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ERS 100 EXAMI FALL 1998 M. E. Grismer Read each question carefully and then logically reason through your answer. Be sure to write down all of your work for generous partial credit. Please also report your answer in a box using the units specified in the ( ) of each problem statement. Good luck! (Points) (20) 1. (20) 2. 3. (5) (70) (5) (20) 4. (20) 5S. The Sacramento municipal wastewater treatment plant installed a free surface wetland treatment system for final metals removal and “polishing”. The system consists of 10 cells, each 16 m wide x 380 m long and designed to operate with a free-water surface depth of approximately 0.2 m. Last month, the average flow into each wetland cell was 378 m’/d while the measured outflow averaged 354 nv/d. The water level dropped from 23.4 cm at the beginning of the month to 20,8 cm at the end. Previous tracer studies in the wetland resulted in recovery of 78% of the conservative tracer from the system. Estimate the ET (cm) from the wetland cells for the month. Given the sketch below, determine the density (gm/cm*) of the shaded fluid in the manometer. The clear fluid is water. For the idealized mature Douglas Fir watershed shown on the attached graph, determine the following: (a) the watershed area (ha); {b) The average rainfall depth (cm) across the watershed based on the Theissen polygon method; (c) Which gages (letter) have the greatest influence on the average rainfall depth? Explain. The total direct runoff volume associated with the 2-hr rainfall event of #36 was measured as 72,000 m3. Estimate the infiltration and depressional storage losses (cm) in the watershed for this storm. Is this a good storm from which to construct at UHG? Explain. Given the 2-hr UHG for the watershed on the attached graph, determine the peak discharge (m’/sec) from the watershed for the storm of #3b if the baseflow from the watershed is a relatively constant 0.5 m/sec. 
