Introduction to Performance Measures

GES 400H

UMBC Fall 2010

Megan Wiley Rivera

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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

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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

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Multiple PMs are needed

• Water resources problems are multi-objective• Some possible areas

– Water supply reliability

– Water quality

– Recreation

– Power generation

– Navigation

– Environmental Measures

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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

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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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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

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0.5

1

1.5

2

time

base run plan run

Wading Bird Value

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Performance Measure Revised

0

2

4

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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