LAS CRUCES, N.M., -- Instead of the traditional red ribbon cutting, officials from the Corps and the city of Las Cruces tossed seed balls packed with a mixture of wildflower seeds that will sprout with the next rain in a grand-opening ceremony Sept. 5, 2014.
The ceremony officially opened a $1.6 million environmental restoration project near the Las Cruces Dam consisting of a wetland, meadow, arroyo riparian habitat, and playa habitat. A playa is a shallow depression or basin that is occasionally or seasonally covered with water.
“It’s truly my honor and privilege to be here today with our team of District employees and partners that have done such a great job on this project,” said District Commander Lt. Col. Patrick Dagon.
The Las Cruces Dam was constructed by the Corps of Engineers in partnership with the city in the mid-1970s. Its purpose is to protect the city from flood waters and sediment moving down the Las Cruces and Alameda arroyos after heavy rainfall on the foothills and slopes of the nearby Organ Mountains.
However, this protection came with a cost: by changing the flow of water down the arroyos to the Rio Grande, water no longer reaches downstream wetlands, desert shrubs, and streamside cottonwood forests. These natural habitats have been altered or lost.
The newly opened project had been in the works since at least 2005, according to the city’s Public Works Director Loretta Reyes, when the city contacted the Corps to see about funding for an environmental restoration project along the dam. In 2012, the District and the city began work to restore some of the natural habitats within the current flood pool of Las Cruces Dam.
One might question if a wetland in the desert could be sustainable. Where does a reliable source of water come from in an area where every precious drop is accounted for? Planners took this into account when designing the wetland and engineered it to local site conditions, such as porous soils, high evaporation rates and low precipitation.
The water comes from the East Mesa wastewater treatment plant and is delivered by gravity from the treatment plant through a water pipe to the wetland. While the water is clean enough for irrigation use, it is not for human consumption!
Water enters the wetland at a maximum of 10,000 gallons per day. Delivery is carefully regulated so the wetland doesn’t overflow or evaporate away. The water flow is managed by a float valve: when the wetland is full, the float reaches its highest level and an attached valve cuts off flow from the water pipe into the wetland. When water levels fall, the float falls with it, opening a valve that allows reclaimed wastewater to enter the wetland. Because the reclaimed wastewater is delivered to the wetland by gravity flow and regulated by the float system, electrical power is not needed, creating a truly “green” system.
The wetland and meadow provide beneficial habitat in the desert where water is an extremely scarce commodity. Migratory birds now have an invaluable resting area along the Central Flyway, especially as many historic wetland resting areas have been diminished.
The playa area provides habitat for many different species of wildlife, including toads, salamanders and fairy shrimp that use the intermittent water to complete their breeding cycle.
The benefits of the project aren’t limited to just wildlife and plants. Humans can access the area via a system of trails, including one that provides visitors with disabilities access to the wetland and educational area and the playa overlook. A shaded observation deck at the south end of the dam has two monoculars allowing people a way to observe birds and other wildlife.
Bird watchers are already enjoying the area as City Councillor Gill Sorg noted in his remarks about the project. “Already as many as 190 species of birds have been identified in this area,” he said, including some birds that are only found in this area.
School groups of all ages can come and learn about the local ecosystem. District Project Manager Alicia Austin Johnson describes the area as “an outdoor learning laboratory.” There is an educational kiosk that provides information about different birds and vegetation in the area. Interpretive signs placed throughout the project can spark the interest of budding scientists in learning more about their home in the Chihuahuan desert.
“We hope the public comes and visits this area, enjoys the opportunity to peek through the wildlife blinds at unique birds, or ponder the unique inhabitants of the playas at the overlook,” said Austin Johnson.