By Doug Simon
Next month, work should be under way to create a new wetlands area in the Corrales Bosque Preserve. A collaboration involving The Nature Conservancy, the Southern Sandoval County Arroyo Flood Control Authority (SSCAFCA) and the Village of Corrales would use stormwater flowing through the Harvey Jones Flood Control Channel and effluent from a Rio Rancho sewage treatment plant to irrigate about 10 acres adjacent to the river.
SSCAFCA advertised a request for bids for project construction in early September with a target of breaking ground by mid-October. Sarah Hurteau of The Nature Conservancy provided details about converting the stormwater outfall, between the end of the channel and the Rio Grande, using a “green stormwater infrastructure” approach in collaboration with Middle Rio Grande Conservancy District (MRGCD), SSCAFCA, the City of Rio Rancho, and the Village of Corrales. (See Corrales Comment Vol.XXXX No.2 March 6, 2021 “Stormwater, Treated Sewage Would Be Used for Bosque.”)
Additional funding for the project will be provided by a private developer as mitigation for another project elsewhere in the watershed. The Jones Channel has functioned as a storm drain carrying rain from Rio Rancho and Corrales into the floodplain of the river since the early 1990s. Deposited sediments over those years will be re-contoured and new earthen channels will be opened. Removal of accumulated sediment will allow bosque vegetation to connect to groundwater resources helping to sustain cottonwood trees and other plants throughout the year.
Stormwater from the Montoyas Arroyo and the Lomitas Negras Arroyo watersheds will be slowed and diverted through the proposed wetlands before emptying into the river. But an even more consistent and reliable supply of irrigation water will come from Rio Rancho’s sewage treatment plant at the edge of the Montoyas Arroyo and Highway 528. That effluent would provide a perennial 4-5 million gallons a day.
The sewage treatment plant has operated with a discharge permit to send effluent to the river through a pipeline that runs along the channel. When the plant is operating correctly, those millions of gallons of wastewater will be cleaner than stormwater coming down the channel in the Montoyas Arroyo. Hurteau said the stormwater diversion in the wetlands area uses the power of nature to filter and mitigate pollution as the last of a series of stormwater quality improvement sites, expanding the effectiveness of features already in place upstream. Water quality features upstream will capture floating trash and sediment for later removal. The new wetland area will allow water to slow down, spread out across the river floodplain, and sink in using natural channels, with care being taken to maintain flood protection to homes nearby, she said.
Those constructed features in the Montoyas and Lomitas Negras Arroyos will capture floating trash, and slow-moving water will allow plants and soils to act on pollutants such as automotive chemical residue along roadways. Those would be broken down through bioremediation, so pollutants from roadways are removed before they end up in the river.
This wetland also is designed to reduce bank erosion along the river. Many months of planning have gone into ensuring the design resolves existing flow issues, preventing mosquitos, and maintaining flood control capability. Hurteau said more than 5,000 postcards were sent out seeking public input and hearings were held in February and March. The team met with relevant agencies and environmental groups to review the conceptual design.
The Jones Channel in the Montoyas Arroyo and the Dulcelina Curtis Channel in the Lomitas Negras Arroyo are named for the pioneering work those two Corraleños did to control damaging stormwater in a wide territory west of Corrales. They were early members of the Corrales Watershed Board, which was subsumed by SSCAFCA when it was established by the N.M. Legislature in 1990. (See Corrales Comment Vol. XXV, No.13, August 19 & October 21, 2006 “Corrales Battles Historic Flooding, Threat at Jones Channel.”)
Back in March, the Corrales Bicycle, Pedestrian Advisory Commission recommended that the wetlands plan include a trail connecting bosque areas north and south of the Jones Channel outfall. “Our commission recommends that potential pedestrian use in the area be considered in the design,” Commission Chairperson Susan Zimmerman wrote to Village Administrator Ron Curry. “We are concerned that walkers and possibly bicyclists will make their own unofficial trails in the area if they are not designated. Simple, meandering dirt pathways are what we envision.
“We understand that the conservancy has assumed pedestrians would use the existing connection with the acequia trail from the west end of the area. We are concerned that folks would want to get closer to the river, and that this could create a potential problem if not considered in the overall plan.”