By Eilene Lyon
August 28, 2018
Drove back past the nearly empty reservoir at Paonia State Park. Mostly there’s just a muddy meander through the accumulated silt. A few feet of water stand at the south end nearest the dam. Cattle were grazing on the now-exposed terraced sides. As our mountains and rivers out west dry up, I expect many dams and reservoirs will become anachronisms.
August 31, 2018
The Blue Mesa Reservoir was even more stunningly void of water than Paonia’s. The basin is looking like a verdant pasture that will soon revert to its former sandy, desert-canyon self. There is a stark horizontal line between the high water mark with its row of native trees and shrubs, and the tiers of the basin, like the ridges on a clam shell. The dam seems perfectly pointless. A few houseboats cruised the lower end of the vanishing puddle. Row-crops of RVs hovered around the edges to watch the evaporation of the reason for recreating.
The Colorado River watershed is the seventh largest on the North American continent, draining 246,000 square miles (640,000 km2).1 In the mid-19th century, the river and its tributaries were still largely a mystery to Americans, part of the “Great American Desert,” i.e. everything west of the 100th meridian.
In 1869, Maj. John Wesley Powell led his famous exploration down the Colorado, starting from Green River, Wyoming. That terrifying trip and his other explorations of the west were reported to Congress.
“At the beginning, Powell reconfirmed his view, which he had already submitted to an unbelieving Congress, that two-fifths of the United States has a climate that generally cannot support farming without irrigation…‘When all the waters running in the streams found in this region are conducted on the land,’ Powell said, ‘there will be but a small portion of the country redeemed, varying in the different territories perhaps from one to three percent’ (emphasis added).” – Marc Reisner Cadillac Desert
In the 20th century, our government began extraordinary water reclamation efforts in this arid region. On the Colorado, the major impoundments are Lake Powell (Powell rolls over in his grave at the mention of this name-sake abomination) and Lake Mead.
Currently, Lake Powell is at less than 47% of its capacity, having dropped more than 35 feet since last year. Year-to-date inflows are just over 50% of the average for this time of year. Irrigation deliveries for the year barely exceed the minimum requirement.2 Are we seeing a trend?
In 2013, the seven states in the Colorado River Compact were irrigating nearly 3% of their land area for agriculture, close to Powell’s estimated maximum.3 This figure does not reflect other irrigation uses (such as golf courses and lawns). Is this sustainable in a drought? And given our changing climate, is the current drought reflecting a “new normal?”
Large reservoirs are not only outrageously expensive, they are an inefficient way to store water. The estimated evaporation rate for Lake Powell and Lake Mead combined is 1.4 trillion cubic meters per year, “and is approximately 5–6 times the annual water usage of a medium-sized city in the United States, such as Denver, Colorado.” 4
“With huge dams built for him at public expense, and irrigation canals, and the water sold for a quarter of a cent per ton – a price which guaranteed that little of the public’s investment would ever be paid back – the West’s yeoman farmer became the embodiment of the welfare state, though he was the last to recognize it…Released from a need for justification, released from logic itself, the irrigation program Powell had wanted became a monster, redoubling its efforts and increasing its wreckage, both natural and economic, as it lost sight of its goal.” – Marc Reisner Cadillac Desert
Feature image: Lake Powell’s “bathtub ring,” bleached sandstone, starkly illustrates the dramatic drop in water levels. This was taken in 2002. The ring is much, much larger today. (E. Lyon)
Other posts in this series:
- https://en.wikipedia.org/wiki/Colorado_River#Watershed ↩
- http://lakepowell.water-data.com/ ↩
- “Table 1-6. Total farm irrigated acres in the open (and percent distributions), by farm-size class by State, for all 2013 irrigated farms.”USDA Economic Research Service. Summarized data for all irrigated farms. https://www.ers.usda.gov/data-products/irrigated-agriculture-in-the-united-states/ Provides irrigated acreage from which I calculated the percent (2.87%) based on total acreage for the seven Colorado River Compact states.↩
- https://journals.ametsoc.org/doi/full/10.1175/BAMS-D-15-00224.1# ↩