The Need for Regional Stormwater Management in Southern New Mexico
Across Doña Ana and Sierra counties there are 2,400 square miles of watershed stretching from the Black Range northwest of the Caballo Dam, south to the NM-TX state line. For 800 square miles, or one-third of the area, there is no existing infrastructure to manage stormwater. This results in severe erosion, flooding, and large quantities of sediment and debris being dumped on residences, farm fields, highways, and streets during severe weather. The existing dams, constructed in the 1960's to protect farmland, have now exceeded their engineered lifetime. In addition, these dams are now protecting urban and residential areas which they were never designed to protect. Currently there is very little funding available to implement the necessary dam upgrades needed to protect residential areas. Stormwater management is typically planned, funded, and implemented independently by a variety of public agencies in towns, cities, and districts spread throughout the region. Recognizing that stormwater does not respect political boundaries, it has become apparent that the needs of the region would best be served by a regional watershed management approach.
Regional Watershed and Stormwater Management
Several local agencies that manage stormwater as part of their responsibilities have joined the South Central New Mexico Stormwater Management Coalition. The first step was the development of a memorandum of understanding between agencies with the foresight to realize that their efforts to manage stormwater would be enhanced through sharing of information and ideas, coordinated planning, consolidation of funding requests, and sharing of staff resources. Bringing the various authorities together under the current joint powers agreement (JPA) allows for greater planning and development of stormwater projects and flood control within the region, as well as recognition by the state of New Mexico. According to the JPA, the Coalition will share staff time, resources, data, and documentation, and work to improve the effectiveness of stormwater management. The Coalition is authorized to apply for, receive, and utilize grants, loans, bonds, or other financial aid from any source approved by the Coalition board of directors. The Coalition will not use mil levy funding collected by any of the participating agencies. The JPA is scheduled to be replaced by new bylaws after the bylaws are approved by the Coalition members.
Some of the specific infrastructure needs identified are:
Street-water/Storm drains needs include:
- Prevent water from entering the Rio Grande during storms to maintain river channel flood capacity
- Build regulating reservoirs to store water runoff and release the water when it can be put to beneficial use
- Use combinations of large and small reservoirs where practical
- Strategically placed pumping stations
- Large precast culverts to safely discharge floodwaters
- More lined drainage channels
- Water filtration systems to remove contaminants
Arroyo runoff infrastructure considerations:
- Build rechange systems to store suitable runoff water underground
- Branch Aquifer Recharge Systems (BARS)
- Runoff and Zone collectors for surface runoff
- Hill slope collectors and transmission lines
- Arroyo use for recreational and environmental opportunities
Infrastructure maintenance considerations:
- Upgrade and maintain existing dams and levees
- Maintain problem arroyos
- Upgrade road crossings at arroyos
- Construct bridges at restricted arroyos
- Sediment management and disposal
The next meeting is on Thursday, February 20th, 2020 at 1:30 PM. Click Here for the agenda.
Future meetings are tentatively scheduled for the following dates and locations:
- February 20th, 2020 - Dona Ana County Government Complex: Room 1-113, 845 N Motel Blvd, Las Cruces, NM 88007: NMWDOC update, NRCS Rincon Arroyo Watershed Tour review, NMED Grant Proposal, Roundtable discussions and public input.
For access to official minutes, please contact the Chairperson.
Coalition members have recently partnered on a dam rehabilitation project at Cothern Dam west of Las Cruces, New Mexico. Future erosion control projects are being investigated for the Cothern Dam watershed and the neighboring Butler Dam watershed, along with a larger sediment entrapment project near the junction of the Rincon Arroyo and the Rio Grande near Rincon, New Mexico.
The bylaws are currently being reviewed by coalition members and will be posted as soon as they are approved. An un-official copy of the current Joint Powers Agreement can be found Here. For access to the official signed version, please contact the Chairperson.