CONNstruction - Winter 2015 - (Page 7)

newsandviews The Big Dam Challenge By Don Shubert CCIA President Once every four years, the American Society of Civil Engineers releases an assessment of the condition of the nation's infrastructure in a report card. Categories within this report include several water-related areas, such as ports, wastewater, levees, drinking water, inland waterways, and dams. Two areas that could use more attention are dams and levees. Since 1998, the grades have been near failing, due to delayed maintenance and underinvestment. The condition of Connecticut dams mirrors the national trend. Out of the 4,646 dams in inventory, about 277 are classified as significant-hazard dams and 267 are high-hazard dams. Dams earned a grade of D. The average age of the 84,000 dams in the country is 52 years old. The nation's dams are aging and the number of high-hazard dams is on the rise. The hazard classification of a dam is determined by considering: the height of the dam; the size of the pond; the location of structures below the dam; and the expected mode of failure for the dam. Based on these factors, the likelihood that human life or property damage would occur during the hypothetical breach of a dam determines the classification. The challenge with dams is two-fold. The first challenge is facing years of age and deterioration. The second challenge is presented by commercial and residential development below the dams. Many dams were built as low-hazard dams protecting undeveloped agricultural land. However, growing populations and greater development below dams have been increasing the potential risks associated with a failure. This aspect of the challenge has pushed the overall number of highhazard dams to nearly 14,000 in 2012. Nationally, the number of deficient dams is currently more than 4,000, which includes 2,000 highhazard dams. The Association of State Dam Safety Officials estimates that it will require an investment of $21 billion to repair the aging, high-hazard dams. The condition of Connecticut dams mirrors the national trend. Out of the 4,646 dams in inventory, about 277 are classified as significant-hazard dams and 267 are high-hazard dams. Levees fared worse than the dams, earning a grade of D-. The nation's estimated 100,000 miles of levees can be found in all 50 states and the District of Columbia. Many of these levees were originally used to protect farmland, but their uses have been expanded and are now increasingly protecting developed communities. The reliability of these levees is unknown in many cases, and the country has yet to establish a National Levee Safety Program. The cost to repair or rehabilitate these levees is roughly estimated to be $100 billion by the National Committee on Levee Safety. Connecticut currently has 14 sites on the national priorities list, and approximately 29 miles of levees according to the current FEMA Midterm Levee Inventory. An example that stands out for levees in need of attention in Connecticut is the flood protection system along the banks of the Connecticut River in East Hartford and Hartford. This system is the largest of its kind in New England and represents one of the largest flood control systems on the East Coast. As with many levees around the country, substantial development has occurred behind this levee over the years, increasing the risk associated with a substantive failure. In Hartford, for example, approximately 20 percent of its land area is in the levee protected zone, most of which is comprised of prime commercial, institutional, and residential properties. Other infrastructure that would be impacted includes the Interstate Route 84/91 interchange, the Metropolitan District regional sewage treatment facility, Brainard Regional Airport, and an aviation fuel supply line serving Bradley Airport and Westover Air Force Base. While it is clear that we have a significant backlog of overdue maintenance across all infrastructure systems, the dam and levee challenges should not be overlooked. The risks of failures continue to compound with time. connstruction / WINTER 2015 / 7

Table of Contents for the Digital Edition of CONNstruction - Winter 2015

The Big Dam Challenge
MDC’s Office of Diversity: Promoting
Call Before You Dig – System Enhancement!
Cleaning Water, Creating Jobs
Connecticut’s New Port Authority Key to Economic Growth
40-Year Old Treatment Plant Gets Royal Flush Upgrade
What You Need to Know About WOTUS
AGC of Connecticut Industry Recognition Awards
Connecticut Environmental & Utilities Contractors Association Annual Fall Meeting
Diggers Mixers Fixers – 2015 Golf Outing!
CCPC – 2015 Summer Outing!
2015 Young Contractors Forum bus trip to the new Yankee Stadium
2015 YCF Fall Membership Meeting
Index to Advertisers/ Published

CONNstruction - Winter 2015