2005 Urban Water Management Plan - Sonoma County Water ...

SECTION 4
WATER SUPPLY
The Agency distributes Russian River water and groundwater to its water contractors and other
Agency customers. Water from the Agency is distributed via its transmission system (as described in
Section 2) and is used by Agency water contractors and other Agency customers to meet, in part,
their water demands. This section describes the surface water and groundwater sources, quantities,
supply constraints, and the reliability and water quality of the Agency’s water supply sources.
Recycled water is described in Section 5. The plans of the Agency’s water contractors should be
consulted for details on their individual water supplies.
4.1 Surface Water
This section describes the physical constraints to the Agency’s surface water supply and the legal
background and constraints to this supply. As described in Section 2, the Agency receives its surface
water from the Russian River.
4.1.1 Physical Constraints
The capacity of the Agency’s transmission system is a physical constraint on the delivery of water to
some of the Agency’s contractors and other customers, particularly during high demand periods in
the summer months. This physical constraint is addressed by the Memorandum of Understanding
described in Section 4.1.2. Future water supply projections are dependent upon planned
infrastructure improvements being approved and constructed, as discussed in Section 4.5.
4.1.2 Legal Constraints
The Agency’s Russian River water supply is controlled and influenced by a variety of agreements and
decisions. This section of the plan describes the water rights held by the Agency and the various
agreements and issues that may influence the surface water supply.
Water Rights. Four SWRCB permits 3 currently authorize the Agency to store up to 122,500 ac-ft/yr
of water in Lake Mendocino and up to 245,000 ac-ft/yr of water in Lake Sonoma, and to divert and
redivert 180 cubic feet per second (cfs) of water from the Russian River at the Agency’s Wohler and
3 SWRCB Permits Numbers 12947A, 12949, 12950, and 16596.
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