Channels have been excavated in the Corrales Bosque Preserve between the outfall of the Harvey Jones Flood Control Channel and the Rio Grande to distribute stormwater to a proposed ten-acre wetlands. Major earthwork has been underway since early November to use not only stormwater from the vast Montoyas Arroyo watershed but also treated effluent from a Rio Rancho sewage plant on the edge of the arroyo near Highway 528.
The project is a collaboration among the Village of Corrales, the Southern Sandoval County Arroyo Flood Control Authority (SSCAFCA), the Middle Rio Grande Conservancy District, the City of Rio Rancho and the environmental goup The Nature Conservancy. (See Corrales Comment Vol.XXXX No.2 March 6, 2021 “Stormwater, Treated Sewage Would Be Used for Bosque.”)
SSCAFCA advertised a request for bids for project construction in early September when it had 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 river, using a “green stormwater infrastructure” approach.
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. That effluent would provide a perennial four to five 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 flood control 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.
A grader, two front-end loaders and dump trucks worked the riverbank area between the Jones channel and the river in mid-November to create two paths for stormwater to follow on its way to the river. During major storm events when large quantities of water are pouring through the arroyo, the water would be directed more or less immediately to the river, while during lesser storms, the water would go to a more meandering, distributive channel.
Once the earthwork is completed, trees and other vegetation will be planted, probably in early spring.
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.
The wetland 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 2021. 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 of this year, 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.”