City of Manhattan Beach
Annual Water Supply and Demand
Assessment 2023
Public Works Department
Mission Statement
To build, maintain, and protect our small beach town
community with a passion for excellence
INTRODUCTION
In July 2022, the City completed the first Annual Water Supply and Demand Assessment utilizing the Department of Water Resources (DWR) guidance and worksheets, the City's Urban Water Management Plan, the Electronic Annual Report (EAR) data, and the Manhattan Beach Actual Demand and Supply Data from Fiscal year 22/23.
Furthermore, the Annual shortage report was prepared with the assumption of the State Water Resources Control Board's regulation and the drought emergency statewide. The final report did not anticipate a shortage for Fiscal Year 22/23. The City has prepared the Annual Water Supply and Demand Assessment for Fiscal Year 23/24 without drought emergency statewide restrictions.
CITY BACKGROUND
The City is located on the western edge of Los Angeles County, approximately 22 miles southwest of downtown Los Angeles. The City of El Segundo borders the City to the north, Hawthorne and R edondo Beach to the east, and the cities of Redondo Beach and Hermosa Beach to the south. The City comprises approximately 3.9 square miles of primarily residential land use. Commercial land uses are located along Highland Avenue, Manhattan Beach Boulevard, Sepulveda Boulevard, and Manhattan Village, located southeast of Rosecrans Avenue and Sepulveda Boulevard. Industrial land uses primarily consist of the Northrop Grumman and Raleigh Studios, located northwest of Aviation Boulevard and Marine Avenue.
The City provides water service to an area with a current population of about 34,668.
WATER USE CHARACTERIZATION
The City provides water service to individual “water use sectors.” These water use sectors include single-family and multi-family residential, commercial, industrial, and landscape.
WATER DEMAND
Over the past ten years, the City’s total water demands (including potable and recycled water) have ranged from 4,878 AFY to 5,924 AFY, with an average of 5,308 AFY. The City currently measures its water use through meter data and billing records.
Additionally, the City conducts an annual water loss audit to identify distribution system water losses. Water losses can result from pipeline leaks and inaccurate metering due to faulty meters. Water loss estimates are incorporated into the City’s projected water demands.
The City’s water demand projections incorporate water savings from implementing the new Automated Meter Infrastructure (AMI) and utilizing leak alerts to warn customers when they have a leak on the property and assist them in finding and fixing the leak.
Based on analysis developed as part of its Urban Water Management Plan (UWMP), the City will be able to provide sufficient water supplies to meet the projected water demands of its customers, including during a five consecutive year drought period.
WATER SUPPLY RELIABILITY
The City’s water supply sources include treated imported water from the Metropolitan Water District of Southern California (MWD), treated groundwater through the West Coast Basin, and recycled water supply from West Basin Municipal Water District (WBMWD). MWD is the regional wholesaler of imported water for most of Southern California, providing water to its member agencies through a regional distribution system. WBMWD is one of MWD’s member agencies that provides imported water to agencies in the South Bay portion of Los Angeles County, including the City. WBMWD provides imported water to the City at connection WB-04, located at Manhattan Beach Boulevard and Redondo Avenue. The City maintains a metered connection with WBMWD to receive treated imported water. The capacity of this connection is 15 cubic feet per second (cfs). Currently, the City gets imported water from a blended portfolio of State Water Project and Colorado River supplies.
The City owns two West Coast Basin wells and extracts groundwater from the two active wells. Per the West Coast Basin Judgement, the City has an adjudicated pumping right of 1,131 acre -feet per year (afy) from the West Coast Basin and allowance to pump up to 20 percent more of its annual entitlement. The City’s total annual groundwater production cannot exceed 1,357 afy. In addition, the City is allowed to lease West Coast Basin water rights from other West Coast Basin producers.
The City uses approximately 298 afy of recycled water supplied by the WBMWD’s recycled water system. The recycled water system is owned, operated, and maintained by WBMWD.
CLIMATE CHARACTERISTICS
In Manhattan Beach, the climate is warm and temperate, the summers are comfortable, arid, and clear, and the winters are long, cool, wet, and partly cloudy. Over the course of the year, the temperature typically varies from 50°F to 74°F and is rarely below 45°F or above 82°F; the City of Manhattan's annual precipitation averages 13.6 inches.
The weather conditions can directly impact the City's source of supply. The Colorado River Aqueduct has been suffering from multi-year drought conditions with record-low precipitation that can impact the water supply to the City of Manhattan Beach. Therefore, proactive actions by the City and WBWMD will be needed to address any potential water shortage due to climate change.
