A City, If You Can Keep It: The water limitation

A Winters Express op-ed column

Water will be the resource that ultimately limits growth in Winters. We have a hard limit on how many new homes that can be built without depleting our water resources. Land can be converted and repurposed, bought and sold. But we can’t buy a magic wand from Diagon Alley, shout Aguamenti with a flick of our wrist and create more water.

We need to know the maximum number of homes our local water resources can support. Is it an additional 200? 1,000? 8,000 new homes? Frankly, this should be determined before we continue to spend time and money planning new developments. Measure the limiting factor before starting other movements. On June 1, the Yolo County Flood Control & Water Conservation District published a report that included slides on “Areas of Special Concern in (the) Yolo Subbasin: City of Winters and Hungry Hollow Area.” The punchline is there is a potential trend emerging in declining groundwater levels around Winters. The average water use per home as of 2016 is 85 gallons per day. The more homes we build, the more water we pull from the wells around town. Emerging trend or not, there is a number of total homes that Winters can support before we are using water faster than the aquifer is refilling. Each year is different, as rainfall fluctuates, but the focus should be on total city and surrounding agricultural water use vs. drought year water levels. Councilmember Jesse Loren — who as a result of putting her hands into everything, garners disproportionate mentions in this column — is our city representative for the Yolo Subbasin Groundwater Agency. The meeting in which the information on declining groundwater elevation was reported there occurred on June 21. What I don’t recall is any report on this during council comment period to date. This is actually not surprising since the council comment period, or as I like to call it, the “How I earned my $180 in the past two weeks” report, is often a formality that is waste of time with little substantive information beyond a roll call of who went to what meetings. I presume important issues like ground water elevation trends are discussed in the meetings mentioned, but the only reports we hear are “I attended meeting X. I had coffee with citizen Y. I met with the city manager to discuss the agenda for this meeting.” The “so what?” is often omitted. The water issue is really not complicated, aside from collecting the data, a task which is already done on large scale statewide. Some predictive analysis and projections will need to be run as well, but for simplicity’s sake we can look at historical levels since the groundwater model for the county is still in development. From there it is just math: Current City Water Use + Average Agricultural Use + X Number of New Homes * 85 gallons per day (adjusted for whatever time period we are measuring, month, quarter or year) = Total City water requirements. Groundwater recharge from the creek and rain – City water use = Y feet change in groundwater elevation/time period. Compare that information to drought-year groundwater levels and we should be able to estimate how many additional homes can be built before we have a problem. That was a highly simplified breakdown, but I think I covered all the elements. However, as the First Sergeant I worked with at the end of my army career used to say, “Simplicity of thought does not equal simplicity of action.” The new Farmstead Subdivision plans for 200 new homes and 84 apartments, that is roughly 24,000 gallons of additional water per day that will be required. Heartland and Stones Throw have about 800 homes planned, requiring another 68,000 gallons per day. Combined those three developments need 33.5 million gallons a year, or enough water to cover one acre in 103 feet of water. That’s about 40 percent more water than the homes in town currently require. Taking a very simplified approach to the question, given the environmental conditions of the last five years, residential water use has a depth to groundwater correlation coefficient of 0.59. Average city well depth to water has increased 10–15 feet since 2016 when the new home construction began. So, each new home may result in a half inch increase in depth to water. Therefore, as a rough estimate using available data, our aquifer can support between 2,500 and 4,400 more homes depending on if we are in a drought — 1,000 of which are in various stages of planning or construction.