A cubic-foot-per-second (cfs) is a measure of stream flow equivalent to about 7.5 gallons passing a point each second. It’s 450 gallons each minute and 650,000 gallons in a day.

If 12 inches of water happened to be flowing that fast in a 12-inch square channel then, one imagines, a decent-sized salmon could swim through it.

This visualization of flowing water is handy when talking hydrology with, say, farmers. Farmers often use gallons per minute and acre-feet or acre-inches to express volumes of water needed to grow various crops. Such as, hay pastures require 18 inches per season but raspberries require 24 inches, regardless of acreage.

Back to that salmon that may swim in a square channel but certainly won’t spawn in one. A few necessities for a salmon stream bed include enough space and gravel to build a redd (egg nest), enough pools to escape predators and fishing lures, and enough shade and cascades to keep the flow cool and oxygenated.

Multiply these needs by hundreds or thousands of fish and you can imagine the size of river needed to support a healthy population: many miles and plenty of water.

So, how much is ‘plenty’?

It wasn’t long ago that the Dungeness River supported many runs of sea-going salmon, from Chinook in spring/summer and Chum, Coho and Pinks in the summer and fall, plus winter and summer steelhead and bull trout year-round. All populations are now struggling, including Coho supported by a hatchery.

In the 1990s, biologists studied the River and established that low stream flow in late summer is one of the most significant limiting factors for Dungeness River salmon survival. Given that water rights granted a century prior to farmers gave them legal authority to completely de-water the Dungeness, conversations between biologists and those diverting River water for irrigation suddenly became more direct and focused.

Fish biologists said stream flow in the mainstem Dungeness should be between 40 and 340 cfs for salmon migrating in late summer to spawn and successfully complete their life cycle—and preferably never be less than 180 cfs. Chinook, the most threatened with extinction and thus the highest priority species, utilize river side channels to spawn—which means flow needs to be high enough for water to spread from the mainstem into channels.

With this information, and the knowledge that summer flows often drop well below those levels in dry years, farmers and other stakeholders immediately recognized an untenable situation. It’s a horrific lose-lose if salmon populations go extinct. The parties debated within the context of “shared sacrifice” and irrigation managers agreed to avoid diverting more than half the flow, or more than what would cause the mainstem to drop below 60 cfs. River flow measurements would be taken at the U.S. Geological Survey gauge upstream of all diversion points.

Over a decade later, 180 cfs became the minimum flow level for late summer set by Rule in WAC 173-518 (the Dungeness Instream Flow and Water Management Rule). As of Jan. 2, 2013, new water rights are not allowed to impair that flow.

At the time the Rule was finalized in 2012, the irrigators’ informal agreement became formal. Regardless of the seniority of their water rights, irrigators agreed to cut back to help salmon. When flow drops to 120 cfs, they reduce diversions at head gates and take less than half to avoid the level dropping below 60 cfs. If their crops need water, farmers must manage with less.

In eastern Washington, river flows are already low enough that hundreds of irrigators have had their junior water rights curtailed by the state due to shortages felt by senior water right holders.

On Monday, the Dungeness was flowing below 180 — and our farmers are no doubt very aware.

On the brink of drought

Water supplies are limited – but only in time, very

esoterically speaking. True, what people use now is recycled from what was used before, somewhere on this planet. But environmental and socioeconomic demand can’t wait that long and rarely is there the technologic and financial ability to move it from far away to where it’s needed.

Three months ago our snowpack looked pretty solid. Now it looks gone.

To offset the hardships of drought conditions, more of us besides farmers and river protectors should join in the shared sacrifice. Many public water systems on the Olympic Peninsula have now issued requests to voluntarily conserve water. Private well owners are encouraged to heed the same request.

Everyone using water – especially outside – has a role to play, in times like these.

Geek moment

Cooler temps and slight precipitation in the first days of August were welcome relief from a near-record-hot July. Due to the high rate of snow melt, the Dungeness River is one of many in the state flowing lower than normal.

As of last week, the very southwestern section of Washington State already has a “Severe Drought” classification from the U.S. Drought Monitor. The Sequim area is currently classified as “Abnormally Dry.” Soils and vegetation are stressed from extended dryness — exacerbating risk of wildfire.

The U.S. Water Watcher tracks five “flavors” of drought (an ironic metaphor with ice cream):

• Meteorological Drought — a period of low precipitation.

• Hydrological Drought — a period of low water supply in reservoirs, streams, and groundwater.

• Snow Drought — a period of abnormally low snowpack.

• Agricultural Drought — when crops experience a negative water balance, for instance when plants lose more water through evapotranspiration than they can absorb from the soil.

• Ecological Drought — a deficit in surface water supplies that detrimentally impacts an ecosystem.

Odds are in favor of above-average temperatures through October, and there is a 70 percent chance of another El Nino with relatively warmer temperatures this winter.

The USGS stream gauge is located in a canyon 11.2 miles upriver from the mouth. Flow measurements have been made at the site for almost 100 years, and are now telemetered and reported real-time at

For the 2018 water year (started Oct. 1, 2017):

• At Sequim 2E weather station (elev. 25 feet): Cumulative rainfall = 19.2 inches (above normal); Most rainfall in 24 hours = 1.14 inches on Dec. 18; Highest temp = 85 deg F on July 14

• At the USGS gage on the Dungeness River (Mile 11.2), Highest flow = 2,980 cfs on Nov. 23; Lowest flow = 101 cfs on Oct. 16, 2017. Range for the past month is 180-400 cfs (cubic foot per second)

On the morning of Aug. 6, 2018:

• Dungeness River = 180 cfs, 65 percent of the long-term average for this date (and the minimum flow level recommended to sustain healthy salmonids — see article above)

• Bell Creek at Carrie Blake Park = dry; at the mouth at Washington Harbor = about 1 cfs.

Ann Soule is a hydrogeologist immersed in the Dungeness watershed since 1990, now Resource Manager for City of Sequim. Reach Ann at columnists@sequimgazette.com or via her blog at watercolumnsite.wordpress.com.