Jo Evans

Bypass flows are not water rights. They are conditions on the use of public land. Courts have upheld that the federal government has the authority to impose conditions on the use of federal lands, even if the conditions affect the exercise of a state water right.

A special use permit is required in order to operate a dam or diversion works on federal land. The federal land manager may impose a bypass flow requirement on the permit. Under low flow stream conditions, the operators may be required to close their head gates or to otherwise release water, allowing the water to bypass the diversion structure and simply remain in the stream. Unlike a state water right for an instream flow, a bypass flow is not a specified flow between 2 discrete points.

In a way imposition of a bypass flow requirement is comparable to a landlord placing requirements on your apartment lease. You occupy the apartment, but you do not own it, and there are sets of requirements with which you must comply for the period of the lease. If you seek to renew the lease, there may be different requirements. Times have changed. The rent may be higher. If you do not want to pay the increased rent, you do not have to renew the lease, even if you fixed the screen door and painted the living room.

Owners of dams and diversions can be "tenants" on public lands, but like any tenant they are expected to ensure that their operations do not harm the underlying property. In this case, that means they must operate consistent with long term conservation of the public lands belonging to their landlord, the people of the United States.

A Bypass Flow requirement means that under certain conditions, a federal land manager may direct the operator of a dam or diversion works located on federal lands to allow a portion of the stream to "pass by." The bypassed water remains in the stream.