
“The problem with the ‘cheaper, quicker’ fix is that it removes prime salmon and bull trout spawning and rearing habitat, and ultimately, only deflects the river’s energy to another area that will have to be addressed in the future,” said Tyler Jurasin, fisheries manager and biologist for the Hoh Tribe.
In just the lower 4 miles of river, one fourth of the river’s bank had been rip-rapped, according to a 2004 channel migration study conducted by Perkins Geosciences. Along the multi-jurisdictional Upper Hoh Road that leads to Olympic National Park’s Hoh Rainforest, an estimated 17 percent of 21 miles of river bank have been rip-rapped.
Rip-rap puts a straitjacket on the river channel, eliminating important fish habitat-forming functions such as side-channel creation and maintaining those with consistent water flow throughout the year, said Jurasin.
“Tourism and fishing are parallel economic engines out here,” said Jurasin. “But keeping the road open at the expense of fish habitat ultimately takes money from region’s fishing-based economy.”
The twin pressures of increased flooding and decreased spawning and rearing habitat could easily put fish populations on the Hoh in decline. “There’s a perception that the Hoh River is pristine, and that its fish populations aren’t vulnerable,” said Jurasin. “These fish are resilient up to a point, but we’re concerned about the cumulative effects of flooding and rip-rapping to protect homes, businesses and roads in the floodplain.”
The Hoh Tribe’s own tribal center and some tribal housing need to be moved out of the flood plain within the next 25 to 30 years. The Hoh River will slice right through the lower reservation in that time period according to a 2004 channel migration study. While the tribe could pursue the construction of huge levees to protect them, that would further harm fish habitat and have a prohibitive cost. The tribe is working to relocate government offices and housing out of the floodplain.
For more information, contact: Tyler Jurasin, fisheries manager, biologist, Hoh Tribe, (360) 374-6737; Mike Hagen, forester, Hoh River Trust, (360) 452-5640, firstname.lastname@example.org; Debbie Preston, coastal information officer, Northwest Indian Fisheries Commisson, (360) 374-5501, (360) 780-1295, email@example.com
History of peak flows on the Hoh River from the US Geologic Survey.