Drought Brings Challenges To City Water Departments

By Jeff Griffin, Senior Editor | May 2012, Vol. 67 No. 5

Failed crops drooping over dry, rock-hard soil backed by record heat . . . dried lake beds and farm ponds . . . reservoirs falling to dangerously-low levels . . . wildfires burning tens of thousands of acres, consuming everything in their path . . .

And the list goes on.

In many areas, lack of rainfall was accompanied by intense heat that set records during the summer of 2011.

For 2012, an unusually mild winter and early spring with unseasonal storms has people wondering what the coming summer will bring.

While many effects of the drought are easily seen, the underground utility infrastructure of drought-stricken cities suffered major damage last summer as dry soils shifted, causing water mains to rupture. City crews and contractors were busy repairing water line breaks, a time-consuming and costly task.

It is not an overstatement to say utility crews and contractors pressed into service during the crisis performed at heroic levels.

For example, the city of Houston typically experiences 12,000 water line breaks a year in its 7,500-mile transmission and distribution system, said Alvin Wright, senior staff analyst and public information officer, Houston Public Works and Engineering Department. In 2011, there were17,800 breaks.

Conditions worsen
From February through May of 2011, the area experienced only 3.1 inches of rain, said Wright. The 30-year average for this period is 14.41 inches. Extremely high temperatures also were a factor. On Aug. 27, 2011, the temperature rose to 107 degrees Fahrenheit -- the highest ever recorded temperature in the city of Houston.

“Typically, our department receives 50 to 60 new breaks daily and is able to repair a leak within four days,” said Wright. “However, due to the high number of breaks experienced during the summer of 2011, the number climbed to an average of 100 per day during August and September and repair time spiked to eight days.”

Wright said the types of pipe that ruptured most often were asbestos/cement (A/C), followed by cast iron and PVC. Estimated failure rates for asbestos/cement pipes were 75 percent; cast iron, 20 percent, PVC and other, 5 percent.