The people in the town of Raton, N.M., know that a wildfire’s effects don’t end when the last smoldering ember is extinguished.
The “Track Fire” originated June 12 on the northern outskirts of Raton and quickly got out of control. It eventually burned almost 27,800 acres, thousands of trees and much of the ground-cover vegetation of the watershed around Lake Maloya in Sugarite Canyon, which straddles the New Mexico-Colorado border. Without the trees and ground-cover vegetation which slow water flow, monsoons threatened the lake. And, the monsoons come in late summer, the wettest months of the year there. With no intervention, officials knew extensive erosion from high water flows would carry ash, dirt and debris into the streams feeding Lake Maloya, fouling the water and making it turbid.
Turbidity, a liquid’s cloudiness or haziness, is measured in Nephelometric Turbidity Units or NTU. The NTU level constitutes a key test of water quality. Water with lower NTUs is easier to treat; the town’s water treatment plant can’t treat water higher than 15 NTUs.
The majority of the town’s potable water comes from Lake Maloya, as Raton does not have viable ground water sources. Furthermore, while the Cimarron pipeline transports water from a secondary source at Eagle Nest Lake, N.M., it’s not reliable in winter.
Dan Campbell, general manager of Raton Water Works, pointed out the town’s biggest priority: preventing as much sediment as possible from getting washed into the lake.
In an attempt to reduce the risk to the town’s water supply, town officials called the District. Under Section 404 of the Clean Water Act, the Corps has to approve actions that affect streams and wetlands and many of the options the town considered would require Corps’ approval.
Raton applied for an Emergency Individual Permit. When approved, the town could start work on various risk reduction actions before the monsoons arrived. The normal process of getting an individual permit takes 120 days. Raton wanted (and needed) to begin work immediately.
On June 24, the District’s Chief of Regulatory Division Allen Steinle and regulatory project manager Deanna Cummings traveled to Raton to view the damage to the watershed and discuss with town officials what they were considering as options to protect their water. Over the next few days Cummings coordinated with the town of Raton and other agencies to get the necessary information for the permit application. Cummings had emergency consultations with both New Mexico’s and Colorado’s Fish and Wildlife Departments. She got water quality certifications from both the New Mexico Environmental Department and the Colorado Department of Public Health to show that the proposed project wouldn’t violate state water quality standards. Then the approval package went to Division headquarters in San Francisco for the Division Commander’s approval. The seriousness and tight timeline from the monsoon threat enabled Cummings to use emergency permitting procedures to expedite the process and get the permit approved in about a week. However, the town still has to undergo a compliance follow-up, and Cummings must conduct an “after-the-fact” evaluation.
The permit approves the construction of sedimentation retention basins within existing ephemeral streams or adjacent to stream wetlands in three of Lake Maloya’s major tributaries — three basins in New Mexico and one in Colorado. According to Cummings, these basins are an “effort to try and retain sediment before it gets into the lake.”
The town’s plan: as the basins fill with sediment, town workers will restore them and build more basins upstream, replacing the first basins. The permit will be modified to add new basins as needed over the next three to five years, Cummings said.
When constructing a basin, the first foot of soil will be set aside. It contains a seed bank, and this will be used to help restore the basin after it fills with sediment.
Officials also plan to use Lake Dorothey, located upstream from Lake Maloya, as a sediment retention basin. According to Cummings, it is a “dead pool” with the water outlet higher than the water level, so the only way to drain the lake is pumping the water out.
The basins could fill up with sediment and debris after just a few storms, because the fire damage alters the peak flows. Based on data from recent fires in two nearby watersheds, the high flows can be estimated. The first year is approximately 10 times the normal peak; however, the second year it increases to approximately 200 times normal. Cummings added that it “then slowly goes down as vegetation increases.”
The town is also installing sediment curtains in Lake Maloya where three tributaries enter the lake. The town doesn’t require Corps’ approval for this installation. Similar to a wall, the curtain is anchored at the bottom and has floats on top. Typically these are used in lake dredging projects, but the town hopes they will be another barrier to keep sediment and debris out of the water.