NID taps specialized nitrox diving tech for high-altitude dam repair, advances clarifier restorations

NID taps specialized nitrox diving tech for high-altitude dam repair, advances clarifier restorationsThe Nevada Irrigation District has awarded a contract to replace an 86-year-old valve at the remote French Dam, capitalizing on a contractor's specialized gas mix certification that drastically reduced project costs compared to competing bids.

Associated Underwater Services won the $167,543 French Dam valve replacement contract, defeating alternative bids that reached up to $1.8 million.

The low bid was driven by the contractor's certification to use a Nitrox gas mix, allowing divers up to 1.5 hours of bottom time at an 80-foot depth.

The board also approved two clarifier restoration contracts totaling $843,465 to Redwood Painting Company for the Lake Wildwood and North Auburn treatment plants.

NID staff confirmed they are actively pursuing Proposition 4 dam safety funding for the Scotts Flat spillway project.

The Nevada Irrigation District (NID) Board of Directors has approved a suite of infrastructure rehabilitation contracts, highlighted by a highly competitive underwater repair project at the historic French Dam. During the June 24 meeting, the board awarded a $167,543 contract to Associated Underwater Services (AUS) for the French Dam Hydraulic Line Replacement and Inlet Gate Actuator Refurbishment. The project will replace an 86-year-old hand pump and valve system located approximately 80 feet below the surface of the 166-year-old reservoir. Directors expressed surprise at the massive spread in bid prices, which ranged from the winning $167,543 bid up to $1.8 million. Director of Engineering Gabe Aranow explained that AUS's competitive advantage stemmed from a special certification allowing their divers to use a Nitrox gas mix rather than ambient air. This specialized mix permits up to an hour and a half of dive time per diver per day at that depth, compared to just 30 minutes for competitors using standard air. Director of Power Systems Peter Ray noted that the district opted to replace the hand-operated valve in kind rather than automating it, as motorized actuators are less likely to withstand the aggressive winter environment at the site's 6,000-foot elevation. In addition to the dam work, the board awarded two fixed-bid contracts to Redwood Painting Company for clarifier tank restorations: $464,361 for Tank A at the Lake Wildwood Treatment Plant and $379,104 for Structure 2 at the North Auburn Treatment Plant. Addressing board concerns over a lack of built-in project contingencies for the clarifier work, Director of Maintenance Steve Prosser explained that the district's rigorous pre-bid processes eliminate the need for them. "These tanks and clarifier refacing, they go through many years of inspections," Prosser said. "We have professional third-party inspectors... so it's pretty much eyes open on this kind of project because it's not new construction. There are no surprises." Looking ahead to future capital needs, the General Manager's report confirmed that NID has hired a specialized grant writer to pursue state and federal infrastructure funding. A primary target is the upcoming Proposition 4 dam safety funding cycle, for which the district is positioning its Scotts Flat spillway project.