Biologists on Thursday expect to wrap up studies on the effect that low Provo River flows have on trout habitat.

Flow into the river from Deer Creek Reservoir, cut Tuesday from 100 cubic feet per second to 60 cfs, will be returned to 100 cfs Friday. The data will be combined with other studies of the same area, and a final report is expected to be completed by Dec. 1.Since Tuesday, biologists have been gathering data along two quarter-mile sections and an eighth-mile section of the river. Charlie Thompson, Utah Division of Wildlife Resources regional fisheries manager, said biologists are evaluating river depth and width, areas where fish are likely to feed and how much fish habitat likely would be lost if flow remained at 60 cfs.

In addition to wildlife resources biologists, researchers from the U.S. Fish and Wildlife Service, Bureau of Reclamation and Central Utah Water Conservancy District also are analyzing the impact on trout habitat and aquatic insects.

An environmental impact statement for the Bonneville Unit's Municipal and Industrial System of the Central Utah Project requires minimum flows of 100 cfs between Deer Creek Dam and the Olmstead Diversion Dam to protect the river's blue-ribbon fishery.

Last December, the Provo River Water Users Association ordered flow cut to 40 cfs because of concerns about low snowpack and possible water shortages this year. The Bureau of Reclamation, however, ordered flow increased again to 100 cfs.

Thompson said the three river sections were studied in February when flows were 100 cfs and again two weeks ago when flow was 200 cfs. One more study will be conducted next week when flows are 100 cfs.

Combining new data with information from previous studies, Thompson said, officials will develop a model for projecting the impact of varying flow levels on the river between Deer Creek Dam and Olmstead Diversion Dam.

"We'll take that model and use the information on fish habitat to tell us how much suitable fish habitat is available in each of those flows," he said. That knowledge also will give officials an indication of how much habitat would be lost if flows were reduced.

As part of this week's study, researchers also plan to electrically charge several river pools thought to attract fish "to make sure some of the areas we're calling habitat actually have fish in them." The charge temporarily stuns fish so researchers can count their numbers and record their size.