Parts of Wisconsin officially in ‘moderate drought’: cooler temperatures soon, but rain unlikely to relieve burn restrictions
Post by Christie Taylor on 7/6/2012 1:20pm
With .31 inches of rain observed in June (a normal June sees more like 4), and none so far in July, Dane County is dry right now. Daily forecasts of “isolated thunderstorms” and 20 to 30 percent chances of precipitation have, so far, yielded no thunderstorms and almost no precipitation since June 21. And a few traces of rain--less than a hundredth of an inch each--on Monday and Tuesday weren’t enough to stop the county from falling officially in the “moderate drought” category, the U.S. Drought Monitor indicated in its weekly update Thursday.
In June, Wisconsin communities broke 34 maximum temperature records, and tied 32 more, including six in Dane County. In addition, the state broke 76 minimum temperature records--setting new records for hot nights--and tied 21, with 11 in Dane County. High 90s and even triple digit temperatures by day, and little cooling overnight have sprouted numerous health advisories: in short, stay cool, drink fluids, and keep an eye on the elderly, very young, and chronically ill. Cities such as Madison and Milwaukee have opened overnight cooling centers for people without air conditioning. Corn, a big water consumer, and other crops are suffering for lack of rain.
With dry vegetation comes a very high risk of grass and forest fires. The Department of Natural Resources has banned most outdoor burning in 11 counties until enough rain moistens vegetation--described as “a series of significant, soaking rain events” by one DNR expert. Cities cancelled and postponed fireworks for the Independence Day holiday, despite being exempt from the DNR restrictions, citing fire concerns. Rhythm and Booms went on as scheduled on June 30, though several grass fires did result (but were easily contained).
Meanwhile, the heat and drought are driving another problem: increased water use. Between taking over for nature by watering plants (which need more water because of faster evaporation rates), drinking extra water, and the extra showers, kiddie pools, and other means of keeping cool, Madison residents and businesses drew 1.09 billion gallons from City of Madison Water Utility wells in June--more than a tenth of the water used for the entirety of 2011.
In response, the City of Madison is urging citizens to conserve water by watering gardens during the coolest parts of the day (to avoid waste by evaporation), taking shorter showers, washing clothes and dishes with only full loads, and ceasing watering lawns entirely (established lawns can survive several weeks without water, and will only look dead). The city’s wells and reservoirs have a limited capacity: if citizens draw much more than 50 million gallons a day, there’s a chance a pump could break down, reducing capacity further and causing a drop in water pressure system-wide.
“Everything’s interconnected,” said Gail Gawenda, public information officer for the water utility. “At night we fill the reservoirs. Then during the day when people are using it a lot, it goes down. Some wells pump constantly, but it’s harder to keep up the filling and keep the water pressure going when people are watering their lawns.”
“We just don’t have the redundancy we need if something breaks,” said Joe Demorett, the utility’s water supply manager.
He said a usual summer day is closer to 40 million gallons, and the city pumps more water in July and August in a normal year. Demorett said there have been days that have approached the threshold: on June 20th, the city pumped 44.5 million gallons, and the seven-day average between June 27 and July 3 was 42 million gallons. Demorett said if the city starts seeing consecutive 45 million-gallon days, they’ll likely issue more requests for voluntary conservations; consecutive 50 million-gallon days will merit mandatory measures such as alternate-side watering.
“Once we hit 50, it might drain them down too far during the day,” Demorett said. “We like to keep them full in case there’s a fire, too.”
There’s not much danger of actual water shortage in Madison, at least not anytime soon: the city’s wells are drilled into the deeper of two underground aquifers, and though the total quantity of water available in the state’s aquifers isn’t known, Gawenda says the wells are likely good for decades of dry years. At the same time, DNR Program Manager for Groundwater Mary Ellen Vollbrecht said, not everyone can count on a steady water supply right now, especially private landowners whose wells are often less deep. “Shallower wells are going to be a lot more susceptible and might be affected by both the dry weather and increased pumping,” Vollbrecht said. “Overall, Wisconsin has had plentiful water supplies, but we can see even these short-term droughts, floods, and changes in use can have an effect on some wells in some places.”
Furthermore, she said, pumping water takes electricity, and any increase in water use will also bump up electricity costs.
Relief on the heat front, at least, is in sight: daytime highs below 90 are predicted to hit starting Saturday. But what about rain? About the same as we’ve been seeing: chances of storms over the weekend, with the probability of rain hovering between 20 and 30 percent. So while people might find themselves needing less water because of cooler temperatures, there’s nothing yet for gardens and parched crops to look forward to, and both burn restrictions and (voluntary) water conservation are likely to remain relevant.
“The only good news is there’s going to be a cold front coming through so the temperature should be dropping,” said National Weather Service forecaster Rudy Scharr.
Whether Southern Wisconsin will see continued drought in July and August, months already normally drier and hotter than June, is mostly unknown: the National Weather Service’s 90-day forecast indicates the chances are higher than not for a warmer-than-average July through September. And for precipitation, there’s about an even chance of either a drier, wetter, or normal end of summer, Scharr said. Long-range forecasts rely on broader climate indicators, such as wind patterns, sea surface temperatures, and ocean currents.
And what about future years? Climatologists have been vocal in saying this weather--like other droughts, wildfires, and other unusual events nationwide this year--fits the pattern predicted by long-term climate change, and years like this one are likely to recur.
Christie Taylor (@ctaylsaurus) covers science, environment, and, depending on the season, state politics for dane101. She verbs a lot of nouns, including rollerskates, radio, and Kurt Vonnegut. A Madison native, she's not sure she'll ever quite manage to leave Wisconsin, and that's just fine by her. Contact her at firstname.lastname@example.org.