Manipulating Rivers
Civilization grew up around the manipulation of rivers, so I don't want to suggest we shouldn't, but there are limits to how much manipulation is a good thing. This became a theme of my trip to the Bosque del Apache Wildlife Refuge along the Rio Grande in Central New Mexico. The refuge sits on land that was once a constantly changing braided river channel of the Rio Grande. As the river migrated back and forth finding new channels and abandoning old ones, the resulting pools of water would attract migrating waterfowl like Sandhill Cranes and Snow Geese.
Birds migrating is accepted as a good and natural phenomenon. But when a river wants to migrate back and forth within a broad floodplain, it's seen as a sign of an undisciplined Nature that needs to be brought under control. The US Bureau of Reclamation and the Middle Rio Grande Conservation District responded to that challenge by channelizing the river, building Elephant Butte Dam (completed in 1916), and constructing a 80km "low flow conveyance channel" parallel to the river to make sure water could flow into the reservoir created by the dam. Otherwise the river's water tended to form pools and some of the water would be lost to infiltration.
The modern refuge, which has been under development since the 1930s, effectively replaces some of the standing water that would have existed had the river not been channelized and bypassed. The refuge today is more farm than wildland. Fields are plowed, planted, and irrigated to attract the geese and cranes, using pumped groundwater, since the river is often dry. What looks like a natural floodplain is intensively managed to enhance the bird population, often at the expense of pesky mammals such as beavers (which are relocated) and coyotes (which have been culled in the past, but no longer).
The management policy of the refuge has been evolving towards a more natural approach, with a new conservation strategy in the works (click here for a 6MB pdf summary). But how natural can and should the management be? Hopefully the refuge plan will include a path to the otherwise out-of-sight-out-of-mind Rio Grande. I was able to drive up to the low-flow channel, but there's not even foot access to get a view of the river. In a very literal sense, we can's see the river for the trees!
Irrigating the Refuge
Sandhill Cranes and geese enjoying the Refuge
Low flow conveyance channel in the Refuge
Elephant Butte Dam and reservoir downstream from the Refuge
Birds migrating is accepted as a good and natural phenomenon. But when a river wants to migrate back and forth within a broad floodplain, it's seen as a sign of an undisciplined Nature that needs to be brought under control. The US Bureau of Reclamation and the Middle Rio Grande Conservation District responded to that challenge by channelizing the river, building Elephant Butte Dam (completed in 1916), and constructing a 80km "low flow conveyance channel" parallel to the river to make sure water could flow into the reservoir created by the dam. Otherwise the river's water tended to form pools and some of the water would be lost to infiltration.
The modern refuge, which has been under development since the 1930s, effectively replaces some of the standing water that would have existed had the river not been channelized and bypassed. The refuge today is more farm than wildland. Fields are plowed, planted, and irrigated to attract the geese and cranes, using pumped groundwater, since the river is often dry. What looks like a natural floodplain is intensively managed to enhance the bird population, often at the expense of pesky mammals such as beavers (which are relocated) and coyotes (which have been culled in the past, but no longer).
The management policy of the refuge has been evolving towards a more natural approach, with a new conservation strategy in the works (click here for a 6MB pdf summary). But how natural can and should the management be? Hopefully the refuge plan will include a path to the otherwise out-of-sight-out-of-mind Rio Grande. I was able to drive up to the low-flow channel, but there's not even foot access to get a view of the river. In a very literal sense, we can's see the river for the trees!
Irrigating the Refuge
Sandhill Cranes and geese enjoying the Refuge
Low flow conveyance channel in the Refuge
Elephant Butte Dam and reservoir downstream from the Refuge
Posted by Dave Groenfeldt at 25 Nov 2011, 1:33 PM 
Categories: Natural Resources Management, River Management
Tags: Bosque del Apache US Bureau of Reclamation Middle Rio Grande Conservation District
Categories: Natural Resources Management, River Management
Tags: Bosque del Apache US Bureau of Reclamation Middle Rio Grande Conservation District
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