It was recently reported that Okanagan Lake water level was not lowered sooner due to the decision to protect fish stocks (Global News, June 9, 2017). Unfortunately this position is out of context and missing key information, particularly in regards to the use of the Fish Water Management Tool in current Okanagan water management.
Fish Water Management Tool FAQ
1. What is the Fish Water Management Tool (FWMT)?
The FWMT is an internet-accessible, multi-user, modelling software designed specifically for the Okanagan basin. The software provides in-depth information and models for making weekly water releases from Okanagan dam that account for flood, drought (irrigation concerns), protection of sockeye eggs in the river and kokanee eggs in the lake. Okanagan Lake and Okanagan River levels are taken in to consideration, but not any of the tributaries. A FWMT Steering Committee meet to discuss Okanagan Lake and Okanagan River flows. Members of committee include the Okanagan Nation Alliance (ONA), Department of Fisheries and Oceans (DFO), and Ministry of Forest, Lands, and Natural Resource Operations (FLNRO).
2. How are water-flow decisions made in the Okanagan?
Managing flow is extremely complex; there is no way to predict the sudden changes in precipitation and flows. The Water Manager in the region is FLNRO. FLNRO is also a member of FWMT committee. Typically, decisions on lake and river levels are discussed collaboratively, however the FWMT group has no jurisdiction over FLNRO water management. FLNRO makes the final decision but have been understanding of fish needs. FLNRO Water Managers are diligent about flows and lake levels, so much that the lakes and river level have been consistent over the years. This may be part of the current problem – it creates expectations that water levels vary only in feet whereas it is normal to vary in meters.
3. Why was 2017 challenging in predicting spring water flows?
March, 2017, snow packs were 86% of normal in the Okanagan. The FWMT model relies heavily on this snow pack data to model spring runoff levels. Thus the planning and modelling from January to April was for a drought. The Okanagan River flows were higher than normal over winter which did draw down the lake water levels, but still the thoughts were to be conservative in case the weather tipped toward a drought scenario as forecasts were for hot dry summer this year.
Since mid-April, precipitation exceeded predictions, and with lower than normal temperatures snow accumulation continued (being measured at 140% of normal), rapidly doubling the projected in-flows. The discussion at the FWMT committee was that water management planning was now around flood, which means to increase river flows to draw down the lake to make room for tributary flows.
4. What was the process for decision making?
In April, FLNRO Water Managers, as part of the FWMT committee, discussed the potential flood concerns. At this time Water Managers were planning on increasing river flows. ONA and Osoyoos Indian Band (OIB) field crews collected the data needed to ensure that the fish were emerged and safe. Flows were raised shortly after, but the rains continued and flooding was the result in Okanagan Lake and many of the tributaries. Allowing time to confirm fish emergence did not cause the current flooding in Okanagan Lake, it was the result of the unpredictable perception at the time.
For further information please contact:
Howie Wright, ONA Fisheries Manager / HWright@syilx.org / 1-250-707-0095 ext. 104