A preliminary water balance for the Colorado River delta, 1992-1998

Water balances for the Colorado River mainstem complex, the Cienega de Sant a Clara, and El Indio wetlands were calculated for the Colorado River delta in Mexico for the period 1992-1998. Discharge for the mainstem complex was disaggregated into flood and non-flood years, reflecting the marked variab ility of mainstem discharge at the Southerly International Boundary (SIB) d elimiting the United States and Mexico. In non-flood years, agricultural an d municipal returns to the mainstem below SIB contributed 180% of mainstem discharge at SIB, but may not be sufficient to generate the floodstage disc harge required by native riparian vegetation. (C) 2001 Academic Press.