Water column: An annual look at our water

The end of September is the end of the fiscal year for many, including our federal government. It also happens to be the end of the official water year for Western states because October is when accumulation of water “revenue” and other assets begins.

If we adopt the financial tradition of preparing an Annual Report — but for water in the Dungeness — we can answer, did we end 2021 in the red or in the black? Are we in a strong position going forward, offering confidence to stakeholders and potential investors?

Revenue

First, the good news. Revenue really picked up at the end of the second quarter (a.k.a. winter, from January to March). Snowpack was more than 250 percent of normal on April 1, the date considered to represent maximum accumulation in the mountains.

The water year was looking rosy at that point, but let’s do the numbers:

• Rainfall in the mountains: 40.8 inches, or 88 percent of normal; not too bad, so it seems.

• Rainfall in the lowlands: 18.9 inches, or 115 percent of normal. Looking better!

Sensibly, some of that income was reinvested in reservoirs of water that pay dividends in the fourth quarter (a.k.a. summer).

• Snowpack and glaciers at the top of the Dungeness watershed melt in late spring and summer, feeding area streams:

The Dungeness SNOTEL station (Silver Creek ridge, elevation 4,010 feet) reported 30 inches of snow and 13.6 inches of “snow water equivalent” (SWE*), 252 percent of normal.

The Deer Park monitoring station (top of Blue Mountain, elevation 5,346 feet) reported 55 inches of snow and 18.3 inches of SWE, about 110 percent of normal.

Clearly, it was a skookum year for revenue!

Ignored in most financial reports, here’s what we know about water income obtained underground:

• We don’t actually measure how much precipitation infiltrates into the aquifer, but Sequim-area soils are so porous in many areas that water managers can profit from intentionally recharging the aquifer system by, for example, running diverted River water through abandoned irrigation ditches.

• Runoff from streets, driveways and roofs (a.k.a. stormwater) is infiltrated in drywells and perforated pipelines to avoid loss of rainwater revenue to the sea.

Expenditures

Like money, water flows through a myriad system of channels, in all directions, withdrawn for use and consumption … and even evaporating at times.

Unlike money, water is a renewable resource, provided you can wait long enough for the water in our bodies and used by our industries to cycle back and be cleaned and usable again as water.

Certain channels have flow gages:

• The volume of water flowing out of the mountains into the Dungeness River for the entire water year was 244,000 acre-feet**, measured upstream of all diversions and Canyon Creek.

• The flow into marine water was 226,000 acre-feet, measured near the River mouth at Schoolhouse Bridge.

The difference, about 18,000 acre-feet, is accounted for by inputs from tributaries and springs minus outtakes by seepage and irrigation diversions.

• Irrigation managers report the average annual amount diverted from the River into their canals is around 12,400 acre-feet, allowed by their senior water rights permits from April 15-Sept. 15.

Water consumption by people and farms in the Dungeness watershed on an annual basis can be estimated fairly easily. Here are some approximate numbers:

• About 90 percent of the 12,400 acre-feet diverted by irrigators is “consumed” by farm crops and domestic landscaping, but some is consumed by stock animals and some seeps into the ground — though most of the largest leaks have been piped in recent decades.

• Wells pump groundwater to the surface for human uses:

> In a typical year the City of Sequim’s water system delivers around 1,300 acre-feet of water for residential, commercial, and some industry and irrigation uses inside its service area.

> Domestic wells in the watershed outside the Sequim city limits pump another 2,500 acre-feet in a typical year.***

Note, however, some of the water pumped from aquifers returns to the watershed:

• According to state policies, 90 percent of the groundwater used domestically is considered aquifer recharge if the home is on a septic system that infiltrates into the water table.

• Water originating from the City’s drinking water system is mostly treated and recycled and, for at least half the year, returns to the watershed to irrigate playfields and landscaping.

Finally, evaporation and transpiration by plants are not measured but we could consider these factors “a few bucks and change,” especially since that water is never lost to the system completely.

Extreme heat

Of course, record-breaking heat in late June was the big story of the 2021 Water Year.

Mother Nature’s April Fools’ Day “gotcha” played out two months later when extreme heat thawed and thinned the thick snow blanket in the mountains. From town we watched, helplessly, as the white blanket on our brown peaks all but disappeared in three days.

Continuing the metaphor, you could call it a market crash. In a very short time, the value of reserved assets plummeted.

By late August irrigators had to cut back on diversions, trading off who got water when, and some had to forego irrigation altogether. Because the drought of snowmelt had not been anticipated, state managers had not set up options to pay farmers to not exercise their water rights (“water leasing”), like they sometimes do when they know low flows will affect the ability of salmon to migrate upstream in late summer.

By September, emergency measures were taken by some to assist migrating salmon, including capture and transport to the Dungeness hatchery and moving rocks by hand to deepen constricted channels of the River.

Unfortunately, meeting everyone’s need for water in times of a warming planet is much more complicated than the economics of the free market.

Our annual report for the 2021 water year must conclude, yet again — we’re in the red, and bleeding.

Geek moment

The highs and lows in the Dungeness River from the 2021 Water Year:

• At the upper/USGS gage, the instantaneous high flow in winter was 2,720 cfs (cubic feet per second) on Jan. 13, 2021. The high flow from snowmelt was 1,160 cfs on June 28; the low was 78.6 cfs on Sept. 17.

• At the lower/Ecology gage the winter-time high flow was 2,820 cfs on Jan. 13. The snowmelt high was 1,070 cfs on June 28 and the low flow was not captured but estimated to be around 60 cfs on Sept. 17.

Ann Soule is a hydrologist immersed in the Dungeness watershed since 1990, reporting water news on a seasonal basis. Now the Resource Manager for City of Sequim, any opinions expressed are the author’s and do not necessarily represent policies of her employer. Reach Ann at columnists@sequimgazette.com or via her blog at www.watercolumnsite.wordpress.com.

* — “Snow-water equivalent” is a conversion of snow depth to its liquid water equivalent, based on density

** — An “acre-foot” is what it sounds like: the volume equaling 1 acre by 1 foot tall. The upper gage is maintained by the U.S. Geological Survey and the gage near the mouth is kept up by Washington Dept. of Ecology

*** — 2,500 acre-feet annually is around two million gallons per day, roughly estimated based on a population of 30,000 times 150 gallons per day per household, at 2.4 persons per household