Thursday, July 05, 2012

Gauges to warn of post-fire hazards from Whitewater-Baldy fire

The USGS has installed 6 rain and stream gauges in the upper reaches of the Gila National Forest water shed in New Mexico where the burning from the Whitewater-Baldy fire was most severe.   "Now that the fire is largely contained, attention has shifted to preparing for post-fire flooding with the onset of monsoon season. Communities downstream from burned watersheds are at risk of flash flooding and debris flows because of the loss of vegetation and the burned soil’s reduced ability to absorb water."  [Right, USGS hydrologist installs rain gauge at Hummingbird Saddle, Gila National Forest. Credit, USGS]

The Whitewater-Baldy fire is the largest in New Mexico history at nearly 300,000 acres.  It is currently about 87% contained.

Although the fire did not burn into Arizona, the drainages do extend into the eastern part of the state, raising concerns that flooding and debris flows could do damage here.   AZGS geologist Ann Youberg has been collaborating with federal, state, and county officials from both Arizona and New Mexico to assess the hazards and develop mitigation plans.  The new rain gauges will help assess the potential for flooding on the San Francisco River, and the town of Clifton in particular, in Arizona.

The USGS also announced that on Friday, July 6, they and the U.S. Forest Service will host a community workshop in Glenwood, New Mexico, to show residents how to access the data provided by the new gages and answer questions about the alert system. The workshop will be held at the Glenwood Community Center and will begin at 6:00 p.m.

The InciWeb site reports a variety of efforts are underway to mitigate flood and debris flow damage:

Stream channel widening and improvement has been completed on Whitewater and Mineral Creeks. This work was done in cooperation with work that Catron County and New Mexico Dept. of Transportation (NMDOT) has been doing in both of the creeks. Work included: channel widening, vegetation removal, improving existing dikes and levees, and creating sediment traps.

Jersey (cement roadway) barriers have been placed around the pump house and below the historic Graham Mill site at the Catwalk parking lot and along the Mineral Creek road by Cooney's Tomb.

Hazard trees along the Bursum Road are being removed by a local fire crew.

Work around the Gila River Bridge over the West Fork of the Gila River has begun. Crews will be removing vegetation within the river channel and riprap (rock erosion barriers) will be installed along the river bank to protect the bridge abutments.

Although the monsoon rains have begun, stream flooding has not been occurring, although black, ash-laden water has been flowing down Whitewater Creek, Willow Creek and in the West Fork and Middle Fork of the Gila River. The communities of Glenwood, Alma, Pleasanton, and Willow Creek are all working hard to be prepared. Sandbagging sessions have been occurring and residents have been placing sandbags around their property. Residents are urged to watch the weather closely and heed issued flood warnings.

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