| Abstract/Description or Keywords |
This report has been prepared to provide the District of Invermere (District) with a response plan for dealing with droughts. The report summarizes the conditions that would indicate the potential for below normal supply in Goldie Creek; it provides a summary of the estimated runoff in Goldie Creek for normal years and for the 1 in 10 year low flow years and it also summarizes the typical water demand in the district. For the District, the principle surface water source is Goldie Creek, which is diverted into the Paddy Ryan Reservoir system (PRR) (refer to overview map, Figure 1.1). The PRR system is a series of three reservoirs: the first reservoir (Reservoir #1) is supplied by Goldie Creek after priority water licence allocations are met. Water travels from Reservoir #1 to #2 via seepage since the slide gate on the sluiceway is inoperable and from Reservoir #2 to #3 by adjusting the gate on the sluiceway through Dam #2. The intake to the District’s distribution system and the diversion works to Abel Creek are located in the south dam at Reservoir #3. The District has never indicated significant water shortages; however, in order to be proactive, considering climate change scenarios, and preparing for future population growth and infrastructure expansion, the District has begun to review its water supply requirements and uses. There was limited data available on the flows in Goldie Creek and also on the flows diverted from Goldie Creek to the Paddy Ryan Reservoirs. There was also limited demand data available to determine average water demand by the District. However, based on the available supply and demand data the analysis suggests that there is sufficient water available to meet the community’s demand during normal runoff years as well as during a 1 in 10 year low flow in Goldie Creek. The intake works consist of a concrete weir across Goldie Creek and diversion works to the District’s pipeline that included a 600mm diameter diversion pipe controlled by a manual slide gate and an intake box that has been designed to provide the licensed flows to the District’s intake plus two other water licensees. Control of the flow to the District’s reservoirs is regulated by adjusting the slide gate on Goldie Creek. Due to the limited available data the preliminary Drought Management Plan has been prepared based on local knowledge of the water supply and demand supported by regional data from active snow courses, hydrometric and climate stations as well as information from the Ministry of Environment River Forecast Centre. The decision to implement water restrictions is based on staff review of current supply and demand and is summarized below. If staff determines that the flows in Goldie Creek are below normal during the month of May, and the regional precipitation trends are below normal, then it is recommended that Stage 1 restrictions be implemented on June 1. If the supply trends and flows in Goldie Creek continue to be below normal by mid-June, then staff should recommend implementation of Stage 2 restrictions on June 15. Decisions to move to Stage 3 restrictions – no outdoor watering, would be based on flows in Goldie Creek, cumulative precipitation to July, and the level of demand. Staff should recommend to Council increased water restrictions if the determine that conditions are below normal for any combination of stream flows, reservoir levels, or regional precipitation. It is recommended that the District move towards a more proactive approach to water supply management by establishing a hydrometric station on Goldie Creek, re-establish the Invermere Climate station, and upgrade the Paddy Ryan reservoir monitoring system. Having these upgraded sources of information will assist the District in having a better understanding of the ongoing performance of the reservoirs and be able to ensure that the drought response is appropriate in low flow years. It is also recommended that the District confirm the live storage volumes in the reservoirs, repair the slide gate at Dam #1 and confirm that there is no requirement to release water to Abel Creek. |