POTENTIAL SHORTAGE CONDITIONS
Since 88% of the City’s water supply is from a blended portfolio of State Water Project and Colorado River supplies, there is a potential for a water shortage associated with this source. For the first time, a Tier 2 water shortage was declared in August 2022; Lake Powell fell below the target elevation of 3,525, which resulted in Federal allocation cutbacks to Arizona, Nevada, and Mexico. This had not occurred since the late 1960s; therefore, the Bureau of Reclamation set 2023 Operating Conditions for Lake Powell and Lake Mead during a press release on August 16, 2022. For the first time, the Lower Basin Drought Contingency Plan included delivery cutbacks of 200,000 AF for California if Lake Mead’s elevation reaches 1,040 and 1,045 feet. At the end of April 2023, the Lake Mead elevation was at 1050 feet.
PROJECTED POPULATION GROWTH
The City has grown significantly since its incorporation in 1912; however, over the last few years, the population has decreased and is closer to what it was ten years ago. Although the population has varied over the previous ten years, the City's Community Development Department expects a steady population growth of about 2 percent over the next ten years.
Demand estimates will consider potential growth and new demands for the current year. To the extent available, updates were requested from the City's Community Development Department on anticipated development within the City's wat er service area for the current year. Without current development data, the City uses the growth- related demand increases based on the long-range projections made in the current UWMP.
ANNUAL WATER SUPPLY AND DEMAND ASSESSMENT PROCEDURES
The Annual Assessment will be conducted annually on or before July 1st and was submitted to the DWR beginning July 1, 2022. The Annual Assessment should include information for anticipated shortage s, triggered shortage response actions, compliance and enforcement actions, and communication actions consistent with the supplier's WSCP.
0 5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
2025 2030 2035 2040 2045
0 1,000
2,000
3,000
4,000
5,000
6,000
7,000
Years
Population
Acre-Feet - Water
Water Demand and Population Growth Projection
Water Demand Projection
Population Serve Projection
This section describes the specific steps and timing to complete the Annual Assessment such that it can easily be consistently followed each year by City staff.
Because of its reliance on imported water, the City's primary factor triggering a water shortage determination would be a determination of water shortage and related water supply curtailments made by WBMWD. The City's Annual Assessment will depend on coordination with WBMWD to evaluate imported water supply conditions and unconstrained demands. Additionally, this process includes considering weather, population growth, and policies to meet demand objectives.
TIMELINE FOR ANNUAL ASSESSMENT ACTIONS
Target Day Action
July to December Monitor water supply and drought conditions Monitor water demand
January to February
Obtain updates on WBMWD supply projections
Start water demand and supply assessment
Project potential next shortage levels
March to April
Make recommendation to Public Works Director
Confirm WBMWD supply assessment and evaluate City’s potential supply shortfall based on WBMWD’s anticipated water supply condition/stage
Initiate public outreach, coordinate drought messaging with neighboring retail water agencies and WBMWD as appropriate May to June
Prepare draft Annual Assessment and present to City Council for approval – if declaring a shortage
Finalize Annual Assessment and submit to DWR
Potentially declare water shortage and implement demand reduction and other shortage response actions
July to June Monitor customer response to water shortage messaging and other actions
By starting to plan in July, the City will get an early snapshot of conditions, assess the resources necessary to mitigate a supply shortage , and begin outreach to customers to manage demand. In February, significant actions are proposed when an initial estimate of a potential supply shortage is made. After confirming the supply assessment from WBMWD, updates will be provided to the City Manager in April, and the annual assessment will be finalized to present to the City Council in June. Depending on the findings, a water shortage may be declared by City Council, with demand reductions implemented in accordance with the City’s ordinance and the stages outlined in this WSCP.
KEY DATE INPUTS AND ASSESSMENT METHODOLOGY
This section describes the key data inputs and the Annual Assessment methodology used to evaluate the City’s water supply reliability for the coming year, considering the following year would be a dry hydrologic year.
EVALUATION CRITERIA
Given the City’s reliance on WBMWD water supply, the primary factor triggering a water shortage determination by the City during its Annu al Assessment would be if WBMWD declared a water shortage that would result in curtailment of WBMWD supplies. The City will coordinate closely with WBMWD to obtain updates on WBMWD supply projections early on and evaluate the City’s potential supply shortfall based on WBMWD’s anticipated water supply or shortage conditions.
