Puget Sound Recovery Region – Water Summary
The Water Quality Index (WQI) is designed to rate general water quality based on monitoring conducted by Washington Department of Ecology’s Freshwater Monitoring Unit. Please read the overview to learn more about the index and its limitations. The Water Quality Index for rivers and streams combines eight measures of water quality. Expectations for four of the measures (dissolved oxygen, pH, temperature, and fecal coliform bacteria) are tied to the State’s Water Quality Standards. The other four measures (nitrogen, phosphorus, suspended sediment, and turbidity) do not have specific numeric standards. Note that toxic contaminants including metals and pesticides are not evaluated as part of this index.
Index values are based on monthly monitoring at individual stations. Index values range from 1 – 100 with higher numbers indicating better water quality. Again, note that stations can have good WQI scores but still be impaired by something other than one of the eight constituent WQI measures (e.g. toxics).
In Puget Sound, the lowest stream flows occur during the summer when there is less rain and warmer temperatures. Summer low flow is measured as the 30-day minimum water flow at river and stream gaging stations.
The indicator tests whether the long-term trends of annual summer low flow levels are declining or increasing. The trend test uses data collected since 1975, representing more than 35 years of measurements. The advantage of a long-term data set is that the influence of annual weather differences and cyclic climate changes (e.g., el Niño and la Niña; or the phases of the Pacific Decadal Oscillation) are minimized over time. Because trends are measured over decades, this indicator is not sensitive to relatively short-term changes occurring over just a few years even if significant flow restoration occurs. To measure a change in trend, either large changes in flow must occur (such as a dam setting minimum downstream flows), or a very consistent change over a long period of time is needed.
Insert photo from signing of WRIA 18E instream flow rule? [Get this from DOE]
There is a history of over-appropriation of water in the Dungeness River, and the resulting stream flow issues, along with other factors, have stressed the river’s fish populations. Dungeness River Chinook are one of two populations in the Strait of Juan de Fuca biogeographic region that need to get to low risk to meet Evolutionarily Significant Unit-wide (defined below) recovery (Elwha River Chinook being the other). Currently, there is an annual return of only 100-200 wild Dungeness adult Chinook salmon along with 300-400 hatchery Dungeness Chinook adults. This is far short of the planning targets listed in the Puget Sound Salmon Recovery Plan, and also falls short of goals for a harvestable stock. Monitoring from the Washington Department of Fish and Wildlife shows juvenile Dungeness Chinook survive from egg to smolt stage at a very low rate when compared to other populations.
Under local leadership, the area has been able to work together to make significant progress on key in-stream flow policy issues. In 2012, the Washington Department of Ecology signed an agreement with irrigators in the Dungeness watershed that will help protect future water supplies for agriculture. The agreement also will help ensure there is adequate water in the Sequim area for economic development and fish habitat.
Ecology Director Ted Sturdevant signed the agreement with representatives of seven irrigation companies. The agreement is considered a key part of a water management rule Ecology approved in November 2012 for the Dungeness watershed. The agreement secures water supplies for current and future uses in the Sequim area for the benefit of people, community development, agriculture, and fish. The rule goes into effect January 02, 2013.
NOTE: For Pacific salmon, the National Oceanic and Atmospheric Administration’s National Marine Fisheries Service uses an evolutionarily significant unit (ESU) as its definition of species under the Endangered Species Act. An ESU is a population or group of populations of salmon that is substantially reproductively isolated from other populations and contributes substantially to the evolutionary legacy of the biological species.
The North Fork Stillaguamish shows poor water quality, particularly related to total suspended solids, turbidity, and nutrients (nitrogen and phosphorus). Sediment loading from landslides and logging roads continue to be a problem. The North Fork shows a strongly decreasing trend in water flow. Water flow and water quality are a concern for fish, particularly listed Chinook salmon, because populations are low. Increasing peak flows on the North Fork Stillaguamish, which can wash away spawning gravels or bury eggs and young fish, is also a concern for Chinook. The South Fork Stillaguamish, which also shows relatively low water quality scores, is used by a Chinook stock with extremely low population numbers, maintained in part by a hatchery supplementation program.
In the Snohomish River Salmon Conservation Plan, water quality and summer flows are identified as an issue in a variety of subbasins. Although the Raging River is a core spawning and rearing area for multiple migrating salmon species including Chinook, coho, and steelhead, the strongly decreasing water quantity trend in the Raging River has not yet been identified as a focal issue. However, high water temperatures in the Raging River in the late summer continue to be a concern, as reported in the Snoqualmie River Water Quality Synthesis Report (reference below). In fact, summer temperatures in the lower Raging River were found to be the highest of any river or stream in the Snoqualmie Watershed. The South Fork Snoqualmie River is upstream of Snoqualmie Falls and is the smallest of the three major forks; therefore, decreasing flow trends are not considered a primary concern for ocean-going fish, such as Chinook. However, if these flow trends are found to be occurring throughout the watershed, then impacts to migrating fish in the lower river will merit greater concern.
NOTE: Kaje, J. 2009. Snoqualmie Watershed Water Quality Synthesis Report. Prepared for the Snoqualmie Watershed Forum. King County Department of Natural Resources and Parks, Water and Land Resources Division. 180 p
More Stories Around the Sound
In the more urbanized areas of Puget Sound, polluted runoff from buildings and paved surfaces are a major contributor to poor water quality and a significant threat to salmon. The Puyallup River water quality scores are some of the lowest of all the Puget Sound rivers sampled by the Department of Ecology. However, the City of Puyallup is making a major effort to reverse this trend.
Green infrastructure projects such as the use of pervious pavement and rain gardens are one way that a growing number of jurisdictions and their partners are reducing the amount of pollution reaching Puget Sound’s rivers and streams. Pervious paving and rain gardens allow storm water to soak into the ground rather than rushing untreated down a pipe into the nearest water body. Recent research by the Washington State University’s Low Impact Development Research Program dramatically demonstrates the difference that rain gardens can make for the survival of juvenile salmon. During a storm after a long dry spell, researchers collected rainwater running off the highway. They filtered half of the polluted water through soil columns that mimicked a rain garden and left half untreated. Then they put juvenile coho salmon in the treated and untreated water. Within 12 hours the salmon in the untreated water were all dead while the salmon in the rain garden treated water survived. Learn more.
For a story on use of rain gardens in the City of Puyallup to project water quality and regulate water quantity through recharging groundwater, see the State of the Sound’s “Rain Gardens to the Rescue.”
For a story on the an innovative strategy to protect water quality and increase water supplies in the Nisqually and Snohomish Watersheds through watershed services transaction projects, see the State of the Sound’s “How Much is Water Worth”.