The Maine Land Use Regulation Commission will vote Thursday on an application by Cherryfield Foods Inc. for a five-year permit to irrigate 5,517 acres of blueberry land in the watersheds of three Washington County rivers where Atlantic salmon are an endangered species.

Irrigation can double or even triple the yield per acre on blueberry fields and is particularly critical during dry years on the thin soils of the Washington County blueberry barrens.

Cherryfield Foods has been watering its blueberries under year-to year permits pending the completion of Maine’s water use management plan.

The purpose of the water use plan is to assure that irrigation withdrawals do not interfere with the water needs of Atlantic salmon.

A final draft was submitted earlier this month to Maine’s Land and Water Resource Council, the group of state agency heads that oversees the Maine Atlantic Salmon Conservation Plan.

LURC staff members are recommending that their board issue Cherryfield Foods a five-year permit on condition that the company continue to monitor the water levels in the 18 ponds, rivers and streams that supply the irrigation water.

A 1998 study, commissioned by the water use management committee, determined the minimum flows that salmon require in the Machias, Narraguagus and Pleasant rivers, and Cherryfield Foods is prohibited from pumping when water levels drop to those minimums.

That requires constant monitoring. And last year, according to the company’s permit application, Cherryfield Foods spent $1,070,727 on the mechanics of irrigation and another $499,758 on hydrologic monitoring by Eco-Analysts, an environmental consulting firm.

All of those reports were submitted to LURC, and staffers are determining whether the company violated its permit on five days last year, when Cherryfield Foods continued to pump from the Mopang Stream after water levels dropped below the minimum flow.

The permit application the LURC board will consider this week includes a number of changes from the current permit.

The company wants to extend the period for water withdrawals, moving the start of the irrigation season from June 1 to May 1.

The minimum flow study was confined to the amount of water that salmon in the rivers need during June, July, August and September. May is the time that salmon smolts – juvenile salmon that are ready for salt water – leave their native streams for the ocean.

May is also the time that adult salmon begin returning from the ocean to spawn in their natal streams, and the flow study did not address the amount of water the salmon need for those activities.

Several reviewers of the Cherryfield proposal, including the Maine Atlantic Salmon Commission, Trout Unlimited, the Natural Resources Council of Maine and the Atlantic Salmon Federation, expressed concern about the earlier start to the season.

Marcia Spencer Famous, LURC’s project analyst for the Cherryfield Foods application, said the staff is recommending that the company be permitted to begin pumping water from ponds on May 1, but not from streams.

Several of the changes the company is proposing in this year’s application met with support from reviewers, particularly the decision to move a pumping station on Mopang Bend downstream to protect salmon habitat and to stop direct withdrawals from the Pleasant River. The company also is proposing to develop wells to replace the Mopang Stream as a water source.

LURC staff noted those changes in the recommendation, saying that the company continues to search for alternatives to surface water. Cherryfield Foods has two well applications pending with LURC.

One group that is not happy with the Cherryfield Foods application or the company’s request for a five-year permit consists of the camp owners on Schoodic Lake, one of the water bodies that Cherryfield Foods uses for irrigation.

Approximately 100 camp owners petitioned LURC to deny the company permission to continue withdrawals from Schoodic Lake until an independent study could determine the effect that withdrawals have on the lake.

LURC responded to Schoodic camp owners’ concerns last year by prohibiting the company from pumping out of the lake once the water level dropped a foot below the high-water mark. But some of the camp owners say the loss of that amount of water continues to be a problem, affecting their beaches and docks.

The LURC meeting will take place at 8:30 a.m. Thursday, April 26, at the Rangeley Inn Banquet Hall, Main Street, in Rangeley.