The city council addressed the most impending threat to Graham’s water supply at its meeting Thursday morning by approving actions to re-engineer the system that pulls raw water from Lakes Graham and Eddleman.
A three-part response was approved in one motion by the city’s aldermen Thursday. The first part, a temporary response, is to extend a pump to a deeper point in Lake Eddleman from the current intake’s location, which will cost an estimated $300,000. City manager David Casteel hopes the project can be completed by August 1.
If current rain trends continue, the elevation of Lake Eddleman, where the city brings raw water into its treatment plant, could dip below the plant’s intake structure as soon as summer, 2015. The intake is at a lake elevation of 1,055 feet above mean sea level, or MSL, and as of Thursday, the lake was at a level of 1,062 MSL.
“Of course we hope that none of that happens, and we do get a rain,” said Casteel at the meeting.
Recently a rock and soil ridge was discovered just outside the intake structure at an elevation of 1,058 MSL, meaning that the current intake structure could be rendered useless as soon as May, 2015, according to a study that projects the lake’s depletion rate.
The study was presented by Scott Swanson of La Costa Environmental at the May 22 city council meeting.
”We’re thinking that elevation 1,060 is a decision point for us,” explained Casteel to the council. “We need to be doing something in order to ensure that we get adequate flow over that ridge into the water plant. Unless it rains significantly very soon, the existing raw water intake system could have its operations affected by the late summer of this year, and the inlet itself would not be operational, possibly within 12 months.”
Read the entire story in this weekend's Graham Leader.