Antelope Valley Is Depleting Its Ground Water Supply, New Study Says : Development: The findings contradict a recent Los Angeles County report that said the region was not overdrafting its supplies.

Residents and businesses in the Antelope Valley, where water supply concerns are emerging as a threat to development, are already using far more ground water than nature can replenish even in wet years, according to a new study.

The findings, sponsored by a group of Antelope Valley water agencies, directly contradict a Los Angeles County report last month that said the region was not overdrafting its ground water.

The conflicting assessments are expected to fuel more debate on the issue.

The drought has reminded local officials that they cannot plan development in the region by relying solely on imported state water that might not always be available.

State deliveries were cut 80% this year.

Ground water is the region’s only other consistent source of water.

But concerns about its use skyrocketed this year with discoveries of cracking and slowly sinking ground in Lancaster and nearby at Edwards Air Force Base.

Scientists believe the sinking is due to historic overdrafting of ground water.

That has led to calls for slowing the pace of new development.

The new study estimates that the valley used at least 100,000 acre-feet of ground water last year for homes, businesses and irrigation.

That is about 60,000 acre-feet more than the projected 40,700 acre-foot average recharge capacity of its underground aquifers, the study said.

For the current year, the overdraft of ground water could rise from 60,000 acre-feet to more than 100,000 acre-feet because of the cutbacks in state water deliveries, the study said.

An acre-foot of water is nearly 326,000 gallons.

The Antelope Valley United Water Purveyors, the group of 17 water agencies in the valley that sponsored the study, said the conflicts between the new findings and the county report reinforce the need for an impartial survey of ground water resources.

The county, the cities of Lancaster and Palmdale, and water agencies in the region have been considering funding such a study, but have not reached agreement.

The water purveyors group said the U.S. Geological Survey should conduct the study.