(1) The following reports contain acceptable methods for estimating evaporation losses:

(a) Joint Technical Working Group Report, Water Rights Compact Between the State of Montana and the Department of the Interior, Bureau of Land Management, November 1998;

(b) Estimation of Evaporation from Shallow Ponds and Impoundments in Montana, Donald E. Potts, Miscellaneous Publication No. 48, Montana Conservation and Experiment Station School of Forestry, University of Montana, Missoula, March 1988;

(c) Evaporation Pond Design for Agricultural Wastewater Disposal, USDA Soil Conservation Service, Montana Technical Note: Environment No. 7, February 1974;

(d) Evaporation from Lakes and Reservoirs, a study based on 50 years of weather bureau records, Minnesota Resource Commission, June 1942; and

(e) A standard USGS evaporation pan is acceptable. The standard pan is four feet in diameter and ten inches deep and measured daily.

(2) Deviations from the acceptable standards in (1) require additional information supporting the volume requested for evaporation losses.

(3) The department will determine the acceptability of other evaporation loss estimates on a case-by-case basis.