River Beat: Drop 2 and the hunt for increasingly marginal water

Shaun McKinnon this morning has the good news that the new Drop 2 reservoir out along the All-American Canal in far southeast California doesn’t leak. Well, actually, the “doesn’t leak” part is not a big surprise, but provides a nice news peg for an update on why this tiny project matters:

The $172 million project is an attempt to seal decades-old leaks in the Colorado River’s water-delivery system by capturing the dribbles lost downstream to Mexico when farmers in Arizona and California don’t take water they ordered, usually because rain filled the need.

That water can now be shunted into the reservoir and held until the farmers ask for it again. The U.S. Bureau of Reclamation estimates the project could save as much as 70,000 acre-feet of water a year, water that can remain in Lake Mead as a hedge against drought.

Drop 2 Reservoir Inlet

Drop 2 Reservoir Inlet, courtesy USBR

I say “tiny” because 70,000 af is on the order of one half of one percent of the Colorado River’s flow. That illustrates one of two key points illustrated by the Drop 2 project – that the agencies that manage and use the Colorado’s water are operating right now at the tiniest of margins as they squeeze the river dry.

The second key point is that, in the desert, there’s never really any water “wasted”. To the water consuming community along the Lower Colorado River, water order from Hoover Dam but then left unused because it rained was “wasted.” But as Shaun points out, it ended up somewhere, and it did something:

Conservation groups say the water that escaped the Colorado’s system of canals was never wasted because it helped sustain the river’s few remaining riparian areas on the river’s delta in Mexico. Those areas still need a source of water to survive, the groups say.