美国饮用水的质量和数量都受到严重威胁。关键流域土地上不受控制的开发在许多方面威胁着我们的水源。随着道路、屋顶和停车场的修建，原本可以补给蓄水层的雨水变成了径流，污染了地表水和地下水。与此同时，人口增长对现有水资源的需求也越来越大。供水管理者越来越意识到，流域保护可能是保证饮用水质量和数量的最好、最便宜的方法。本文简要论述了流域保护的重要性及其诸多好处。

The quality and quantity of America's drinking water are seriously at risk.Uncontrolled development on critical watershed lands is threatening our watersupplies in many ways. With the construction of roads, roofs, and parking lots,rainwater that once would recharge aquifers instead becomes runoff, pollutingsurface and groundwaters. At the same time, population growth is putting greaterdemands on existing water supplies. Water supply managers are increasingly comingto realize that watershed protection may be the best and cheapest way toguarantee both the quality and quantity of drinking water. This paper brieflydiscusses the increasing importance of watershed protection and its manybenefits.