The Inyo-LA Water Agreement says that DWP can build new wells “in areas where hydrogeologic conditions are favorable and where the operation of that well will not cause a change in vegetation that would be inconsistent with the goals and principles” of the water agreement. As DWP gets ready to turn on a new Well on the edge of Lone Pine, citizens worry that the draw down will kill plants and trees and dry up private wells. Why take the risk, they say. DWP will turn on Well 416 February 1st for a test.
Inyo Water Director Bob Harrington said that the first step is to assess what harm 416 might cause. He said it can be pump tested for up to a month, although Harrington expects the trigger wells will cause a much shorter test period. When water goes down too far, the pump goes off.
Harrington said the pump rate is 1500 gallons per minute, which looms lower than the original rate. An earlier test of Well 416 when it was built showed some significant drawdown after only 24 hours of pumping, including a 6 foot fall of groundwater in a deep well. So, officials expect the triggers to blow on the 11 monitoring wells fairly quickly this time.
Next, DWP and Inyo will assess impacts and determine what the pumping will harm in what’s called the “zone of influence.” Harrington explained that the triggers which cause the pump to shut off are based on the current groundwater level and recent levels, allowing water to drop a couple of feet or so depending on the situation.
Well 416 could impact tribal wells, the Lone Pine town water wells and numerous private wells nearby. DWP hydrographers and Inyo Water Department staff will monitor the situation.
Harrington said Inyo, DWP, the Owens Valley Indian Water Commission and Lone Pine Tribe all worked on an agreeable protocol to test Well 416. Harrington said the keys to protect the environment during this test are a short duration of the test and an array of wells with drawdown triggers.
Asked about citizen concerns that Lone Pine already has a lowered groundwater table from over-pumping, Harrington said he would get back to us with more information on the state of Lone Pine’s underground.