Bonito Lake drained as dredging work nears

• Late 2017 still operable reopening date for the lake

After months of almost being at a stalemate, the situation at Bonito Lake in Lincoln County lurched forward this week.

The lake, which is owned by the city of Alamogordo although it lies within Lincoln County, was devastated by rivers of sediment deposited after the 2012 Little Bear Fire burned the watershed above it.

"It's all good news, we're moving ahead," Bob Johnson, contract coordinator for the Alamogordo Public Woks Department, said Thursday. "The cultural and biological studies are completed and there are no spotted owl habitats within a quarter mile, so we will not be restricted to just working six months out of the year."

The lake, which was a water supply source for the city of Alamogordo and Holloman Air Force Base, as well as a popular recreation site before Little Bear Fire, has been closed since June 2012. A main drainage line from the lake clogged in August, but was cleared, and  Johnson said the lake nearly was drained completely Thursday.

"There's at least 50 feet of sediment (on the bottom), much more than we anticipated," he said.

Justin King of King Industries, the city of Alamogordo's Federal Emergency Management Agency consultant working directly with the city's consulting engineer Bohannon Huston Inc. as onsite Bonito Lake project manager,  said, "The lake is almost entirely drained today and all the sediment from the fire is exposed, except (by the dam), nearly the entire lake bottom. That's a whole bunch of dirt."

But steps for recovery of the lake are unfolding as anticipated, he said.

"The survey flight was flown last week and I am meeting (Friday morning) with Terracon out of Las Cruces about the bathometric work," he said. "They would core to see how thick (the sediment) is, how much material and the depth at different areas. We're supposed to give them an introduction to the lake and take them to the dam site so they can familiarize themselves."

If selected, officials with the firm that has offices in Las Cruces could put together a mobilization team within the next week, King said.

"They will assess the lake and determine what can be done," Johnson said. "The weather is the only thing we can't control. Over the next 30 days, a number of different engineering teams will be carrying out assessments about things that are way above my pay grade."

During a report on the lake as part of a forest health series at Eastern New Mexico University-Ruidoso in August, Johnson told the audience that because of the amount of material that washed into the lake after the fire and the logistics of dredging, Bonito Lake probably will not reopen until late 2017.

Every time the area experiences a heavy rain, which was frequently this summer, more ash and debris rolled down from the watershed, he said.

"The South Fork has not run fully yet," he said. "That is an event waiting to happen."

When the lake was full, it held 1,500 acre feet of water, King said. One acre foot equates to 325,853 gallons of water.

The water from the lake could provide one million gallons a day for the city or 20 percent of its average daily use, Johnson said during the August report. The lake is the city's cheapest water source, because it is gravity fed and no pumping is required. It also is the least costly to treat. For those reasons, Bonito Lake remains valuable, despite the challenges ahead, he said.

King said in monitoring the watershed, he witnessed a distinct improvement in the clarity of water draining into the lake, which would mean by the end of the project in 2017, "the quality of water will be something we can maintain."

The FEMA is funding 75 percent of the project to remove the ash and sediment, but only the material caused by the fire. The city and state are splitting the remaining cost.

Previously, two studies came up with different amounts of cubic yards specifically tied to the fire. The new coring study on the exposed sediment will be essential in proving to FEMA officials the fire-caused drainage.

No changes are in the works for reopening the city's campground, as Alamogordo officials continue to consider proposals as not being cost effective.