DAM RENOVATION WORK AT Horsetooth reservoir in Colorado by the US Bureau of Reclamation (USBR) is on schedule and under budget. USBR is overseeing the US$85M project to modernise the reservoir’s four earthen dams. The price tag was recently revised from US$105M – largely because of a change in design plans for work on Horsetooth dam.

USBR originally planned to install a concrete cut-off wall through the dams middle, designed to prevent water seepage though the foundation of the dam. In April 2002, USBR officials changed that plan in favour of a clay blanket – a 0.6-0.9m clay and synthetic layer covering about 1.8ha near the base of the dam at its northwest corner. Crews have finished installing the clay blanket, and it comes at a saving of US$19M when compared with the cost of the concrete cut-off wall originally proposed.