Reclamation Information Sharing Environment (RISE)

As part of the Klamath River Basin Revised Natural Flow Study, the Daily Lake Evaporation Model was used to simulate daily open water evaporation on water bodies throughout the Upper Klamath River Basin. Modeling methodology, results, and analysis are documented in a technical memorandum. Daily evaporation rates and volumes were estimated for all large waterbodies in the upper Klamath River Basin that have significantly changed between pre-development and water years (WY) 1981–WY 2020. A large effort was made to quantify the uncertainties related to the estimated evaporation rates and volumes which arose from biases in forcing data and unknown waterbody mean depths. The overarching purpose of the Klamath River Basin Revised Natural Flow Study is to apply current science, methods, and tools to develop natural streamflow estimates, while addressing known limitations of previous estimates and incorporating recommendations provided by the National Research Council. The natural streamflow estimates may be used for habitat suitability studies, drought planning, streamflow forecasting, water operations studies, and other water resource investigations. Furthermore, this study provides numerical modeling tools that can be used for future assessments.