Despite Rain, Drought Persists

By David Brooks
THE CONCORD MONITOR
You might know this already but just in case, here’s a reminder: Just because we finally got a decent day or more of rain doesn’t mean the drought is over.

If you don’t believe that, go check the nearest stream.

For example, as of Tuesday afternoon the Soucook River at Pembroke Road was running at just 13.6 cubic feet per second, according to the U.S. Geological Survey stream gauge, a mere one-seventh as vigorous as last year’s tally of 91 cubic feet per second at this time last year. The difference at the Warner River in Davisville isn’t quite as dramatic but still something: Last year it had one-third more water in it: 4.13 cubic feet per second compared to 3.12.

The Merrimack River, which is controlled by a series of dams, is also way down: The gauge at Goffs Falls in Manchester is half the level it was at this time last year.

As of Tuesday, much of the Concord area was categorized as having moderate drought even though our precipitation hasn’t been too bad. Several communities in the area that depend on wells have instituted bans or limits on outdoor watering. Concord, which uses Penacook Lake as its main water supply, has not issued a ban but is asking people to conserve water.

Around an inch of rain fell on the city from Monday night through Tuesday, which puts us pretty near the average precipitation for the first six months of the year, according to data from the National Weather Service. As of the end of July we had almost 23 inches total compared to long-term average of 24.3 inches.

But that doesn’t count August, which had been very dry up until Monday and, importantly, hotter than usual. The string of days near or above 90 degrees have increased evaporation and dried out the soil. The latter is important because soil in drought conditions does not absorb water well, so when rain does come, more of it runs off, reducing the value to plants and the amount of water that seeps into the ground to recharge aquifers.

Also important is last winter’s below-average snowfall. Melting snow is important in New Hampshire, especially for aquifers, which helps explain official caution about water use even when rainfall totals may not be alarming.

But we’re better off in the Concord area than they are further south. Manchester and below are in severe drought and even extreme drought conditions because so many storms have passed north of them this year. And total precipitation in Boston and Eastern Massachusetts was more than 10 inches below average for the year, through Monday.

This week’s rains will help them a lot, although the combination of very heavy downpours and dry soils will create localized flooding with less water available for vegetation and drinking supplies than would otherwise be the case.

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