#1SASKATCHEWAN Agency A Water Security September 15, 2017 Presentation on Saskatchewan's Flow Forecasting and Operations Planning Global Water Futures Integrated Modelling Program for Canada Kick-Off Workshop Curtis Hallborg, P, Eng. Manager of Flow Forecasting & Operations Planning#2Flow Forecasting and Operations Planning (FFOP) • We provide: • • • General flow and water supply forecasting services for the province. More detailed forecasts for select locations. Operating directives for the WSA's major reservoirs and the Qu'Appelle System. Guidance on other systems. Forecasting Products: • Conditions at Freeze-up Report Spring Runoff Outlooks Saskatchewan River Basin 10- day Forecasts Monthly Water Supply Outlook and Conditions Report Fort Smith Fort Chipewyan Fort McMurray Cluff Lake Uranium City Stony Rapids Buffalo Narrows Near Normal Cold Lake Meadow Lake Vermilion Lloydminster Wainwright 80 Below Normal Key Lake La Ronge Waskesiu Lake Spiritwood West Bay Southend Collins Above normal precipitation prior to runoff and/or a faster than typical rate of melt will result in significantly higher runoff. Conditions can vary considerably over short distances. Projected runoff is based on sparse, variable and often conflicting snow accumulation estimates. Runoff boundaries should be considered approximate. The Pas Prince Nipawin Albert Melfort Hudson Bay Swan River North Battleford Scott Above Normal Saskatoon Kindersley Rosetown Outlook Watrous Wynyard Last Mountain Yorkton Roblin Elbow Leader Lucky Dauphin Lake Swift Moose Indian Head Medicine Current Near Jaw Regina Broadview Hab Maple Creek Normal Brandon Assiniboia Weybur Cypress HINS Park Eastend Below Val Normal Marie Estevan Coronach LEGEND POTENTIAL RUNOFF Below Normal Near Normal Above Normal Well Above Normal High Very High#3Current Tools - Saskatchewan River System • • • • • Advantage of several days travel between alpine headwaters in AB and the SK Border No snowmelt or rainfall runoff modeling. Route daily observed flows in a spreadsheet. . Simple time lag method used with some smoothing. Liaison with SaskPower on operational decisions. Use HEC-RAS models to predict changes in stage at critical locations. Alberta Environment will provide their model outputs for large events. North Saskatchewan Edmonton Battle Red Deer Calgary Bow Saskatchewan Lake Winnipeg South Saskatchewan Saskatoon Lethbridge Medicine Hat Oldman#4• • Current Tools - Prairie Runoff No rainfall runoff modelling, just snowmelt Use simple empirical/regression relationships between snow water equivalent, antecedent conditions, and runoff volume and peak flow. May look at historically observed events to ballpark rainfall runoff events. Very difficult due to basin 'memory' and spatial variation of precipitation inputs and antecedent conditions. Alberta Saskatchewan Manitoba Montana North Dakota Minnesota South Dakota Prairie Pothole Region US Fish and Wildlife Service Map Iowa#5. Biggest Challenge • Due to our generally flat post glacial landscape that is dominated by small internally drained regions, we have dynamic contributing drainage basins that are controlled by fill and spill processes. Off the shelf hydrologic models developed elsewhere in the world typically don't work in the Prairie Pothole Region. They want to treat drainage area as a fixed variable and expect a basin to have a stream. Non-contributing Areas University of Saskatchewan - Center for Hydrology Map#6Challenges from Cold Region Hydrologic Processes Snow Sublimation Blowing Snow Runoff Snowmelt Infiltration into Frozen Soils Most hydrological models omit cold region processes altogether or take an overly simplistic approach to handling them.#7Sparse Data Networks Number of climate Stations precipitation data - Prair 200 180 160 140 120 100 80 60 40 20 0 1860 1880 1900 1920 194#8Prairies is the graveyard of hydrologic models RIP SWAT RIP SSARR . RIP WATFLOOD RIP HEC-HMS • There is hope through the development of modules to better handle prairie and cold region processes. • Much of this is due to research at the U of S. over the past few decades.#9Recent Changes in Flood Event Generation Prior to the summer of 2010, most major historical flooding events in the province had been snowmelt runoff generated. • Beginning in 2010, we have experienced several large rainfall runoff generated floods: ● • • Maple Creek - June 2010 Good Spirit Lake - July 2010 Souris River - June 2011 East Central Sask. - June/July 2014 Arborfield - July 2016 Permanent shift in our hydroclimate???#10Why Do we Need to Worry About Rainfall Runoff? • Increase in multi-day rainfall events and more rainfall runoff. Hydrological regime changes in a Canadian Prairie basin Stacey Dumanski, John W. Pomeroy* and Cherie J. Westbrook Centre for Hydrology, University of Saskatchewan, 117 Science Place, Saskatoon, Saskatchewan, S7N 5C8, Canada Count 40- 60000 30 50 20 10- 1940 196C Volume (dam³) 40000 20000- 0- H T 1980 1990 2000 2010 Mechanism Rain-on-Snow Rainfall Snowmelt#11What is the Province Doing? action area 5.1 flood damage prevention and emergency response in developed areas actions a. Develop improved flood forecasting tools (2016) Step One • New funding to flood forecasting in the 2014 Provincial Budget to improve flood forecasting functions, enabling the creation of a dedicated flood forecasting unit Step Two . Seeking expert advice SASKATCHEWAN Water Security Agency 25 YEAR Saskatchewan Water Security Plan#12University of Saskatchewan Consultation Key Points • • Most existing hydrological models do not include cold region processes. Even fewer models are able to simulate the fill and spill processes of the prairies. A physically based model is suggested rather than a statistically or conceptually based model. A separate reservoir simulation model is likely required. • A data handling platform will likely be required. Recommendations for Saskatchewan Hydrological Modelling A Report to the Saskatchewan Water Security Agency Kevin Shook and John Pomeroy Centre for Hydrology University of Saskatchewan 117 Science Place Saskatoon, Saskatchewan S7N 5C8 November 30, 2016 CENTRE FORE YDROLOGY UNIVERSITY OF SASKATCHEWAN Global Institute for Water Security#13What a Modern Flow Forecasting System at the WSA Might Look Like Near Real-time Time Series Data Management System (Aquarius) Hydrometric & Meteorological Data Gridded NWP Data (ensemble data from ECCC) Server Pre- Processing and potentially QA/QC Data Handling & Model Control Platform | CaPA Data Hydrological Channel Server for Archiving Model Routing Model Reservoir Simulation Model Forecast Products Output (hydrographs, Decisions report, etc.) Post- Processing/ Visualization#14• • Final Thoughts Stakes are High - Property, Lives, and Reputations are on the line We have a real opportunity here to build a system that is state of the art to serve the citizens of Saskatchewan well. Developing a modern system will be very challenging but possible. The system will not be perfect. "Essentially, all models are wrong, but some are useful." George Box The best time to plant a tree was 20 years ago. The second best time is now.