Water Availability Letter

Water Availability Letter


Water Availability Letter (WAL) Update

The Ventura County Board of Supervisors approved a revision to the Ventura County Waterworks Manual (VCWWM) (2nd Edition) on September 14, 2014 . The manual includes standards that apply to any facilities or system in the County that meets any one or more of the following conditions:

a. Is currently in or plans to be located within the County or County-dependent special district owned or controlled rights-of-way.

b. Serves, or plans to serve, water to any land development project which is subject to any approval issued by the County or a County-dependent special district.

c. Provides fire protection service in the Ventura County Fire Protection District (FPD).

Receipt and acceptance of the WAL by the County is a prerequisite to a purveyor issuing additional "will serve" letters. This requirement was implemented because experience has shown that, incrementally, "will serve" letters for additional services have been issued by some purveyors to add connections to existing water systems without taking into account the cumulative effect of all previous additions.


 Water Availability Requirements

Excerpt from VWWM §1.3.6 

A letter from a Water Purveyor declaring that the purveyor’s water system has the necessary water capacity available to supply the domestic and firefighting requirements for the project or service area identified in the letter. The Water Availability Letter must be signed by a member of the purveyor’s Board of Directors or General Manager and contain the following:

  1. A map of the project or service area served by the water system showing parcels served along with their Assessor Parcel Numbers (APNs).
  2. A description of the existing (or planned) system and all planned changes to the existing system that will be made to provide service to the project or service area identified in the letter.
  3. A completed Waterworks Manual Compliance Worksheet (Appendix D) for the system and each pressure zone in the system.
    1. The maximum day average demand (Q0), required domestic storage volume (V0) and number of service connections (N) may be calculated by using either the methods described in this manual or commonly accepted engineering practices.
  4. A summary of all areas not in compliance with this manual and the plan for bringing the water system into compliance with this manual.
  5. The engineering analysis prepared and stamped by a civil engineer which was used to prepare the Waterworks Manual Compliance Worksheet(s) and includes the following:
    1. Method and calculations for determining maximum day average demand (Q0) and required domestic storage volume (V0), for both existing and maximum number of service connections (N).
    2. Method and calculations for determining compliance with the peak hour demand requirements of this manual.
    3. Method and calculations for determining compliance with the system reliability requirements of this manual.
    4. Method and calculations for determining compliance with the emergency requirements in this manual.

In the case of Water Purveyors classified as Urban Water Suppliers under the Urban Water Management Planning Act, the adoption of a current Urban Water Management Plan that has been accepted by the State Department of Water Resources will satisfy the requirement for submission to and acceptance by the County of a Water Availability Letter (WAL).

More information on methods and procedures that can be used to prepare a WAL can be found in the Ventura County Waterworks Manual (VCWWM) 2nd Edition .The VCWWM establishes the minimum acceptable standards for the design and construction of additions or changes to existing water supply facilities in the unincorporated areas of Ventura County of Ventura and for the purpose of County or County-dependent special district approvals.

The Waterworks Manual Compliance Check sheet can be downloaded here.

Notice to Water Puveyors

In September 2014, notice was given to Ventura County Water Purveyors of the Water Availability Letter requirement and they have been give the opportunity to submit a WAL. A list of currently approved WALs or UWMP can be found on our Will Serve Letter Page. To obtain a copy of this notice please click here.



Inventory of Water Purveyors

For list of Water Purveyors in Ventura County, Click here.


Water Purveyor Search: Here


List of Water Purveyors

A current list (as of 09/08/2015) of UWMP Approved Water Purveyors is listed below.

Approved Urban Water Supplier Primary County Served
Antelope Valley - East Kern Water Agency Kern
California Water Service Company Westlake Ventura
California‐American Water Ventura District Ventura
Calleguas Municipal Water District Ventura
Camarillo, City of Ventura
Camrosa Water District Ventura
Casitas Municipal Water District Ventura
Castaic Lake Water Agency - Santa Clarita Water Division Los Angeles
Fillmore, City of Ventura
Golden State Water Company Ojai Ventura
Golden State Water Company Simi Valley Ventura
Oxnard,City of Ventura
Port Hueneme, City of Ventura
Port Hueneme Water Agency Ventura
San Buenaventura, City of Ventura
Santa Paula, City of Ventura
Thousand Oaks, City of Ventura
Triunfo Sanitation District / Oak Park Water Service Ventura
United Water Conservation District Ventura
Ventura County Waterworks District No. 1 - Moorpark Ventura
Ventura County Waterworks District No. 8 - Simi Valley Ventura

Water Purveyors with Water Availability Letters accepted by Ventura County Public Works Agency:
(Current as of April 30, 2018)
Water Suppliers with Accepted WALs 
Crestview Mutual Water Company
Channel Island Beach Community Service District
Garden Acres Mutual Water Company
Meiners Oaks Water District
Mutual Water Company of Vineyard Avenue Estates
Pleasant Valley Mutual Water Company
Saticoy Country Club
Sisar Mutual Water Company*
Senior Canyon Mutual Water Company  
Strickland Mutual Water Company*
Tobock Ranch Water District
Ventura County Waterworks District No.17 - Bell Canyon
Ventura County Waterworks District No. 19 - Somis
Ventura County Water Works District No. 38 - Lake Sherwood 
Ventura River Water District
Vineyard Mutual Water Company
Yerba Buena Water Company
Warring Water Service*
* WAL accepted with conditions, contact PWA Development & Inspection Services for Conditions of Acceptance. Will Serve Letters are not currently being accepted by these purveyors.