The Villa Park Dam forms a flood control reservoir to control spills from Irvine Lake and flood control for the cities of Villa Park, Orange, Tustin and Santa Ana. The VP Dam also regulates the water inflow of Santiago Creek into the Santa Ana River. Below Villa Park Dam, is Santiago Creek which is confined to a flood control channel for the remaining 7 miles (11 km) of its course. Due to flood control requirements, the Villa Park reservoir is typically at a very low level or empty during the dry season. The Villa Park Reservoir is at an elevation of 581 feet with a maximum capacity of 15,600 acre feet.
The Villa Park Dam is an embankment dam on Santiago Creek providing flood control for Villa Park, Orange, Tustin and Santa Ana. The creek only flows during heavy storms and the dam’s reservoir is typically at a very low level or even empty during the dry season. The reservoir, with a maximum capacity of 15,600-acre feet, also controls spills from Irvine Lake and regulates the inflow of Santiago Creek into the Santa Ana River.
Discharge from the dam is captured by recharge basins downstream such as Santiago Creek Recharge Basin located in between Villa Park Road at the border of Orange and Villa Park.
Construction of the dam was completed in 1963, and the dam is owned by the County of Orange and operated by OC Public Works. The Villa Park Dam is located (8048 E Lolita St, Orange, CA 92869) near Santiago Oaks Regional Park in the City of Orange and 2.8 miles from Villa Park.
OC Public Works
OC Public Works (OCPW) maintains Villa Park Dam plus four other dams and seven pump stations located throughout Orange County.
The Villa Park Dam is the District’s largest dam in its inventory of dams for flood control purposes. It is classified by California’s Department of Safety of Dams (“DSOD”) as an “extreme[ly] high” hazard facility due to the population (greater than 1,000) within the dam inundation area.
For questions about the dam or reservoir call OCPW at 714-955-0200.
There is also a Rainfall Station at the Villa Park Dam.
What’s that Smell?
OC Public Works releases water from time to time that will flow from the dam and follow the Santiago Creek through Santiago Oaks Regional Park. The release of water from Villa Park Dam can cause a sulfur-like odor in the surrounding area which is a fancy way of saying it smells like rotten eggs. In the past the smell was bad enough that OC Public Works to halted the release early. Authorities have said it is from decomposing leaves and other debris.
Villa Park Dam History
The Villa Park Dam was approved to be built in 1936 however it took over two decades before funding for the dam was received through a 1956 bond election and completed in 1963.
Flood of 1969
In February of 1969 there were massive rainstorms and floods that created one of the worst natural disasters in Orange County history. The most damage occurred due to a mudslide in Silverado Canyon resulting in 5 deaths and 17 injured. However, the cities of Orange and Santa Ana also experienced damaging floods due to both Santiago and Villa Park dams being filled to capacity as runoff volumes exceeded design estimates for the theoretical 100 year storm. Many highway bridges and commercial and residential properties sustained severe damages.
The ’69 flood forced officials, builders and the Army Corps of Engineers to authorize the Santa Ana River Mainstream project which resulted in the Prado Dam, the Bond Street groundwater replenishment to increase flood storage, outlet gates at Prospect street for storm runoff and made the river channel through 30 miles of Orange County concrete.
In 1999 the Seven Oaks Dam was completed which captures floodwaters before it enters the Inland Empire and can withstand a 350-year flood. The Dam is also designed to resist an earthquake measuring 8.0 on the Richter scale.
Villa Park Dam House
Also built in 1963, there is a single-family residence located above the dam which previously served as the former dam keeper’s home. The home is very private and features scenic views of the foothills and Santiago Creek. The home includes a two-car attached garage, fireplace, and a backyard enclosed by a chain link fence.
California Department of Water Resources Division of Safety of Dams Information
State Dam Number: 1012
National ID Number: A00829
Owner: County of Orange
Dam Height: 118 feet
Crest Length: 119 feet
Reservoir Capacity: 15,600 acre-feet
Dam Type: Earthen Embankment
Certified Status: Certified
Downstream Hazard: Extremely High
Condition Assessment: Satisfactory
Reservoir Restrictions: No
Year Built: 1963
Type of Spillway: Concrete oggee weir and side channel
See glossary below for additional description of each item.
Villa Park Dam Additional Information
Designed By: Local firm of Harrison & Woolley
Drainage Area: 83.4 square miles
Reservoir Area: 480 acres
Design Outflow (100-yr): 3,500 cfs
Downstream Discharge at Chapman Ave. : 3,900 cfs
Discharge into Santa Ana River: 5,000 cfs
Villa Park Dam Glossary
Via the State of California California Natural Resources Agency Department of Water Resources Division of Safety of Dams
Dam Height – Vertical distance from the downstream toe of the dam to the dam crest (measured in feet).
Crest Length – Distance measured along the dam crest from one abutment to the other (measured in feet).
Reservoir Capacity – Maximum amount of water that the dam can impound (measured in acre-feet).
Certified – Jurisdictional sized dams that may safely impound water to the elevation specified on the Certificate of Approval.
Downstream Hazard – Loss of Human life is considerable; Economic, Environmental and Lifeline losses – Yes, major impacts to critical infrastructure or property
Condition Assessment – No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the applicable regulatory criteria or tolerable risk guidelines
State Dam Number – Unique identification number used for inventorying dams in California based on the jurisdictional status of a dam. This number is assigned and used by the Division of Safety of Dams (DSOD).
National Inventory of Dams Identification Number (National ID No.) – Unique identification number used for inventorying dams in the U.S. Army Corp of Engineers’ National Inventory of Dams (NID) database. DSOD is responsible for assigning this number for dams in California
More Dam Information
Embankment Dams – Massive dams made of earth or rock. Embankment dams usually have some sort of waterproof interior (called the core), which is covered with earth or rock fill. Grass may even be grown on the earth fill. Water will seep in through the earth or rock fill, but should not seep into the core. They rely on the weight to resist the flow of water, just like concrete gravity dams. The embankment dam is the only dam type that is not made of concrete.