Glen Canyon and Hetch Hetchy Valley
Reservoir levels have dropped as a result of the drought gripping much of the American West. In California, the phenomenon is recent as reservoirs were generally full in 2019. Storage levels in the Colorado Basin, however, have been dropping steadily for some time.
No place is this more evident that in Glen Canyon, where Lake Powell is at the lowest level in decades. Glen Canyon Dam was completed in the mid-1960’s when few had seen the area. The dam is the bane of many desert lovers, including author Edward Abbey who fantasized about blowing it up in The Monkey Wrench Gang.
This week’s New Yorker includes a wonderful article on the history of Glen Canyon and the many folks who are exploring the area and are able to access places that have been underwater until recently.
Glen Canyon and Hetch Hetchy Valley share at least two things in common. First, both are wonders of nature that were destroyed by controversial water storage projects. Second, both projects provide only modest contributions to regional water supply.
Geographically, Glen Canyon and Hetch Hetchy Valley are very different. Glen is a sandstone canyon is in the southern Utah desert, just upstream of the Grand Canyon and downstream of Canyonlands National Park. Hetch Hetchy is in the granite-laden Sierra Nevada, amidst forests of pine and fir.
And Glen Canyon Dam can hold 26,000,000 acre-feet of water, 72 times the size of Hetch Hetchy Reservoir – although siltation over the last 55 years may have reduced its capacity a bit.
I have a personal connection to Glen Canyon – which led to my involvement in Restore Hetch Hetchy.
In the mid 1990’s I was asked to look at the Bureau of Reclamation’s CRSSEZ Model (Colorado River Storage Simulation), to understand the nature of Colorado River water being delivered to the Imperial Valley and urban southern California. I thought I would see what happened if Glen Canyon Dam were removed in CRSSEZ, and its water allowed to flow downstream into Lake Mead.
At first, I thought the simulation modeling did not work because the model results were barely different. But looking harder, it made sense. The river’s average flow was only 14,000,000 acre-feet per year. Lake Mead itself could hold twice that volume and there are other upstream dams as well. At some point, additional storage just leads to more evaporation and losses without any help for water supply reliability.
I told a few folks, including a Sierra Club rep in Arizona. Then, in 1997, I got a call, asking if David Brower and Adam Werbach (past and sitting Sierra Club Presidents) could use the results in an upcoming hearing at the U.S. Senate. I said yes, but nothing substantive happened after the hearing. Two years later, Brower suggested to Restore Hetch Hetchy founder Ron Good that he invite me to join his new organization.
At Restore Hetch Hetchy, we are committed to helping San Francisco replace the modest (but important) increment of supply that Hetch Hetchy Reservoir provides. As our recent newsletter explains, we think groundwater banking, expanding Calaveras Reservoir and recycling are the best options.
Hetch Hetchy Valley in Yosemite National park can be restored without anyone losing a drop of water supply.