text: i want web pages about irrigation canal lining and its life?   www.commercialshotcrete.com/commercial/canal/ www.usbr.gov/pn/programs/wat/canal.html www.geomembrane.com/techpapers/igscanallining.html www.iid.com/water/works-allamerican.html www.cwc.org/industry/ibp972.htm