January 29, 2013
Lake Diefenbaker
Reservoir Operation
Proposed Operating Manual
Development
Outline
• Background
• About Lake Diefenbaker
• Typical Operations
• 2010/11 Operations
• University of Saskatchewan Review of 2010/11 Operations
• 2012 Stakeholder Engagement
• Reservoir Operations Manual Template
• Proposed Process for Lake Diefenbaker ROM
Background
• WSA responsible for operation and maintenance of 45 dams,
control structures and/or weirs.
• Provincial 25 Year Saskatchewan Water Security Plan calls for
review and update of reservoir operating plans (now operating
manuals) on a priority basis
• Government has committed to completing ROM for Lake
Diefenbaker be early 2014.
Lake Diefenbaker Specifications
Reservoir Design Full
Supply Level (FSL)
Effective drainage area
556.87 metres
Maximum depth
58 metres at FSL
Length
225 km at FSL
Area
43,000 hectares at FSL
Storage at FSL
9,400,000 dam3 (total)
4,300,000 dam3 (live)
126,000 km2
Operation Targets for Lake Diefenbaker
558
Full Supply Level = 556.87 m
557
556
Maximum
(5)
555
Daily Mean
554
553
(4)
552
(3)
551
(2)
550
(1)
Target Elevations
549
548
(1)
(2)
(3)
(4)
(5)
Minimum
Minim um
547
West Side Pumping Plant
Grainland W.U.A.
Miry Creek W.U.A.
Elbow Harbour
July 1 Piping Plover Target
546
549.86 m
550.47 m
551.41 m
552.00 m
555.00 to
555.30 m
545
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
2500
557
Diefenbaker Lake 2010 to 2011
556
(Inflow, Outflow, Elevation)
555
2000
554
1st 2011 Alta
Rain Event
553
Well Above
Upper Quartile
Summer Inflow
1500
552
2nd,3rd
Alta Rain
551
550
Inflow
Outflow
Well Above
Upper Quartile
Prairie Inflow
Upper Quartile Inflow
1000
Elevation
549
548
Median Elev
547
546
500
545
2 Units Full
1
2
3
1,2,3 Three reductions for S'toon Pipeline
0
Started Spill
May 2, 2011
Reduced Outflow to Avoid
Spilling on SaskRiver Hydro
544
543
542
Diefenbaker Lake Levels
557
556
Elevation - m
555
554
553
552
551
550
549
Recorded
Lower Quartile
Median
Upper Quartile
3500
558
557
556
555
554
553
552
551
550
549
548
547
546
545
544
Discharge - m3/s
3000
1:10 year
Peak Inflow
2500
2000
1500
1000
500
0
Apr 1, 2011 May 1, 2011
Inflow
Jun 1, 2011
Outflow
Jul 1, 2011
Aug 1, 2011
Elevation
FSL
Elevation - m
Diefenbaker Flows and Levels
U of S Review of 2010/11 Lake
Diefenbaker Operations
• Reviewed flow and operational records, data records, interviewed
staff and external experts
• Final report delivered February 2012
• 8 major recommendations
• First identifies the need for a document clearly outlining the
priorities and rules for operating the reservoir over the range of
expected flow conditions
• Second identifies the need to clarify the operating objectives.
• Remaining deal with data, modeling, and understanding of river
ice.
2012 Stakeholder Engagement
• WSA recognized need for stakeholder input in fall 2011
• Independent consultant retained to conduct an engagement
process starting in late May 2012.
• Separate meetings for each sector (d/s municipal,
environment, First Nations, government, industry, u/s
municipal, recreation, metis)
• Explored values and priorities
• Report provided to WSA in December 2012.
• Posted on website https://www.wsask.ca/Lakes-andRivers/Dams-and-Reservoirs/Developing-and-Operating-Planfor-Lake-Diefenbaker/
ROM Template
• Intended primarily for use by Forecasting & Operations
• Provides clarity, consistency, defensibility, multiple forecasters
• Intended to fit into OM&S manuals required by CDA guidelines
• Applies to current realities
• Seven sections plus Appendices
1. Introduction and background
2. Objectives (purposes and priorities)
3. Constraints (dam safety, physical, legal)
4. Operating Zones and Rule Curves
5. Operating Plans
6. Protocol to determine operating recommendation
7. Procedure to execute decision
ROM Template
5. Operating Plans (flow conditions terminology from CDA)
Routine
Below normal flow (not all users satisfied)
Normal flow (all or most users satisfied)
Moderate floods (not all users satisfied)
Unusual
Large floods (multiple users not satisfied)
Emergency
Situation in which the dam is potentially threatened
Refers to Emergency Response Plan if available
ROM Template
6. Protocol to determine Operating Recommendation
•
•
•
•
•
•
For use by Forecasters
What meteorologic stations, hydrometric stations
What hydrologic and routing models, where they are
May include flow charts and check lists
What documentation is required and where it is to be
filed
May refer to Products and Procedures Manual (under
development)
ROM Template
7. Procedure to execute decision
•
•
•
•
Procedure to move from recommendations to
implementation…decision chain
Communication of decision externally – Who, how and
when notification of decision is provided to reservoir
users and downstream stakeholders
May include flow charts and check lists
What documentation is required and where it is to be
filed
Process for Lake Diefenbaker ROM
• Revise existing into new ROM format
• Develop suite of alternative Operating Plans
• 2010/11 Review
• Stakeholder Engagement report
• Internal consultation and buy-in
• Develop reservoir performance measures
• Assessment of alternative Operating Plans
• WRM modeling for water supply and seasonal and interannual variability
• Flood routing assessment, reservoir peak levels and
duration, downstream flows and levels
• Simple economic assessment
Process for Lake Diefenbaker ROM
• Selection of preferred alternative
• Compile assessment results
• Internal review and selection
• Finalize documentation of assessments and process
• Preferred draft ROM and supporting documentation available
for government approval
Questions?