Another kind of water woe

Nicholas Christie-Blick

Community View Journal News Nov.4, 2005

After more than 10 inches of rain in one recent week, it might be concluded that Rockland dodged the latest drought bullet. However, a mismatch between the water supply and a burgeoning population continues to be a serious problem, one that is yet to receive more than cursory attention from planning boards and elected officials at all levels. As was the case in 1995, a mere five months of deficient rainfall (39 percent below normal for the months of May through September) after an exceedingly wet year (almost 60 inches in 2004) was enough to trigger concerns about the water supply.

With the level of Lake DeForest falling to only 53 percent of capacity in early October, after having been essentially full for well over two years, rainfall that was more than 60 percent below normal for August and September more than met the criterion needed for the county Health Department to impose Stage 1 restrictions on domestic water use.

Following the drought of 2001, and nine months of Stage 3 water restrictions in 2002, a study of the historical rainfall record revealed that conditions comparable to those leading to the declaration of emergencies in Rockland in 1995, 1999, and 2002 recur at intervals of three to five years (Lyon, Christie-Blick and Gluzberg, Journal of the American Water Resources Association 2005). The summer of 2005 was entirely consistent with that pattern.

As each new property development, subdivision or zone change is approved without regard to the consequences for the water supply, the situation will become increasingly fragile. Residents of New Orleans discovered in August that ignoring the inevitable is a strategy that works only so long. The Rockland equivalent of inadequate levees is a return to the severe multi-year drought conditions of the 1960s with a population that is already more than twice as large drawing upon essentially the same supplies.

The writer is professor of Earth and Environmental Sciences,

Lamont-Doherty Earth Observatory of Columbia University.