Despite an aggressive preventative maintenance program in Central Iowa, water mains around Des Moines are breaking at a record number, Cold weather and corrosion of pipes have teamed up to cause pipe failures. The extreme drop in mercury drives frost penetration to a greater depth. Deeper frost penetration causes the corroded water mains to break. With expected warmer temperatures in the coming days, it can cause the frost line to move quickly and cause breaks as well.
The American Society of Civil Engineers’ 2013 grade for America’s drinking water infrastructure was a D, which is no surprise considering Des Moines Water Works has repaired a record number of main breaks in one month: 122 breaks in January. To date, Des Moines Water Works crews have repaired 200 main breaks, with as many as 12 in a single day.
The 10 year average for total main breaks in a year is 290. On average, half of the main breaks occur in the three winter months of December, January and February. The total number of main breaks in 2013 was 342. The highest number of breaks in one year was 365, set in 1988.
The average cost of a main break is around $5,000-7,000 for labor, materials and equipment. This does not account for the loss of water at a main break. The 2014 budget for emergency repairs is approximately $1.5 million. So far in 2014, Des Moines Water Works has spent approximately $1 million in repairing water mains. Any impact of this year’s main break experience will be analyzed when determining the 2015 water rates.
Though largely out of sight and out of mind, Des Moines Water Works operates and maintains more than 1,300 miles of underground water mains distributing finished drinking water to homes and business in Des Moines and surrounding communities. The pipes in the distribution system are made from cast iron, concrete and plastic and also vary in size, from half-inch diameter service lines to 48-inch diameter transmission mains. Pipes installed between 1940 and 1960 are leading to most of the main breaks in Des Moines. The oldest pipe (circa 1900), which can be found in Downtown Des Moines, is some of the best in the distribution system.
“While every main break is different, fixing it quickly and safely are top priorities,” said Bill Stowe, CEO and General Manager, Des Moines Water Works. “Our goal is to minimize disruption to our customers who live, work and commute in the area.”
Des Moines Water Works invests millions of dollars each year in infrastructure improvements. The 2014 capital improvements budget includes $2.2 million for water main replacement within the Des Moines water distribution system. These funds will be used to replace water mains that have reached their useful life expectancy – water mains with a high occurrence of breaks.