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

Water balances for the Colorado River mainstem complex, the Cienega de Santa 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 variability of mainstem discharge at the Southerly International Boundary (SIB) delimiting the United States and Mexico. In non-flood years, agricultural and municipal returns to the mainstem below SIB contributed 180% of mainstem discharge at SIB, but may not be sufficient to generate the floodstage discharge required by native riparian vegetation