(a)
(1)
As part of updating The California Water Plan every five years pursuant to subdivision (b) of Section 10004, the department shall conduct a study to determine the amount of additional water needed to meet the state’s future water needs and to recommend programs, policies, and facilities to meet those needs.
(2)
As part of the 2033 update to The California Water Plan, the department shall update the required planning target pursuant to subdivision (f) for 2050.The
target shall consider the identified and future water needs for all beneficial uses, including, but not limited to, urban uses, agricultural uses, recreational uses, tribal uses, and the environment, recognize the impacts of climate change on the state’s water resources, ensure
safe drinking water for all Californians, and reflect statewide, regional, and local planning efforts. In establishing the long-term supply target, the department shall analyze current and future water needs trends, including identifying additional water necessary to sustain public trust resources. Nothing in this paragraph shall require the state water board or regional boards to update water quality control plans in order for the department to update the required planning target described in subdivision (f).
(3)
Subsequent updates of the plan shall include a range of water supply targets that consider future scenarios with a 50-year planning horizon at a watershed scale.
(b)
The department shall consult with the advisory committee established pursuant to subdivision (c) of Section 10004 in carrying out this chapter.
(c)
On or before December 31, 2027, and one year prior to issuing each successive update to The California Water Plan, the
department shall release a preliminary draft of the assumptions and other estimates upon which the study will be based, to interested persons and entities throughout the state for their review and comments. The department shall provide these persons and entities an opportunity to present written or oral comments on the preliminary draft. The department shall consider these documents when adopting the final assumptions and estimates for the study. For the purpose of carrying out this subdivision, the department shall release, at a minimum, assumptions and other estimates relating to all of the following:
(1)
Basin hydrology, including annual rainfall, estimated
unimpaired streamflow, depletions, and consumptive uses.
(2)
Groundwater supplies, including estimates of sustainable yield, supplies necessary to recover overdraft basins, and supplies lost due to pollution and other groundwater contaminants.
(3)
Current and projected land use patterns, including the mix of residential, commercial, industrial, agricultural, and undeveloped lands.
(4)
Environmental water needs, including regulatory instream flow requirements, nonregulated instream uses, and water needs by wetlands, preserves, refuges, and other managed and unmanaged natural resource lands.
(5)
Current and projected population.
(6)
Current and projected water use for all of the following:
(A)
Interior uses in a single-family dwelling.
(B)
Exterior uses in a single-family dwelling.
(C)
All uses in a multifamily dwelling.
(D)
Commercial uses.
(E)
Industrial uses.
(F)
Parks and open spaces.
(G)
Agricultural water diversion and use.
(7)
Opportunities for demand management.
(8)
Evapotranspiration rates for major crop types, including estimates of evaporative losses by irrigation practice and the extent to which evaporation reduces transpiration.
(9)
Current and projected adoption of urban and agricultural conservation practices.
(10)
Current and projected supplies of water provided by water recycling and reuse.
(11)
Current and projected water and infrastructure needs of disadvantaged communities, as defined in Section 79505.5, served by public water systems, state small water systems, and individual domestic wells, including, but not limited to, access to safe and affordable drinking water and sanitation, water quality, and water supply.
The department may incorporate by reference the State Water Resources Control Board’s Drinking Water Needs Assessment or other available relevant assessments or reports.
(12)
Climate change impacts by region and resulting water supply trends, including changes in timing and intensity of snowmelt runoff.
(d)
The department shall include a discussion of the potential for alternative water pricing policies to change current and projected water uses identified pursuant to paragraph (6) of subdivision (c).
(e)
This section does not require the department to update, or prohibit the department from updating, any data necessary to update The California Water Plan pursuant to subdivision (b) of Section 10004.
(f)
As part of the 2028 update to the plan, the department shall include an interim planning target of 9,000,000 acre-feet of additional water, water conservation, or water storage capacity to be achieved by 2040. This target may be achieved through strategies, including, but not limited to, a combination of the development of new or expanded surface or groundwater storage, conservation efforts, including the ongoing implementation of the Making Conservation a California Way of Life regulation pursuant to Article 1 (commencing with Section 965) of Chapter 3.5 of Division 3 of Title 23 of the California Code of Regulations, or the development of stormwater capture, graywater, recycled water, or other water supplies.
