Letter: Issues with Upper Colorado water conservation program
The recent article from Aspen Journalim’s Heather Sackett on officials in the Upper Colorado River basin moving closer to a water conservation program fails to mention three extremely important factors in the use of Lake Powell and Lake Mead as reservoirs. The first is that the evaporation from these large water bodies is extremely high, and so it would be sensible to have just one deeper water body (Lake Mead), and particularly at times of drought, so that loss through evaporation is effectively halved.
The second factor that makes the current situation so alarming is that the reservoirs are both sitting on ground that is largely porous rock, so even if we get high precipitation, the levels in the reservoirs will not rise much because the water table has dropped so much due to extraction of groundwater that the leaking is much higher than when the reservoirs were first built.
Having just one reservoir would halve loss through seepage. The third factor is that all reservoirs eventually silt up and get shallower and shallower until the reservoir no longer serves its original function. Shallow reservoirs not only hold less water but will be more susceptible to evaporation as time goes by and in the not too distant future Lake Powell will cease to exist and then Lake Mead will begin to silt up and eventually also “die.”
A better way forward than just cutting water use, which is always going to be needed regardless of precipitation returning to pre drought levels, is to decommission Lake Powell and use the Glen Canyon Dam as just an excellent silt trap for Lake Mead. That will likely sacrifice the community of Page but unless Lake Powell starts to fill soon, which is unlikely for the reasons stated above, then Page is surely toast anyway.
Nicholas T. Fickling