The Conservation Reserve Program, a land retirement program designed to remove from production 40 to 45 million acres of highly erodible cropland, may generate an estimated $3.5 to $4 billion in water quality benefits. Potential benefits include lower water treatment costs, lower sediment removal costs, less flood damage, less damage to equipment which uses water, and increased recreational fishing. Benefits were estimated with a set of procedures that approximated the physical, chemical, biological, and economic links between soil erosion and water use.