New Approaches to Inspect Water Pipelines Running under Rivers, Lakes, Levies, and Critical Transport Infrastructure

Utilities often do not know the actual condition of water distribution and transmission main infrastructure running under bodies of water or near/under critical infrastructure such as highways, railways and levees. These extensive and aging pipeline infrastructure assets often have no redundancy and in the event of a water main rupture pose very serious consequences in terms of environmental damage, service disruption and cost to repair surrounding infrastructure. A growing number of utilities are recognizing the need to inspect this critical infrastructure to minimize their risk exposure and ensure efficient water network operation. As part of their water network, the Corpus Christi Water Department operates a 24" diameter steel transmission main (a combination of cement lined steel and AC pipe) which runs under a shallow portion of the Corpus Christi Bay, connecting the main land to Padre Island which is a popular tourist destination featuring resorts, hotels,marinas, and pristine beaches. The transmission main was installed in 1960s and runs a total length of 24,000 feet under 4-8 feet of water/mud on the bay floor and throughout the island delivering potable water. There is curently no redundant water main to supply the island in the event of a rupture or service interruption. Due to the extensive cost to replace or repair the transmission main, the Corpus Christi Water Department required a reliable method to evaluate the condition of the pipeline to help make and justify their capital infrastructure plans and to ensure reliable water supply to the island.