Menu

Water Supply in the San Gabriel Valley

WATER SUPPLY IN THE SAN GABRIEL VALLEY

The San Gabriel Valley Has Planned Ahead

The San Gabriel Valley and other regions throughout California have had several dry years in succession with lower than normal precipitation (i.e. rain, snow) to help replenish our water supplies. The past two years have been among the driest years on record, and 2014 was the hottest year on record, exacerbating local water supply concerns.

Fortunately, the San Gabriel Valley and the southern California region have a water supply system that includes a variety of sources of water (“water insurance”). Examples include groundwater replenishment, imported water, reservoirs and cyclic storage, recycled water, storm water capture, and water transfers.

Thus, despite recent developments such as record-breaking dry weather, a statewide drought declaration, relatively low levels of imported water deliveries via the State Water Project, and implementation of both voluntary and mandatory water usage restrictions, the San Gabriel Valley has water in reserve to meet local needs for the next few years, even if the drought continues.

However, it is a reality that local water supplies are lower than we would like. Another reality is individual cities, counties, the state and water companies may act to impose mandatory water-use restrictions and raise water rates/pricing to curtail water use. These are actions that the San Gabriel Valley Municipal Water District has no control over but that we encourage residents and businesses to become informed of in the towns in which their homes and businesses are located.

Water Supply FAQs

The San Gabriel Valley is a distinct watershed shaped by local mountains, rivers, streams and other geological formations. A major, natural source of water for the Valley is the San Gabriel River and streams, ponds, lakes, dams and reservoirs connected to it that are located either in the San Gabriel Mountains or the Valley, itself. Beneath the Valley is the Main San Gabriel Basin, the focal point of our Valley's water supply system. By far the largest component of local water supplies is groundwater pumping, providing more than 75% of historical local supplies.


Click on image to view detailed map
Here in Southern California and the San Gabriel Valley we live in a dry, desert region. We use more water than Mother Nature provides. Supplemental sources of water (other than pumping of local aquifers or underground wells), include surface reservoir production, recycled water, storm water capture and supplies imported through wheeling arrangements or transported via aqueduct from the State Water Project and the Colorado River. Imported water is used to fill spreading grounds which allows water to percolate or seep down to replenish groundwater (aquifers and wells).
Given the size and topography of the San Gabriel Valley, it's not surprising that groundwater levels throughout the Valley vary from location to location – it is true that different locations in the Valley have more water or more accessible water than others. And, some wells in the San Gabriel Valley are polluted or contaminated. Water rights and pumping rights are complicated – for example, Monterey Park relies on water that is pumped from wells located in Rosemead. Thus, many years ago the Main San Gabriel Basin Watermaster was created to manage and protect groundwater resources within the Main San Gabriel Groundwater Basin.
Because the San Gabriel Valley Municipal Water District and other water agencies throughout the Valley have employed sound water management practices for several decades, and because the Valley has reduced consumption by more than 15% in recent years through water conservation, for the most part, the Valley is not in immediate jeopardy of major water shortages. There have been and will continue to be instances of certain local wells running dry, but it is not a pervasive problem as of early 2015. Local experts estimate the Valley has enough water in reserve right now to meet the Valley's needs for several years even if the drought continues.

Some people believe in the adage that “we will not run out of water, but we will run out of cheap water.” To a degree, we are protected by larger regional water storage facilities and a reduction in water demand resulting from effective water conservation efforts, use restrictions and higher pricing.

For cities served by the San Gabriel Valley Municipal Water District, we have been preparing for water shortages like this, effectively providing you with "water insurance." In other words, as residents in our service area use water from local wells, we've been actively helping to refill or replenish the groundwater that supplies the wells.

Thus, our water insurance is declining – reservoir levels are lower, groundwater levels are lower and the snowpack throughout local and regional mountain ranges is lower.

Groundwater levels approaching historical lows in the San Gabriel Valley

A widely accepted measure of our local groundwater supplies is the Baldwin Park Key Well. As the diagram shows, groundwater levels have dipped considerably since 2011.


Click on image to view most recent verion of the Key Well Diagram
The Governor's Emergency Drought Declaration in 2014 called for voluntary water conservation efforts that would amount to a 20 percent reduction in water use. Across the State, we are witnessing a variety of voluntary and mandatory water use restrictions and pricing increases to respond to the drought and the decline in our water supplies. It's important for residents and businesses to follow local water decisions that may impact them closely.
Absolutely not! The Valley, the region and the state have been mired in a long-term drought and sporadic rain or snow events, while helpful, have not produced enough water to ease the drought. While additional winter storms may provide a limited boost to reservoir storage and water deliveries, due to the record dry levels of the past 2-3 years, it would need to rain and snow heavily for several years to get us back to average annual rainfall, snowfall and water supply levels, and to remove us from the present drought.
The City of Azusa draws its water primarily from San Gabriel Basin wells located in Azusa adjacent to spreading grounds which are located at the terminus of the pipeline operated by the San Gabriel Valley Municipal Water District. The City supplements this source of water with water coming from the San Gabriel River. Whenever the City's groundwater production exceeds its water rights, untreated imported water is delivered to the San Gabriel Basin via the pipeline operated by the San Gabriel Valley Municipal Water District to replace that amount of water which was produced in excess of the City's water rights. Water is treated, pumped to and stored in reservoirs located in the City, and then transported via the City's water distribution system to your tap.
Monterey Park's water comes primarily from San Gabriel Basin wells located in neighboring Rosemead. Whenever the City's groundwater production exceeds its water rights, untreated imported water is delivered to the San Gabriel Basin via the pipeline operated by the San Gabriel Valley Municipal Water District to replace that amount of water which was produced in excess of the City's water rights. Water is treated, pumped to and stored in reservoirs located in the City, and then transported via the City's water distribution system to your tap.
Sierra Madre's groundwater historically came primarily from wells in the Raymond Basin and from surface water that is transported via tunnels reaching into the San Gabriel Mountains. Presently, in early 2015, Sierra Madre is 100 percent reliant on its MWD connection due to low groundwater levels in its local wells. Water is treated, pumped to and stored in reservoirs located in the City, and then transported via the City's water distribution system to your tap.
The City of Alhambra's water supply is primarily groundwater pumped from a portion of the Main San Gabriel Basin which is referred to as the “The Alhambra Pumping Hole.” The City supplements this source of water with a direct connection to the Metropolitan Water District's pipeline. Whenever the City's groundwater production exceeds its water rights, untreated imported water is delivered to the San Gabriel Basin via the pipeline operated by the San Gabriel Valley Municipal Water District to replace that amount of water which was produced in excess of the City's water rights. Water is treated, pumped to and stored in reservoirs located in the City, and then transported via the City's water distribution system to your tap.