online_usgs_floods_california:   USGS methods for determining magnitude and frequency of floods in California QT = a A bP cE d Gotvald, A. J., N. A. Barth, A. G. Veilleux, and C. Parrett. 2012. Methods for determining magnitude and frequency of floods in California, based on data through water year 2006: U.S. Geological Survey Scientific Investigations Report 2012 - 5113. Waananen, A. O., and J.R. Crippen. 1977. Magnitude and frequency of floods in California: U.S. Geological Survey Water-Resources Investigations Report 77 - 21. INPUT DATA: Stream (optional):   Units:    U.S. Customary SI (metric)< (U.S. Customary units) (SI units) Source:    2012 Report 1977 Report Hydrologic region:     [1] North Coast (Region 1) [2] Lahontan (Region 2) [3] Sierra Nevada (Region 3) [4] Central Coast (Region 4) [5] South Coast (Region 5) [6] Desert (Region 6) Return period:     All 2 5 10 25 50 100 200 500 [For the 1977 Report, the maximum return period is 100-yr] Drainage area A (mi2) (km2) :    2012 Report:  [All] 1977 Report:  [All] Mean annual precipitation P (in) (cm) :    2012 Report:  [1] [2] [3] [4] [5] 1977 Report:  [1] [3] [4] [5] Mean basin elevation E (ft) (m) :    2012 Report:  [3] 1977 Report:  [1] *  [3] [4]   * May leave blank for the 100-yr return period. OUTPUT: Please enter input data and press 'Calculate'. ⇐ ⇐ ⇐ [You may leave any input variable blank if not needed by formula].   Your request was processed at  04:37:36 pm on October 30th, 2025   [ 251030  16:37:36 ]. Thank you for running online_usgs_floods_california.   Please call again.   [131002]