Why we do the work we do in New Mexico: Watch the Video
On Friday afternoon, July 11th, 2014 the Lower Embudo Valley of New Mexico received .66" of rain.
No big deal, right?
That's not the Rio Embudo in the videos. Those are dry arroyo landscapes turned to high-velocity sludge-sluices in a matter of minutes. The brief monsoon-driven rainstorm ran off three major arroyos that drain to the Rio Embudo—Arroyo la Mina, Arroyo del Pino, and Arroyo del Plumo (Cañada de Apodaca)—and many smaller ones. The first hour of the storm produced 0.39 inches of rain, the second produced 0.27 inch. In that first hour, ALI's monitoring Site 1 on the otherwise placid Rio Embudo registered a silt-laden wave of 7.26 feet surging past.
The USGS gaging station below Site 1 recorded a discharge approaching 200 cfs (cubic feet per second). To put that in context: that morning, the river had been flowing at a gentle 10 cfs. In early summer 2013, at the nadir of drought, the river routinely ran at just under 3 cfs.
The July 11th rain undermined a former gaging station, just upstream from the Acequia Junta y Cienga's presa, causing it to collapse into the Rio Embudo. Flows destroyed the presa, or intake point, for the Acequia Junta y Cienega. Flood water flowed unimpeded into the acequia, filling it with silt and sediment. A dam structure and acequia presa slightly upstream from the Vivac winery were also destroyed.
The rain event significantly altered the character of the riverbed at Site 1: the cobble bottom is no longer visible, the channel profile is uniformly flat and smooth, and the river channel's shape is more incised and has been straightened.
It rained again on the night of the 12th, again reaching 200 cfs. On the night of the 14th, flows peaked at 538 cfs, three times the volume shown in the videos.
In the context of historic drought levels in the area, the flooding brings two responses from local residents who farm the valley: Thank God for the rain, a blessing. And its equal and opposite: Help us, the rain has the potential to destroy our roads, our irrigation ditches, our crops, our bank accounts, our way of life.
Wet will be wetter; Dry will be drier.
The simplest phrasing of the impacts of climate change on the hydrologic cycle is this: wet will be wetter, dry will be drier. For the Lower Embudo Valley, as for much of the US West, this means longer and more intense drought cycles; less snowpack in the mountains and therefore less snowmelt feeding river systems and the farming traditions that depend on them; and greater impacts of seasonal water-laden clouds arriving from the Pacific.
If your water systems have always depended on the steady flow of snowmelt in a riverbed, and that flow is diminished; and if your water systems and land holdings have always been threatened by arroyo run-off, and that is increasing, what are your options? What might be the best way to minimize destructive impact and at the same time maximize the capture and storage of storm water to supplement snowmelt? Those arroyos, as the videos demonstrate, mean business. The magnitude, quality, and velocity of the flows make arroyos extremely difficult to manage beyond "get out of the way" and "rebuild afterward." Would it be possible to manage the landscape in such a way that torrential monsoon runoff is slowed? Captured? Percolated? Stored as groundwater, available for sustaining life through dry periods? Could the liability of storm runoff be converted to productive asset?
Building climate resilience in the Lower Embudo Valley requires both care and urgency. It requires retooling the shape and behavior of the landscape itself and adjusting land use and farming practices to take advantage of changing conditions. Change won't come easily, but it needs to come, by most measures, rapidly. The landscape has worked the way it has for, oh, 29 or 30 million years. The farming traditions in the valley have worked for 10,000 years, acequia culture for the last 400. (Read more on acequia traditions here and here). ALI has worked in the area for ten.
Embudo Agua Limpia: An Updated Watershed-Based Plan for the Lower Embudo Valley
Balancing the wisdoms of tradition with the need for rapid adaptation is a challenge and an opportunity for the people of the Lower Embudo Valley. ALI is privileged to be a part of the Valley's adaptation process.
Alongside farmers, community leaders, a team of citizen-scientists, Ecotone, a Santa Fe-based environmental services firm, and collaborators in multiple state and federal agencies, ALI leads the EPA-funded project, Embudo Agua Limpia: An Updated Watershed-Based Plan for the Lower Embudo Valley. The goal of the project is to identify the sources, volumes, and rates of sedimentation and siltation in the valley through two years of monitoring, mapping and analysis. With precisely quantified and geographically specific data, the people of the Lower Embudo Valley can make a strong case for funding and implementing strategic interventions in the arroyo landscape. It is just one piece of a long-term proces that integrates science with tradition, policy with practice, and design intention with natural forces.
With the Summer 2014 monsoon season occuring at the half-way point in the project, the storms provide valuable data for the planning and design process. According to Jan-Willem Jansens, approximately 2 feet of sediment aggregated at Arroyo del Pino, creating a delta of cobble and gravel that dammed river flow. When the flow broke through, it created a new meander and widened the river. Downstream, the river bed choked with sediment nearly as high as the banks, posing further flood risks along the river at the next rain.
At Arroyo la Mina, according to Jansens, "Dump trucks removed dirt from the Arroyo la Mina culvert area every 3 minutes all day. If they transported 12 tons every 3 minutes for 8 hours, they may have taken out as much as 2,000 tons of dirt from the culverts of Arroyo la Mina in one day. Sediment is deposited on BLM land north of Apodaca."
"The Arroyo la Mina has been a major source of sediment in the last four days," Jansens continued, "but I have a sense that the other arroyos in the village play a significant role as well, and cumulatively a larger one than the Mina just by itself. I doubt that a dam (in the Mina) would help much. I estimate that the 2,000 tons (or more) of dirt removed today from the Mina are probably only a small part of the amount of sediment that flowed through that arroyo this weekend. It's probably less than 10% of the total amount of sediment that entered the Rio Embudo. Our modeling will have to substantiate these guesses and pinpoint where the sediment comes from and in what kinds of pulses it is transported down to the Rio Embudo."
The time is now.
ALI's research lead, Peter Arnold, says, "The issue of erosion and what to do about it is now at a critical phase. There will be no fast, cheap solution that is pain free for all, but finding possible solutions to curbing the impact of the arroyos in the longterm IS one of the outcomes of the EPA watershed-based planning work that we are all undertaking together. We will need the cooperation and trust from all the players: BLM, USFS, State Land Office, Rio Arriba County, Lower Embudo Valley Acequias and the Community-at-large, in addressing this."
Jan-Willem Jansens echoed that: "What happened this weekend is a good justification for why we are doing the planning project. We will need argumentation that mobilizes millions of dollars to address these issues. I agree with Peter's observation that there will be no fast and cheap solution, and it will take a lot of collaboration indeed."
When the study concludes in mid-2015, the people of the Lower Embudo Valley will have the data they need to make a compelling case for effective strategies, well adapted to both the culture of the valley and the changing behaviors of the hydrologic cycle. Long-time Embudo Valley resident, farmer, and community leader Estevan Arellano looks ahead to the design and implementation phase: "We need the help of all the thinkers out there (landscape architects, historians, land use planners, politicians)…. Let's see if we can all put our heads together to come up with a workable solution. It would be great if we could save the water that is causing so much damage to be used during times of drought. Let's here your comments. Put your thinking caps on and offer solutions to a real problem."
The Embudo Valley is an inspiring, real-time case study in careful, rapid adaptation, a process all of us can learn from and apply in other locations, urban and rural. We invite you to join the ongoing research, planning, and design process. The future holds ample opportunities for residents, farmers, students, summer interns, research fellows, educators and design professionals. Interested in engaging the process? Drop us a line.