 Starting in 2020, Castle Rock expects to begin treating sink, tap, and toilet water to drinkable water quality standards so that it can be reused.The town aims to achieve a goal of reliance upon renewable water resources for 75% of municipal needs by 2050 and, by 2020, about one-third of all water used in Castle Rock is expected to be from a reusable source.As of July 2019 Castle Rock, Denver, and Pitkin County are the first three Colorado municipal or county governments to adopt a state regulation governing greywater reuse.