Reports - Engineering
2020 State of the Basin Report

West Yost, Watermaster's engineering consultant, produces the State of the Basin Report every two years reporting on the current health of the Basin and the status of Optimum Basin Management Program. For the latest report, click the button immediately below. See gray section below for a complete listing of published reports.

2020 State of the Basin Report


OBMP Staff Status Report 2021-2

Every six months, Watermaster produces the OBMP Semi-Annual Status Report. This twice a year report summarizes the progress of the OBMP implementation during the previous six months. For the latest report, click the button immediately below. See gray section below for a complete listing of published reports.

OBMP Staff Status Report 2021-2


2020/21 Annual Report of the Ground-Level Monitoring Committee

Formerly known as the Land Subsidence Committee, the Ground-Level Monitoring Committee produce a report annually summarizing the activity that occurred throughout the preceeding year. For the latest report from this committee, click the button immediately below. See gray section below for a complete listing of published reports.

2020/21 Annual Report of the Ground-Level Monitoring Committee


Annual Report of the Prado Basin Habitat Sustainability Committee, Water Year 2020

The Prado Basin is a flood control area in the southern portion of the Chino Basin. Since the construction of the Prado Dam in 1941, a riparian habitat had developed in this region including species with protected statuses. The Prado Basin Habitat Sustainability Committee was formed to help protect the riparian habitat. For the latest report from this committee, click the button below. See gray section below for a complete listing of published reports.

Annual Report of the Prado Basin Habitat Sustainability Committee, Water Year 2020


Routinely Published Reports
OBMP State of the Basin Reports
Available Reports
OBMP Semi-Annual Status Reports
Available Reports
Ground Level Monitoring Committee
Available Reports and Related Documents
Prado Basin Habitat Sustainability Committee
Available Reports
Maximum Benefit/Hydraulic Control
Available Reports and Related Documents
Streamflow Monitoring Reports
Available Reports

Other Reports and Documents

The Chino Basin Judgment defines the Safe Yield as the “long-term average annual quantity of ground water (excluding replenishment or stored water but including return flow to the Basin from use of replenishment or stored water) which can be produced from the Basin under cultural conditions of a particular year without causing an undesirable result.”

The Optimum Basin Management Program (OBMP) was developed in a collaborative public process that identified the needs and wants of all stakeholders, described the physical state of the groundwater basin,defined a set of management goals, characterized impediments to those goals, and developed a series of actions that could be taken to remove the impediments and achieve the management goals.

The 2007 ground water model and its 2013 model update, collectively referred to as the Chino Valley Model (CVM), were prepared for the evaluation of the Peace II Project and the Safe Yield Recalculation respectively. Please see Resolution 2020-05 of the Chino Basin Watermaster Regarding Procedure and Fee Schedule for Requesting Information and Documents Related to the CVM.

The Recharge Master Plan is a basin-wide effort led by the Inland Empire Utilities Agency, Watermaster, the Chino Basin Water Conservation District, and the San Bernardino County Flood Control District to achieve: 1) Enhance Basin Water Supplies; and 2) Protect and Enhance Water Quality.

Monthly recharge activities based on IEUA's reporting of Groundwater Recharge may be found here.