An instream flow is a specific type of water right, as recognized by Colorado law.
Whereas most Colorado water rights involve uses that divert water from the stream, an instream flow allows water to remain in a stream to help protect the natural environment. The only entity that can legally hold such a right is the Colorado Water Conservation Board (CWCB).
How is the City of Boulder involved?
The city has donated several water rights on Boulder Creek to the CWCB for instream flow purposes, and can use those rights to boost flows in the creek.
The city and CWCB have agreements about instream flow on Boulder Creek, which allow the city to act as the CWCB’s agent and to coordinate with the state Water Commissioner if streamflows drop below protected levels.
How does the city monitor instream flows?
Streamgages maintained by the city and the state measure streamflow throughout the protected reaches of Boulder Creek. City and state staff and water users regularly monitor these data online and can use these data to inform water management decisions to protect streamflow.