CURRENT YEAR WATER SUPPLY
Current and future City water supplies are based on volumes purchased from WBMWD to meet actual customer demands. As part of the Annual Assessment, the City will obtain WBMWD water su pply projections to assess the City’s current year water supply. The City anticipates being able to purchase adequate WBMWD supplies to meet its demands during average, single -dry, and multiple -dry years. WBMWD projections consider hydrological and regulatory conditions that may affect the availability of imported water supplies.
However, as noted above, the City will evaluate the potential for a water supply shortfall based on WBMWD’s anticipated water supply conditions.
UNCONSTRAINED DEMAND
DWR guidance for the Annual Assessment considers the expected water use in the current year, based on recent water use, and before any triggered water shortage level.
Generally, expected customer demands will be estimated per the methodologies and assumptions described in the City’s UWMP unless more current data or improved methodologies are available. The data for the unconstrained water will be estimated based on the demands of the most recent Fiscal Year with unconstrained demands.
Influenced factors such as weather, growth, supply management policies, and other factors will also be considered.
DEMAND ESTIMATES
Currently, the City is 87 percent reliant on imported water supplies from WBMWD; therefore, infrastructure considerations within the City's system focus on the available water supply distribution. According to the City's 2021 Risk and Resilience Assessment, the City was generally resilient in compliance with the 2018 America's Water Infrastructure Act (AWIA).
Capital improvement projects are either underway or planned for maintenance and/or improved system reliability; however, infrastructure -related constraints on supplying water are not an immediate concern under normal operating conditions.
To improve water supply reliability and reduce the City’s dependence on imported water supply, the City is in the process of utilizing more of its local groundwater supply starting in 2022; this capacity and reliability of that water supply are taken into consideration for the City’s Annual Assessment.
0 100
200
300
400
500
600
700
800
900
1,000
1,100
1,200
1,300
1,400
1,500
August October December February April June August October December February April June City of Manhattan Beach - Water Demand and Supply
Well Production WBMWD Supply Water Demand
Unconstraint Year - Actual
(FY 20/21)
One Dry Year
(FY 21/22)
Acre-feet
City of Manhattan Beach - AWSDA
Table 1. Annual Assessment Information
Annual Assessment Information
Year Covered By This Shortage Report (Required)
Start: July 1, 2023
End: June 30, 2024
Volume Unit for Reported Supply and Demand:
(Must use the same unit throughout) AF
Supplier's Annual Assessment Planning Cycle (Required) Start Month: July
End Month: June
Data Interval:
Water Supplier's Contact Information (Required)
Water Supplier's Name: Manhattan Beach-City, Water Dept.
Contact Name: Lourdes Vargas
Contact Title: Utilities Manager
Street Address: 3621 Bell Ave
ZIP Code: 90266
Phone Number: 310-802-5320
Email Address: [email protected]
Report Preparer's Contact Information
(if different from above)
Preparer's Organization Name:
Preparer's Contact Name:
Phone Number:
Email Address:
Supplier's Water Shortage Contingency Plan
WSCP Title Manhattan Beach Water Shortage Contingency Plan (amended 6-21-22) WSCP Adoption Date 11/2/2021
Other Annual Assessment Related Activities
Activity Timeline/ Outcomes / Links / Notes
Annual Assessment/ Shortage Report Title: Optional
Annual Assessment / Shortage Report Approval Date: MM/DD/YYYY Other Annual Assessment Related Activities: Optional
(Add rows as needed)
= From prior tables
= Auto calculated
Use Type Start Year: 2023 Volumetric Unit Used 2: AF
Jul Aug Sep Oct Nov De c Jan Feb Mar Apr May Jun Total by Water Demand Type
Single Family 374.30 224.20 348.30 213.10 332. 80 191.30 273.70 181.50 270.00 180.50 261.50 201.70 3052.9 Multi-Family 27.30 35.10 21.90 32.40 24. 80 31.10 22.40 29.70 24.30 28.50 24.80 31.40 333.7 Commercial 74.20 36.10 65.80 36.40 65. 40 28.40 60.50 28.70 64.00 28.20 69.30 33.30 590.3 Industrial 45.30 0.00 44.70 0.00 45. 00 0.00 35.80 0.00 3.80 0.00 45.60 0.00 220.2 Landscape 31.00 8.70 29.70 10.40 23. 40 7.20 10.50 5.30 16.60 5.90 20.60 8.00 177.3 0 0
0 0
0 552.1 304.1 510.4 292.3 491.4 258 402. 9 245.2 378.7 243.1 421.8 274.4 4374.4 All Demands 67.20 0.00 62.20 0.00 37. 10 0.00 21.90 0.00 35.80 0.00 45.20 0.00 269.4 0 0
0 0
67.2 0 62.2 0 37.1 0 21. 9 0 35.8 0 45.2 0 269.4
Jul Aug Sep Oct Nov De c Jan Feb Mar Apr May Jun Total
552 304 510 292 491 258 403 245 379 243 422 274 4, 374
552 320 553 320 522 285 483 264 408 265 487 299 4,758
477 303 558 326 566 276 391 261 406 247 459 296 4,567
496 307 565 297 529 307 447 259 372 254 486 295 4,614
Table 2: Water Demands1
Projected Water Demands - Volume3
Total by Month (Non-Potable)
1Projections are based on best available data at time of submitting the report and actual demand volumes could be different due to many factors. 2Units of measure (AF, CCF, MG) must remain consistent. 3When opting to provide other than monthly volumes (bi-monthly, quarterly, or annual), please see directions on entering data for Projected Water Demand in the Table Instructions.
