Acequias can help fend off some climate change impacts, researchers say

Centuries-old acequia systems in New Mexico can help offset some effects of climate change, according to Dr. Connie Maxwell, a researcher at the Water and Community Collaboration Lab at New Mexico State University. 

Her presentation to legislators on Tuesday, Sept. 7, says acequias can mimic slowly melting snowpack, the biggest source of water in the state.

A chart in the presentation shows spring runoff actually beginning in February under a climate change scenario, and ending in mid-May. The same chart shows that acequias help delay the beginning of the runoff to mid-April and keep it going until mid-July.

Farmers spread water flow from acequias across the floodplain fields, where it seeps into the soil, and then is released again slowly to the river. This process also recharges groundwater, which also contributes to surface flow, Maxwell wrote.

The presentation cites research from last fall that concluded that acequia-based communities have been adversely impacted by recent regional population growth, urbanization, a changing demographic profile, economic development and cyclical drought. 

The research found that while acequias in New Mexico may produce a relatively small amount of agricultural products compared with other parts of the country, they perform important hydrologic functions like aquifer recharge and late-season groundwater return flow.

“These functions provide important hydrologic benefits to downstream municipalities and irrigated agriculture, as well as riparian areas, adding importantly to the value of acequia agriculture,” the researchers wrote. “These hydrologic functions could become even more important in the event of long-term drought.”