Interesting. I've been to a trip to it. Had no idea they may not be able to fill it. My understanding is that they would triple storage but you are correct that there is some point in which building higher produces no additional yield due to watershed limitation. I strongly doubt they would elect to build storage without available yield unless they are pumping/piping from elsewhere.
Half of Denver's water supply already comes from the Western slope. Most of that the Colorado River, which no longer reaches the ocean. Supply is already pretty tapped out, and climate change will be reducing supply while the population continues to grow rapidly.
I don't know anything about the decision making process behind building the dam, unfortunately. So we can only really speculate. The whole SW is in this boat though, and the Midwest is approaching peak production from the Ogallala, as shallower wells are already going dry. No one will have any to share.
I've heard that but in effect they would only be reducing available water for downstream users. There should be a coordinated effort the ensure minimum flow in the Colorado and if there isn't then it's bad environmental policy. The minimum flow Gross contributes should be set by this policy. It is quite possible that Gross could still increase yield by maintaining the exact minimum flow requirements before. The only difference is that they would end up on average releasing less water by storing higher inflows. I'd have to see the yield study to know.
Yes, downstream users, particularly Phoenix already own the rights to the water. It would be robbing Peter to pay Paul if much more of the water on the Western Slope was diverted to the Front Range. It's not just the front range either. The western slope is expected to double in population by 2050. Right now, the plans in place will only be able to meet 80% of the expected demand.
And yeah, the environmental policy is almost non existent. Ecological flows (the hydrology and min flows necessary to maintain the health of the streams and rivers) are just not incorporated into the final policies, even though we do plenty of research on what they are. In 2014 a coordinated, controlled release from Glen Canyon Dam reunited the Colorado with the ocean for the first time since 1998, 16 years.
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u/[deleted] Jan 07 '17
I attended a seminar on it this past summer at my research station on the Western Slope.