Where’s the water coming from? (Part 2)
Aweek ago in this space, we established that Santa Fe’s water system is delivering 5,000 fewer acre-feet of water than it did 20 years ago, which theoretically equals 30,000 new homes that could be built (at six homes per acre-foot) before we reached 1999 deliveries of 14,000 acre-feet.
At the build rate of the past decade, that’s nearly a hundred years of housing absorption.
On the other hand, the build rate of the past decade did not match our population growth, which is why we are in a housing crisis. That means we need to build about 1,000 new dwelling units a year for a decade just to get back to the housing balance we had in 2007.
Savvy Santa Feans will note that paper water rights are one thing and delivered wet water is another. Indeed, the city has paper water rights over 23,000 acre-feet, which would seem to be a healthy cushion between theoretical and actual. The concern is that almost every drop of that wet water is dependent upon what falls from the sky in the form of snow. Snow is good, especially when it melts slowly and replenishes aquifers.
We had good snow this winter. The problem is how fast it’s going away.
The Southwest has seen persistent drought conditions since the 1990s. The dark brown blob on the color-coded U.S. Drought Monitor map shifts around the Southwest, reflecting a pattern of hotter, drier weather.
The consequence of hotter and drier weather is that snow evaporates before it melts. Less snow melting to water, because it evaporates to air, means less river flow and less aquifer recharge, which is everything we depend upon.
The interesting phenomenon is that total annual precipitation has not changed appreciably in the last 20 years — indeed, the last 60. So what does that mean for housing? It means that if we can capture and reuse what hits our roofs, we will need less of what comes from the rivers and our underground aquifers.
Buried cisterns, pumps, filtration and ultraviolet treatment are to net-zero water what photovoltaic solar panels, inverters and dual metering are to net-zero energy. It’s not rocket science.
Santa Fe is no stranger to buried tanks capturing rainwater from roofs. It’s code in Santa Fe County for homes over 2,500 square feet and has been the rule for the Community College District for well over a decade. Our mistake is thinking those captured gallons should be used to bloom the desert. Wrong. They should first go back into the house to flush toilets, shower our bodies and wash our clothes. Then, and only then, should the water go outside for our flora in the form of greywater from showers and laundry.
We know how to do this, it’s a matter of paying for it.
For existing homes, it’s ridiculously expensive — it’s still expensive for new homes doing it during site infrastructure, but less so by a huge factor. Can we double the homes we can get out of an acre-foot of water and therefore go 100 to 200 years before we’re back to 14,000 acre feet per year? Yes, we can.
To learn more about this, check out the Next Generation Water Summit at the Santa Fe Community Convention Center, June 12-14.