“HY-DROL-O-GY!” That was the cry from our oarsman, Drew, as he plowed our raft through Redneck rapid on the Colorado River in the Grand Canyon this fall. I was 100 percent drenched inside and out by the time we were through and a little cold, but I was grinning ear to ear as my heart warmed to hear a cry of delight about water in action.
Drew was curious about us passengers and when he learned I was a hydrologist it must have struck a chord. As a professional river runner he immediately related to the science of water, though his experience was in applied fluid dynamics and hourly experiments involving laminar and turbulent flow. Not my specialty, to put it mildly.
Even so, Drew’s spontaneous call became my mantra, whether shouted or chanted just-to-me, as our boatmen navigated around exposed boulders, crashing through riffles and rapids, holes and pour-overs.
And when the river was slow and full of swirling eddies reflecting the sunlit walls of narrow Marble Canyon, I was reflecting on the appearance of grace in a relatively small river that provides so much for so many.
From her headwaters in the mighty Rockies to the trickle that occasionally enters the Sea of Cortez, the Colorado River provides water supporting the desert ecosystem, supplies people in their homes, industries, gardens and mega-farms, and generates hydropower for millions.
Unfortunately, drought and humanity’s unquenchable thirst for her many capabilities has stretched the Colorado River thin. Both Lake Powell and Lake Mead reservoirs are anorexic as well, with little hope of ever returning to a healthy condition.
Of course, providing the opportunity for tourists like us to recreate, study, relax and generally find enlightenment is yet another of the Colorado’s capacities. (Was it my imagination or was Drew making sure my seat on the front left raft tube got the full splashy benefit of every rapid?)
We and our rafting trip mates had thought we were there to enjoy the river and the glorious canyon it carved out of rocks billions of years old. But, with enlightenment comes awareness.
Sisters in spirit
As my hydrologically-oriented brain contemplated the volume of water our rafts floated upon, I marveled that the Colorado River’s flow at that time, only 7,000-8,000 cubic feet per second (cfs), was a similar volume to the highest storm flows in our own Dungeness River — despite the vastly different scale of the two drainages.
The upper Colorado basin spans four states and includes dozens of dams that release water as needed for the uses listed above. Specifically in the Grand Canyon, her flow volumes are regulated at Glen Canyon Dam primarily to meet daily and seasonal demand for electricity. Peak season is when the demand for air conditioning to relieve the desert heat is highest, and dam releases are two to three times the volume released in the fall.
Continued drought threatens huge releases from shrinking reservoirs, causing concerns for electric grid reliability in the metropolises of Pheonix and Las Vegas.
By design, dams regulate flow in rivers, so flow in the Grand Canyon fluctuates very little relative to an unregulated river like the Dungeness. High flows in the Dungeness are two orders of magnitude higher than low flows.
Indeed, last month the Dungeness was down to 75 cfs, exposing her cobbly bones and allowing little opportunity for salmon to migrate upstream.
The very short, steep Dungeness River has no dam* so her flows reflect what’s happening with the weather each season: rain in Winter, snowmelt in Summer, and flow from springs releasing groundwater in fall. Naturally fluctuating flows move the cobble substrate and woody debris in a river’s channel, providing good habitat for fish and wildlife. A naturally broad floodplain and tributaries provide space to accommodate floodwaters and opportunity for recharge and discharge to/from the water table.
Of course, the actual amount of water in the Dungeness River at a given point also reflects diversions for irrigation and the cumulative impact of withdrawals from thousands of shallow wells hydraulically connected to the river underground. Direct uses and demand for Dungeness water peaks when farmers and others need to irrigate, which also happens to be when certain runs of salmon are returning to spawn.
Like the Colorado in its Grand Canyon, the Dungeness looks full of grace as she courses through our countryside. But she is stretched thin by climate change and human actions as much as any river in the U.S. West: by diminishing snow reservoirs in the mountains, by increasingly intense storms, by levees and invasive weeds encroaching on her floodplain, and by a high demand for water when her flows are lowest.
Whether gazing at a serene Dungeness in late summer or a raging torrent in winter, remember the mantra “Hy-drol-o-gy!” and marvel at the gracefully intricate ways our river provides for so many.
The 2022 water year ended on Sept. 30, but it was another month until fall rains began and our rivers began to rise. The normal start of salmon fishing season in the Dungeness River was postponed to avoid further stressing fish migrating upstream in very little water.
The highs and lows in the Dungeness for the 2022 Water Year (Oct. 1, 2021-Sept. 30, 2022):
• At the upper/USGS gage at river mile 11.2, the highest average daily flow was 2,900 cfs on Nov. 15, 2021; the low was 94.5 cfs on Sept. 28, 2022.
Extremes at the USGS gage for the period of record (1923-current year, minus seven years during the Depression):
• Maximum daily flow, 7,610 cfs on Jan. 7, 2002; minimum daily flow, 61 cfs on Nov. 23, 1993, “a result of freezeup.”
USGS gage Colorado River above Diamond Creek (Grand Canyon):
• Flow during our trip ranged between 7,300 and 12,500 cfs with a daily flux of 2000 cfs.
• Mid-summer flow ranges between 10,000-15,000 cfs with a daily flux of 3000 cfs.
*Clallam County is leading the Dungeness Off-Channel Reservoir project on River Road, designed to help meet irrigation water needs in the late summer low-flow season; an Open House on the project is planned for Dec. 6.
Ann Soule is a semi-retired hydrologist immersed in the Dungeness watershed since 1990, reporting water news intermittently. Now she is Resource Advisor for City of Sequim part-time; any opinions expressed are hers and do not represent policies of her employer. Reach Ann at firstname.lastname@example.org or via her blog at www.watercolumnsite.wordpress.com.