The National Park Service will conduct tamarisk control downstream from Hoover Dam in two canyons on the Nevada side of Black Canyon February 6-12, 2007. The canyon locations are:
1) Bighorn Canyon near river mile 59; and 2) An unnamed canyon designated as "Black Canyon Spring" between river mile 61 and 62.
"Visitor enjoyment and ease of access to popular hiking canyons will be enhanced by this project. It will take only one day per year for two people to keep these canyons tamarisk free after this initial removal and treatment process is completed," said Superintendent Bill Dickinson.
Tamarisk was introduced to the United States in the 19th century as an erosion control agent and ornamental plant,the highly invasive tamarisk rapidly spread and caused major changed to natural environments. The tamarisk is notorious for consuming large amounts of water (up to 150 gallons a day), crowding out native vegetation, displacing wildlife, and increasing the risk of fire danger. The tamarisk to be removed have completely blocked the access to the two canyons restricting hiker accessibility. Tamarisk may also degrade rare leopard frog habitat found in the canyons.
The timing of the project will take advantage of flooding that occurred in the canyons mid-October 2006. Then flash flooding cleared much of the tamarisk out of the main channels. The conditions now exist for crews to control the remaining tamarisk in the canyon before it re-establishes and degrades the area in the future.
The crews will use chainsaws and an approved herbicide applied directly to the stump of the plants. Cut tamarisk slash will be scattered and piled on top existing flood debris in the canyon. No burning should be necessary. Some tamarisk sprouts will be sprayed with herbicide and left to die in place since cutting will not be necessary for the plant at that early stage.
Source: U.S. Department of the Interior, National Park Service
