How messed up is the Rio Grande? It's one of the few rivers that has to be irrigated. Down south there is a ditch that was dug next to the river to more efficiently get the water down to Elephant Butte Reservoir. It was a great idea at the time except that it caused the river to frequently go dry. Over time the river channel became higher than the ditch. Water always flows towards the lowest point so water flows from the river into the ditch via groundwater. This was not really a problem until the Fish & Wildlife Service (F&W) declared the silvery minnow an endangered species about 10 years ago, and the entire reach of river was designated as "critical habitat." We now have a whole series of rules which we have to abide by to protect the fish.
Down in the lower reach we have pumps set up to pump the water from the ditch back into the river. If the river starts to dry before June 15, we turn on the pumps. If the river starts to dry after that date, we turn on the pumps only to keep the drying at a slow enough pace for F&W to rescue any minnows they can find. The pace that has been determined is 8 miles a day.
Yesterday I decided to turn off a pump that was propping up a good chunk of river. F&W hadn't been doing any rescue for days and the river had been holding steady. When I said we should shut off the pump, F&W complained since things were nice and steady. I reminded them that the purpose of the pumps was not to keep the river flowing (at this time of year) but only to keep the pace of drying at a manageable rate. The irrigation district supported my decision. The State of New Mexico supported my decision. And so the pump was shut off. This morning I get the news that 16 miles of river went dry overnight. Ooops! No one had any idea that that one pump that was running was supporting that much river. I think we were all shocked at the news. The pump was quickly turned back on and F&W went out to rescue fish.
Hopefully we won't get spanked too hard for this. Like I said, I will take full responsibility for the decision to shut off the pump. It seemed the prudent hydrologic thing to do. The argument for keeping the pump on is simply that it only costs diesel fuel to keep it running. There is no risk in keeping it on while the risk of shutting it off is great. I probably should have turned on another pump further downstream, but hindsight is 20/20.
This also illustrates why I enjoy my job. I have been working with the Rio Grande for 7 years now and it keeps throwing surprises at me. I'm not foolish enough to say that I understand how the system works implicitly. The system constantly changes and new things are always cropping up. This also makes things difficult for me since folks look to me as the expert. They don't want to see me shrug my shoulders and say, "I dunno!" I always let them know, however, that predicting river flows is about as easy as predicting the weather. And we all know how good the weatherman gets things right.
Oh, and now it's raining outside. *headdesk*