Ellis 4 Dam Upgrades

Q&A

• How many dams does Penticton have – and why?

  Penticton has 11 dams, six of which are active. Many of these were built in the early to mid-1900s, with upgrades conducted throughout the years. These dams ensure safe water storage for the community, providing a source of water to the City’s irrigation systems and agricultural community, as well as to the City’s Water Treatment Plant, where it is processed for residential use. The dams are also used to control the flow of water   into Ellis and Penticton Creeks,  essential for flood control during the spring freshet, and to ensure ongoing creek water supply for local fish and wildlife habitat. 

• What is the purpose of the Ellis 4 dam?

  The City’s Ellis 4 dam feeds irrigation water to the city’s agricultural areas with raw water. The Ellis Creek irrigation system provides water to over 80 agricultural properties (300+ acres) using a gravity-fed system. This provides a low-maintenance, cost-effective means of supplying non-treated or chlorinated water to end users while reducing the operational strain on the Water Treatment Plant.

  Both Ellis 4 and Ellis 2 dams collectively control the flow of water into Ellis Creek, which is a delicate balance to prevent flooding during peak freshet seasons, while ensuring enough water during the dryer months to support fish and agricultural irrigation water. 

• How much are the upgrades going to cost?

  The project is estimated to cost $10 million, of which $7.1 million is being provided by the federal and provincial governments through the Investing in Canada Infrastructure Program.  The remaining funding was allocated as part of the City’s budget planning process, as indicated in the 2024-2028 Financial & Corporate Business Plan.

• Why is this work necessary?

  The Ellis 4 Dam, built in 1930, does not meet the current provincial Dam Safety Regulations, which sets requirements and best practices for all aspects of dam design, construction, operation, maintenance, removal and decommissioning of dams.

  In the event of a major storm, under the worst-case conditions, the spillway may not safely pass the incoming flows, resulting in overtopping of the dam.

  This work will improve the resiliency of the structure and ensure safe water storage for years to come. This will involve restoring the existing dam to reduce the risk of failure due to climate change impacts, natural disasters and extreme weather events.

• What work will be conducted?

  The dam will be drained to allow for the excavation of the existing structure. Crews will install a Gabion basket-style structure, using wire mesh baskets filled with rock, designed to withstand natural disasters and extreme weather events.

• Will this work have an impact on fish?

  The City will ensure a steady supply of water is provided to Ellis Creek to protect the fish, including rainbow trout, Kokanee salmon and other wildlife, by utilizing the Ellis 2 dam while Ellis 4 dam is under construction. 

  The City has been working closely with the Ministry of Environment and Penticton Indian Band on this project and has all the relevant permits in place. Work in the creek and dam itself will take place during a designated time window to protect downstream fish habitat. 

• Where does Penticton’s water supply come from?

  Ellis 4 dam holds raw water that is not treated, used to feed Ellis Creek and the south irrigation system. The Penticton Creek dam system has a collection area of approximately 176 square kilometers, and the Ellis Creek dam system has a collection area of approximately 154 square kilometers of annual snow pack.

  Penticton’s water supply that is piped to homes for residential use is taken from two sources: Penticton Creek and Okanagan Lake. This water is first treated at the City’s Water Treatment Plant. To learn more about the water treatment process, visit penticton.ca/water.

• Will there be enough water for everyone this summer?

  The City will be monitoring the various sources of water through construction and through what is anticipated to be another drought year for the area and the Province as a whole.  It is not anticipated that users of either the irrigation system or the treated domestic system will be impacted by the project, however the City will be encouraging all residents and visitors to conserve water as usual during the summer months.  Should water supply levels decline, the City will move to the next stage of water restrictions.

• How long will construction be underway?

  Construction will take place between July and October of 2024, with the in-stream work being completed during the required fish window as set by the Ministry of Environment, to maintain the downstream fish environment.

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