Notes: List considered factors impacting demands
Total by Month (Potable)
Additional
Description
(as needed)
Level of
Treatment
for Non-
Potable
Supplies
D
rop-down
list
Drop-down list
May select each use multiple times
These are the only Use Types that
will be recognized by the WUEdata
online submittal tool
(
Add additional rows as needed)
Demands Served by Potable Supplies
Demands Served by Non-Potable Supplies
Three years ago total demand
Four years ago total demand
Optional (for comparison purposes)
Last year's total demand
Two years ago total demand
City of Manhattan Beach - AWSDA
= From prior tables
= Auto calculated
Water Supply Start Year: 2023 Volumetric Unit Used 2: AF Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun
Total by
Water
Supply Type
Purchased/Imported Water 441.80 435.70 407.50 394.80 366.00 333.90 335.70 318.20 337.70 344.30 369 359.8 4444.4 Groundwater (not desal.) 12.2 19.1 17.1 14.9 13.1 3 11.7 20.7 51.1 37 35.3 35.3 270.5 0 0
0 0
0 0
0 0
454 454.8 424.6 409.7 379.1 336.9 347.4 338.9 388.8 381.3 404.3 395.1 4714.9 0 Recycled Water 67.19 0 62.24 0 37.05 0 22.15 0 35.61 0 45.23 0 269.47 0 0
0 0
67.19 0 62.24 0 37.05 0 22.15 0 35.61 0 45.23 0 269.47 0 Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Total
454 455 425 410 379 337 347 339 389 381 404 395 4,715
Table 3: Water Supplies1
Projected Water Supplies - Volume3
Water
Quality
Drop-down
List
Total Right
or Safe
Yield*
(optional)
Additional
Detail on
Water
Supply
Drop-down List
May use each category multiple
times.These are the only water
supply categories that will be
recognized by the WUEdata
online submittal tool
(Add additional rows as needed)
Potable Supplies
Non-Potable Supplies
eAR Reported Total Water Supplies
Optional (for comparison purposes)
1Projections are based on best available data at time of submitting the report and actual supply volumes could be different due to many factors. 2Units of measure (AF, CCF, MG) must remain consistent. 3When opting to provide other than monthly volumes (bi-monthly, quarterly, or annual), please see directions on entering data for Projected Water Supplies in the Table Instructions.
Notes: List hydrological and regulatory conditions, infrastructure capabilities, and plausible constraints which may impact the water supplies Total by Month (Potable)
Total by Month (Non-Potable)
City of Manhattan Beach - AWSDA
= Auto calculated
= For manual input
Table 4(P): Potable Water Shortage Assessment 1 Start Year: 2023 Volumetric Unit Used 2: AF Jul Aug Sep Oct Nov De c Jan Feb Mar Apr May Jun3 Total Anticipated Unconstrained Demand 552.1 304.1 510.4 292.3 491. 4 258.0 402.9 245.2 378.7 243.1 421.8 274.4 4374.40 Anticipated Total Water Supply 454.0 454.8 424.6 409.7 379.1 336.9 347.4 338.9 388.8 381.3 404.3 395.1 4714.90 Surplus/Shortage w/o WSCP Action -98.1 150.7 -85.8 117.4 -112.3 78.9 -55.5 93.7 10.1 138.2 -17.5 120.7 340.5 % Surplus/Shortage w/o WSCP Action -18% 50% -17% 40% -23% 31% -14% 38% 3% 57% -4% 44% 8% State Standard Shortage Level 2 0 2 0 3 0 2 0 0 0 1 0 0 Benefit from WSCP: Supply Augmentation 0.0
Benefit from WSCP: Demand Reduction 82.8 45.6 76.6 43.8 73. 7 38.7 60.4 36.8 56.8 36.5 63.3 41.2 656.2 Revised Surplus/Shortage with WSCP -15.3 196.3 -9.2 161.2 - 38.6 117.6 4.9 130.5 66.9 174.7 45.8 161.9 996.7 % Revised Surplus/Shortage with WSCP -3% 65% -2% 55% - 8% 46% 1% 53% 18% 72% 11% 59% 23% = Auto calculated
= For manual input
