The North Salt Spring Waterworks District went to referendum March 28, 2015, asking for ratepayer approval of amended Borrowing By-law 264 which allows the District to secure the funds necessary to build a new water treatment plant on St. Mary Lake. The referendum was successful and the District is now moving forward on construction of the St. Mary DAF water treatment facility which is expected to be complete in late 2016.
In 2008, Island Health amended the District’s operating permit requiring the construction of a Dissolved Air Floatation (DAF) Water Treatment Plant to meet Island Health’s 4-3-2-1 Policy for the treatment of surface water.
In response, the Board of Trustees engaged Kerr Wood Leidal (KWL) Consulting Engineers, a firm with extensive experience in the design and construction of waterworks infrastructure, to prepare the design. The Preliminary Design and cost estimate were completed last year, and KWL’s work on the Detailed Design is expected to be complete by the middle of February. It will include the final cost or Class “A” estimate which will be made public once Ministry approval has been received. In addition, once the qualified bidders have been selected, the District hopes to realize further cost saving through the competitive bid process. The revised preliminary costs are currently available on our website’s Preliminary Design page.
As can be expected, during the ongoing design process, a number of ideas were proposed, considered and either adopted or discarded as we endeavour to provide improved water quality and maximum value to our ratepayers. Many factors needed to be taken into consideration for the final design in order for the District to build a plant that meets our long-term needs for both supply and operation, while also meeting stringent regulatory requirements. As the District already operates two DAF plants for the CRD, operator input has been key in designing a facility that will ensure cost-effective operation in all potential circumstances. The aesthetics of the plant and site have also been a major consideration as the lakeshore is lined with both private residences and resort accommodation.
Design Changes Have Equalled Cost Savings
A number of design changes, that have resulted in cost savings, have been made since the initial Preliminary Design was first released. Most importantly, plant design capacity has been capped at 4.5ML or 0.943 million imperial gallons per day. This is the result of other concurrent and ongoing work on the hydrology of St. Mary Lake which suggests that no further withdrawal licenses will be available from St. Mary. The current license allows a maximum daily withdrawal of 943,500 imperial gallons, provided that the Duck Creek weir is raised to 41.0 m elevation GSC, the lake’s historical high water mark. Withdrawal of the District’s full licenced amount appears to be within the sustainable supply limits of the lake once the weir is raised to 41.0 m. Consequently, any provisions necessary to accommodate further expansion have been eliminated from the design. This includes the elimination of one intake and the need to upsize the water main along Tripp Road. A minor relocation of the wet well has also made it possible to eliminate one manufactured concrete block wall in favour of using blasted rock from the site excavation.
A portion of the District’s reserve funds have been used to pay for the Detailed Design work, which will further reduce the amount financed. However, as the Board is concerned about changing commodity prices and rising interest rates a healthy contingency will be attached to our borrowing estimate.
To assure that the full withdrawal license is available, the District is moving ahead with the raising of the Duck Creek Weir. Anderson Civil Engineering Consultants has been instructed to complete the weir design and submit it for approvals. EcoFish Research is handling permits and environmental oversight of the construction phase of the project. Raising of the Duck Creek weir is required to supply current commitments, including minimum environmental flows as required by the Department of Fisheries and Oceans. We hope this work will be completed by summer 2016 in order to store the 2016/17 winter rains. However, even with the weir at 41.0 m elevation GSC, St. Mary will not have the capacity to support further development. It should be noted that properties within the District boundaries that do not currently have water service but have paid a capital expenditure charge and pay a parcel tax to the District, are considered current commitments, not further development, and will be eligible for water service if requested. Supplying water for further development would require raising the weir higher than 41.0 m GSC which is not feasible for a number of reasons including the proximity of homes and roads as well as the limited amount of rainfall in the lake catchment area.
Raising the weir requires consultation with the lakeshore landowners. This process is currently underway.
Conservation and Drought Management Are Key
Another result of our improved understanding of the hydrology of St. Mary Lake is an increased awareness that conservation and drought management plans are needed to ensure a sustainable supply. In the summer of 2014, the District asked for voluntary conservation and our ratepayers responded well. Despite a Stage 3 drought continuing into October, critical environmental flows in Duck Creek were maintained to protect fish habitat. Nevertheless, more conservation work is required. The District has already taken a number of the most important steps towards conservation: the distribution system is fully metered, an annual water audit is performed, infrastructure upgrades have been completed to reduce operational losses and a progressive conservation-oriented rate structure has been implemented. Before the summer of 2015, the District intends to have a water conservation by-law in place. Developing conservation and drought management plans are the next steps to achieving sustainable water management. The District plans to undertake this work in the upcoming year.
Again in 2015, watershed protection will be a primary focus at Maxwell Lake. Further fencing and signage will be installed with reminders that this is a precious island resource that must be protected. The District will be installing more environmental monitoring equipment, collecting water quality data and starting to develop a more comprehensive watershed management plan for this area. The data collected will be essential when designing the water treatment facilities for Maxwell Lake.