The article is in three Sections. The first discusses the historic apportionment of the Colorado River between the Upper and Lower Basins and, ultimately, among the seven Basin states and Mexico. It also addresses possible future legal questions about the interpretation of laws apportioning the River's water. The second Section identifies the most significant uses competing for shares of the water. Agriculture, power production, municipal use, Indians, and instream needs for fish, wildlife and recreation all are competitors for use of the Colorado River. The Section analyzes the nature of future conflicts among those uses and the potential for accommodating some apparently inconsistent purposes. The final Section considers several approaches to maximizing the River's capacity to satisfy future demands. The approaches include storage, efficiency measures, controlling salinity, comprehensive consideration of all available water sources and interstate water marketing. The Section describes some ways in which the approaches may be used to resolve competing demands in the future.