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Introduction to Performance Measures
GES 400H
UMBC Fall 2010
Megan Wiley Rivera
2
The CAN Process
1. Develop performance measures
2. Reach consensus on • the scientific data to be used in evaluating
alternatives
• scientific methods and assumptions to be used
• the nature of alternatives to consider and how to structure the evaluations
3. Create and evaluate alternatives in a collaborative setting with other stakeholders
3
What Is APerformance Measure?
• A display
• Compares alternatives for one or more management objective
• Needs only to distinguish "better" and "worse"
• Water management is multi-objective
• Multiple performance measures are required
4
Multiple PMs are needed
• Water resources problems are multi-objective• Some possible areas
– Water supply reliability
– Water quality
– Recreation
– Power generation
– Navigation
– Environmental Measures
5
Why are PMs so important• Without PMs parties tend to focus on abstract
portions of rules, e.g. the minimum flow requirement, the level of the summer pool rule curve
• With PMs parties can focus on overall outcomes• Creating PMs forces parties to think about what
they really care about and how to measure it
6
Performance Measure Notes
• HydroLogics rarely tries to commensurate performance measures– Single scores are not informative IMHO
• If it is not possible to evaluate a particular performance measure directly, we use surrogates
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Process for Developing Performance Measures
8 1997 Water Resources Management Inc.
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10
12
14
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0
20
40
60
80
100
time
lake stage
Lake Okeechobee Stage
Lake
Stage
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Scientific Rationale
• No habitat if lake stage exceeds 15 feet
• No forage if lake stage reverses by more than 6 inches
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Performance Measure First Attempt
0
0.5
1
1.5
2
time
base run plan run
Wading Bird Value
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Performance Measure Revised
0
2
4
6
8
10
12
Run
>= 3rd bad year in series
2nd Bad year in series
bad years
good years
Wading Bird Nesting(good years have no stage rev Feb-May)
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Performance Measures - Surrogates
1930
1940
1950
1960
1970
1980
1990
2000
Year
0 30 60 90 120 150 180 210 240 270 300 330 360 Julian Date
Flood Events - Before and After Dams5 days > 11,500; 5 day avg < 8,500 cfs
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Some Examples from the Apalachicola Chattahoochee Flint
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Currently no CAN process
• It’s been attempted (SVP), but the tri-state water wars go on (litigation)
• A lot of activity recently because of an ongoing drought in the region
• The US Fish and Wildlife Service put out a set of “performance measures” to assess whether or not the Army Corps’ proposed Interim Operation Plan violated the Endangered Species Act (Sept 2006 Biological Opinion, posted in course documents)
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Lowest flow each year
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Mussels Are Affected at Low Flows
• How much and at what flows is up for debate• Generally thought that they get too hot (lethal) at
flows < 5000 cfs• They are strained at somewhat higher flows:
6000, 6500, 7000—depends who you ask• Time is an issue
– they can handle x number of days, and after y number of days, it may not matter any more (ones who will die have died)
– We don’t know what x or y equal
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Number of consecutive low-flow days in the worst year
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Number of Low-Flow Days in Median Year
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Sturgeon Habitat Available during Spawning Season
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Note: Higher Flows Do Not Necessarily Mean More Habitat
Sweet spot at more important site
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Note: Higher Flows Do Not Necessarily Mean More Habitat
Sweet spot at more important site
1. Another example of counter-intuitive results—trying to get as much water as possible does not necessarily translate into better spawning habitat
2. Opportunity to write rules that target these flows during spawning season
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Other examples from hypothetical basin
• Most of these have been biological performance measures
• An aside, there is a “sister process” to CAN in which biological performance measures are created by a group of stakeholders (Savannah Process)– In at least one case, once they started modeling, found that
biological PMs never scored well; not enough water in system, too coarse to recognize small improvements
– In some recent processes, model used during development (recall that I suggested models should not even be chosen until you know what you’re evaluating)
– We will be using two sets of data as we develop our performance measures to make sure they are reasonable: historical and “current operations” model results
• What about other stakeholders?
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Number of Days of Recreation Impact during the period of record
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Frequency of Impact Days
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Number of Years with Extended Recreation Impact
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Number of Days of Recreation Impact during the period of record
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Water Supply
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Water Supply Ideas• Frequency of years that drought conservation measures
are taken (economic and political ramifications)• Compare to some measure of water supply reliability
– < 5% probability of storage falling below some threshold – System never “empties” (include margin of safety) based on
historic hydrology
• NYC group will need to talk with operators about their measures of reliability
• NYC gets about 50% of water from this source, so there is also room to play with how they utilize other sources