Past-President, American Institute of Hydrology, 2007-08

President, American Institute of Hydrology, 2005-06

Past-Chairperson, Groundwater Management Committee, Amer. Soc. of Civil Engrs., 2005-06

U.S. National Representative to the International Assoc. of Hydrological Sciences, 2003-08

Member, U.S. National Committee of the Internat. Union of Geodesy and Geophysics, NRC, 2003-08

U.S. National Correspondent to the International Assoc. of Hydrological Sciences, 2003-08

Chairperson, Groundwater Management Committee, Amer. Soc. of Civil Engrs., 2003-05

President-Elect, American Institute of Hydrology, 2003-04

Vice President, International Commission on Water Resources Systems, IAHS, 1999-08

Chairperson, Organizing and Tech. Committees, Internat. Symp. on Integrated Water Resour. Manag’t, 1999-00

Chairperson, Policy Sciences Technical Committee, American Geophysical Union, 1998-03

Interim Associate Director, University of California Center for Water and Wildland Resources, 1998-99

Chairperson, Research Committee, The Universities Council on Water Resources, 1997-00

Member, Board of Directors, The Universities Council on Water Resources, 1997-00

Director, Hydrology Program (Vice Chair of the Dept. of Land, Air and Wat. Resour.), UC Davis, 1996-98

Chairperson, Awards Committee, WRPM Div., Amer. Soc. of Civil Engrs., 1994-95

Past-Chairperson, Comm. on Water Resources Systems, Amer. Soc. of Civil Engrs., 1994-95

Faculty Assistant, Office of the Provost, UC Davis, 1993-95

Chairperson, Comm. on Water Resources Systems, Amer. Soc. of Civil Engrs., 1993-94

Chairperson, Affinity Group on Groundwater Modeling, WRPM Div., Amer. Soc. of Civ. Engrs., 1990

Chairperson, Graduate Group in Hydrologic Sciences, UC Davis, 1989-92

Chairperson, Publications Comm., WRPM Div., Amer. Soc. of Civil Engrs., 1984-88

Chairperson, Graduate Group in Hydrologic Sciences, UC Davis, 1975-79