Water Supply Assessment for
The Woodlands at Chanate
City Council
December 16, 2025
Claire Nordlie, Senior Water Resources Planner
Santa Rosa Water
2 Overview
• SB 610 – Water Supply Assessments
(WSA)
• The Woodlands at Chanate
• Water Demand & Supply Analysis
• How demand is calculated
• Compare demand to supply under three
scenarios
• Sufficiency Determination
• Recommendation
2 3
Water Supply Assessment (WSA),
Senate Bill 610
• Requires water suppliers to
• Analyze total projected water demand and supply for next 20 years over three scenarios:
• Normal year
• Single dry year
• Multi-dry years
• Determine sufficiency of water supplies for the Project
4 The Woodlands at Chanate
Rezoning to allow for:
• Low density
• Medium-low density
• A maximum of 660.5
units
5 Project Description
Project (Density) Acres
Allowable
Dwelling Units
Per Acre
Maximum
Dwelling Units
Neighborhood A (Low) 18.6 8 148.8
Neighborhood B (Medium Low) 20.9 13 271.7
Neighborhood C (Low) 30 8 240
Total 69.5 660.5
6 Projected
Demand
for
Woodlands
at Chanate
Projected
Supply for
Santa
Rosa
Sufficiency
Determination
Current
Water
Demand
for Santa
Rosa
Future
Water
Demand
for Santa
Rosa
7 Demand Projection Methodology
• Residential Equivalency Factors (REFs) - used to assess demands using a standard methodology across various land use classifications Example: 1,000 square feet of retail development equal to 1 REF • 1 REF = Average water use of one single-family home per year (65,345 gallons)
Source: 2010-2019 average single-family home usage (2020 UWMP, Appendix E Water Demand Analysis)
Number of
REFs
65,345
gallons per
REF
x Total
Demand=
8 Growth to Residential Equivalency Factors
Land Use Category
Net Project
Area
(square feet)
Net Project
Rooms/Studen
ts
Net
Residential
Units
REF Conversion
Factor REFs
Residential Detached - - 660 1 REF/unit 660
Residential Attached - - - 0.7 REF/unit -
Retail - - - 1 REF/1,000 SF -
Office - - - 1 REF/500 SF -
Industrial - - - 1 REF/1,300 SF -
Public/Institutional - - - 1 REF/500 SF -
Park/Public Landscape - - - 1 REF/2,819 SF -
Hotel - - - 0.75 REF/Room -
Education - - - 0.11
REF/Student -
Total N/A 660
9 Water Demand for Woodlands at Chanate
660 REFs 65,345
gallons/REFx 43,160,373
Gallons= or
132.5 acre
feet per
year
+
11 acre feet
(non-revenue water
and misc. water
sales)
=
7 acre feet
(existing
demand)
-
136.5 AFY
Total
Demand
10 Scenario One: Normal Year Supply (AF) in
2045
Supply
31,540
Demand
25,234
No
shortage
11 Scenario One: Single Dry Year Supply (AF)
in 2045
Supply
21,689
Demand
21,826
0.6 percent
shortage
12 Scenario One: Multi-Dry Year Supply (AF) in
2045
Supply
26,097
Demand
25,234
No
shortage
13 Water Shortage Contingency Plan
• Enacted during a water shortage
• Plan requirements, depending on stage enacted:
• Water waste patrols
• Limit flushing of system
• Restaurants only serve water upon request
• Hotels wash linens upon request
• No pressure washing
• Net-zero water demand impact from new building
• Water rationing
• Limited or no irrigation allowed
• Excess use penalty
14 Demand Management Measures
• Indoor and outdoor rebates
• Free toilet giveaway
• Free water-saving devices
• Irrigation scheduling tools
• Plant selection support
• Webinars and workshops
• Events
• Water Waste Ordinance
• Advanced Metering Infrastructure
15 Sufficiency Determination
The WSA finds that Santa Rosa has adequate
existing and projected water supplies to meet the
planned development of the proposed Woodlands
at Chanate, in addition to existing development,
with the implementation of demand management
measures in dry years as needed.
NOTE: WSA will be included in the EIR for
General Plan.
15 16
Recommendation
It is recommended by Santa Rosa Water that the Council, by resolution, approve the Water Supply Assessment for the Woodlands at Chanate. 17 Questions?