American Society of Civil Engineers (Lifetime Member and Distinguished Member)

Past-Chair, Groundwater Management Committee, 2005-2006
Chair, Groundwater Management Committee, 2003-2005
Chair-Elect, Groundwater Management Committee, 2001-2003
Member, Environmental and Water Resources Systems Committee, EWRI-ASCE,     2000-
Member, International Cooperation Council, EWRI-ASCE, 2000-
Member, Publications Committee, Irrigation and Drainage Division, 1988-2008
Member, Groundwater Management Committee, Water Resources Planning and     Management Division, 1997-
Member, Task Committee on Sustainability Criteria, Water Resources Planning and     Management Division, 1994-2000
Member, Social and Environmental Objectives Committee, Water Resources     Planning and Management Division, 1993-2000
Member, International Activities Committee, Water Resources Planning and     Management Division,1991-2000
Member, Task Committee on Implementing Technical Cooperation in North     America, Water Resour. Plan. and Manag. Div., 1995-1997
Control Member, National Committee on Water Resources Systems, 1990-1995
Past Chair, National Committee on Water Resources Systems, 1994-1995
Chair, Awards Committee, Water Resources Planning and Management Division,     1994-1995
Control Member, Awards Committee, Water Resources Planning and Management     Division, 1993-1995
Chair, National Committee on Water Resources Systems, 1993-1994
Vice Chair, National Committee on Water Resources Systems, 1992-1993
Member, Task Committee on Streamflow Forecasting: Implications for Reservoir     Operations, Water Resources Planning and Management Division, 1990-1992
Secretary, National Committee on Water Resources Systems, 1990-1992
Control Member, Task Committee on Application of Systems Analysis Techniques to     Regional Groundwater Management, Hydraulics Division, 1989-1992
Chair, Affinity Group on Groundwater Modeling, 17th Annual National Conference,     Water Resources Planning and Management Division, 1990
Control Member, Task Committee on Water Resources Management Seminars with     Mexico and Canada, Water Resources Planning and Management Division,
    1987-1990
Chair, Publications Committee, Water Resources Planning and Management Division,     1984-1988
Member, Awards Committee, Water Resour. Plan. and Manag. Div., 1983-1988
Publications Representative, Committee on Water Resources Systems, 1982-1988
Member, Groundwater Committee, Irrigation and Drainage Division, 1979-1985
Vice Chair, Publications Committee, Water Resources Planning and Management     Div., 1982-1984
Member, Review Committee on Outstanding Paper Award (Norman Medal, Croes     Medal and Collingwood Prize), Water Resources Planning and Management     Division, 1975-1980

American Geophysical Union (Member and Fellow)

Member, Groundwater Committee, Hydrology Section, 2001-date
Co-Chair, Policy Sciences Committee, Hydrology Section, 1998-2003
Member, Education and Human Resources Committee, 1984-1986, 1992-1994

American Water Resources Association (Member, Fellow and Honorary Member)

Member, Technical Program Committee, 2001 Special Conference, 2000-2001
Member, International Affairs Committee, 1994-2000
Member, Awards Committee, 1992-1996
Member, Working Group on Groundwater, 1983-1996
Member, Working Group on Statistical Modeling, 1983-1996
Member, Working Group on Water Quality, 1983-1996
Member, Publications Committee, 1986-1994
Member, Selection Committee for Boggess Award, 1977-1991
Member, Conference Planning Committee, 1986-1989
Member, Editorial Board, Water Resources Bulletin, 1978-1982

American Institute of Hydrology (Member)

Past-President, 2007-08
President, 2005-06
President-Elect, 2003-04
Member, Board of Registration, 1990-1993
Certified Professional Hydrologist (Groundwater), 1990

The Universities Council on Water Resources (Member)

Lead Delegate, UC Davis, 1995-2008
Member, Board of Directors, 1997-2000
Chair, Research Committee, 1997-2000
Member, International Programs Committee, 1995-98

International Association of Hydrological Sciences (Member)

Vice President, Commission on Water Resources Systems, 1999-2008
Chair, Organizing Committee, International Symposium, 1999-2000
U.S. National Representative to the IAHS, 2003-08
U.S. National Correspondent to the AIHS, 2003-08
Co-Convenor, Symposium on Sustainable Water Management Solutions for Large     Cities, 2004

International Water Resources Association (Member)

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

American Association for the Advancement of Science (Member)

The New York Academy of Sciences (Member)

Tau Beta Pi, National Engineering Honor Society (Member)

Topical Editor, Groundwater, The Encyclopedia of Water Science, Marcel Dekker, Inc.,
     2000-date

Co-Editor, Sustainable Water Management Solutions for Large Cities, Publication no. 293,     International Association of Hydrological Sciences, Wallingford, U.K., 2005

Co-Editor, Integrated Water Resources Management, Publication no. 272, International     Association of Hydrological Sciences, Wallingford, U.K., 2001

Co-Editor, Regional Management of Water Resources, Publication no. 268, International     Association of Hydrological Sciences, Wallingford, U.K., 2001

Editor, Journal of Water Resources Planning and Management, ASCE, 1984-88

Editor, Subsurface Flow and Contamination: Methods of Analysis and Parameter Uncertainty,
    Monograph Series No. 8, American Water Resources Association, 1987

Editor, Proceedings of the National Symposium on Groundwater Hydrology,
    American Water Resources Association, 1967

Associate Editor, Hydrology Research, 2004-

Associate Editor, Hydrological Sciences Journal, 1999-05

Associate Editor, Journal of Hydrologic Engineering, ASCE, 1995-00

Associate Editor, Journal of Water Resources Planning and Management, ASCE, 1982-84

Associate Editor, Water Resources Bulletin, Amer. Water Resour. Assoc., 1982-88

Editorial Board, Iranian Journal of Water Resources Engineering, 1993-2008

Editorial Board, Scientia Iranica, 1992-2008