By Dr. Robert Thorson
Our lives are sprinkled with new years. Most popular is the calendar year. Most exciting is the school year. Most regular is the astronomical year. Most political is the fiscal year. Most invisible is the water year, which begins and ends on Oct. 1. This is the arbitrary date marking the time when stream flows are reaching their annual nadir over much of the U.S.
Now that climate change is part of the cultural zeitgeist, I suggest we celebrate a New Year’s Eve for water, watching the ball drop during the final seconds of Sept. 30.
The tiny Fenton River in Storrs became famous in late September 2005 when UConn pumped it dry. One consequence of this error was the installation of a U.S. Geological Survey gauging station upstream from the university’s wells. This year, according to the gauge, the stream paid no attention to the new water year on Oct. 1. Rather, the discharge kept declining, dropping to a near-record low of 2.6 cubic feet per second on Oct. 11. After that it rose slightly from an evening rain, but then headed back down.
This decline is part of a statewide trend, according to the National Drought Mitigation Center, which reports moderate drought or abnormally dry conditions over most of the state. Though cooler temperatures help keep our lawns green, local ponds and streams are declining.
A fortunate consequence of the 2005 Fenton error was the launch of an excellent drought management plan at UConn. On Sept. 13, they announced a Stage III Drought Advisory, forcing mandatory water conservation, about which most of my students had no clue.
Thankfully, Connecticut’s moderate drought is just that: a minor problem, compared to what it could be, based on the categories used by the National Drought Monitor. These categories ratchet up from abnormally dry to moderate, severe, extreme and exceptional droughts.
California is in an exceptional drought. It’s been so sunny there that the average temperature has been 6 to 10 degrees above normal. In California’s great central valley, the Sacramento Water Supply Index has reached near-record low conditions. This is the worst drought since 1977 and the fourth-worst since 1906, when record keeping began. Yet in spite of ultra-dry conditions, private agricultural corporations are making a profit and the food production keeps going. Why? Water regulators are allowing the pumping of groundwater at alarming and unsustainable rates.
Earlier this month, scientists at NASA released three images showing the progressive depletion of groundwater reservoirs since June 2002. The images come from the agency’s Gravity Recovery and Climate Experiment, called GRACE, in which orbiting satellites take precise measurements of the strength of Earth’s gravity field. When an aquifer loses weight, it’s because there’s less mass, which indicates a deficit of groundwater.
The GRACE results are beyond shocking. Maximum losses occur in the Sacramento and San Joaquin River basins. There, water sucked up to support irrigation is being lost to evaporation. During the last three years alone, more than 4 trillion gallons were withdrawn from those basins to keep the price of our lettuce, tomatoes, fruit and grapes low enough so we can afford them.
To put that water loss into perspective, 4 trillion gallons exceeds the annual total used by California’s 38 million residents. At that rate of groundwater consumption, UConn could pump the Fenton aquifer at its maximum allowable rate (844,300 gallons per day) for 13,000 years. Even more staggering, that volume of water would support the normal (median) flow of the Fenton River for 18,000 years, the entire duration of our present interglacial period.
In 1974, I moved to California for a job. Only when living in the Bay Area did I realize how much my spirit needed the lushness of a deciduous spring, the palette of fall foliage and the freshness of coldwater brooks. So I moved away. Ever since then, I’ve lived in places where the water year ends with the streams still flowing.
Connecticut is one such place, which is why I celebrate a New Year’s Day on Oct. 1