Table 4(NP): Non-Potable Water Shortage Assessment 1 Start Year: 2023 Volumetric Unit Used 2: AF Jul Aug Sep Oct Nov De c Jan Feb Mar Apr May Jun3 Total Anticipated Unconstrained Demand: Non-Potable 67.2 0.0 62.2 0.0 37. 1 0.0 21.9 0.0 35.8 0.0 45.2 0.0 269.40 Anticipated Total Water Supply: Non-Potable 67.2 0.0 62.2 0.0 37.1 0.0 22.2 0.0 35.6 0.0 45.2 0.0 269.5 Surplus/Shortage w/o WSCP Action: Non-Potable 0.0 0.0 0.0 0.0 -0.1 0.0 0.3 0.0 -0.2 0.0 0.0 0.0 0.1 % Surplus/Shortage w/o WSCP Action: Non-Potable 0% 0% 0% 1% -1% 0% 0% Benefit from WSCP: Supply Augmentation 0.0 0.0 0.0 0.0 0. 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Benefit from WSCP: Demand Reduction 0.0 0.0 0.0 0.0 0. 0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 Revised Surplus/Shortage with WSCP 0.0 0.0 0.0 0.0 - 0.1 0.0 0.3 0.0 -0.2 0.0 0.0 0.0 0.1 % Revised Surplus/Shortage with WSCP 0% 0% 0% 1% - 1% 0% 0% 1Assessments are based on best available data at time of submitting the report and actual volumes could be different due to many factors. 2Units of measure (AF, CCF, MG) must remain consistent. 3When optional monthly volumes aren't provided, verify Tables 2 and 3 use the same columns for data entry and are reflected properly in Table 4 and make sure to use those same columns to enter the benefits from Planned WSCP Actions. Please see directions on the shortage balancing exercise in the Table Instructions. If a shortage is projected, the supplier is highly recommended to perform a monthly analysis to more accurately identify the time of shortage. 4If you enter any WSCP Benefits, then you must enter the corresponding planned Actions into Table 5. = From prior tables
Planned WSCP Actions4
1Assessments are based on best available data at time of submitting the report and actual volumes could be different due to many factors. 2Units of measure (AF, CCF, MG) must remain consistent. 3When optional monthly volumes aren't provided, verify Tables 2 and 3 use the same columns for data entry and are reflected properly in Table 4 and make sure to use those same columns to enter the benefits from Planned WSCP Actions. Please see directions on the shortage balancing exercise in the Table Instructions. If a shortage is projected, the supplier is highly recommended to perform a monthly analysis to more accurately identify the time of shortage. 4If you enter any WSCP Benefits, then you must enter the corresponding planned Actions into Table 5. = From prior tables
Planned WSCP Actions4
City of Manhattan Beach - AWSDA
July 1, 2023 to June 30, 2024
Enter Amount
(Drop-down
List)
Select % or
V
olume Unit
Start Month End Month
0 (No Shortage) Landscape - Limit landscape irrigation to specific days Yes July June
0 (No Shortage) Landscape - Limit landscape irrigation
to specific times Yes July June
NOTES:
Notes Section to be used
only for clarifying details,
a
nd not for listing specific
actions. Actions must be
entred into table rows
1If you plan Supply Augmentation Actions then you must enter WSCP Benefits from Supply Augmentation Actions into Table 4. If you plan Demand Reduction Actions then you must enter WSCP Benefits from Demand Reduction Actions into Table 4. 2If an Action is planned to be implemented in multiple non-contiguous periods of the year, please make separate entries on multiple rows for the same action spanning the different implementation periods.
Table 5: Planned Water Shortage Response Actions
Add additional rows as needed
How much is action going to
reduce the shortage gap?
(Optional)
When is shortage response
action anticipated to be
implemented2?Is action
already being
implemented?
(Y
/N)
ACTIONS1: Demand Reduction,
Supply Augmentation, and Other
Actions.
(Drop-down List)
These are the only categories that will
be accepted by the WUEdata online
submittal tool. Select those that apply.
Anticipated Shortage
Level
Drop-down List of
S
tate Standard Levels (1 -
6) a
nd Level 0 (No
Shortage)
City of Manhattan Beach - AWSDA