PNW Climate Change - Law Seminars International robinson-dorn... · 2012-06-16 · PNW Climate Change: ... • More precipitation will fall as rain than snow. ... • Sea level rise

Speaker 23: Michael J. Robinson-Dorn of University of Washington School of Law

Law Seminars International | Washington Water Law | 6/4/07 in Seattle, WA

1

PNW Climate Change:Implications for Washington Water Law

Prof. Michael Robinson-DornUniversity of Washington School of LawDirector, Kathy & Steve Berman Law Clinic

June 5, 2007Water Law Seminar

Summary:Summary:Implications for Water ManagementImplications for Water Management

• Increased demand among competinguses requires greater tradeoffs (M&I,habitat, irrigation, water quality navigation,recreation, hydropower)

• Increased risk of winter flooding inmany basins (changes in urban flooding lessclear)

• Water systems must be managed forlonger and more extreme drawdownperiods that in the past

• Bottom line: Increased competitionfor water and increased vulnerabilityto drought



2

A Top 1O?• More precipitation will fall as rain than snow. (esp. important in the

lower and mid-level elevations where more winter rain and fasterand earlier snowmelt)

• Peak river flows may increase in winter and early spring• Less water available when demand is highest• Water temperatures will increase (with potential impacts to

salmonids and other fish)• Potential impacts on groundwater with lower groundwater tables

(snowpack recharge)• Increased flooding and stormwater runoff flows (with increase

pollutant loads in the high flows);• Decreased flows in the summer (with potential to decrease capacity

to assimilate pollutants) 303(d) listings under the CWA for impairedstreams—esp. temp. and DO

• Sea level rise (with potential for increased saltwater intrusion).• Increased wildfires (including damage to high elevation streams and

other favorable conditions of flow); Increased growth of somespecies in forests together with increased potential for pests—e.g.pine beetle

• Increased capacity for hydroelectric in winter (but deceaseddemand) and decreased capacity for hydroelectric in the summer(but increased demand)

The Connection to Water Law: A Top 10?The Connection to Water Law: A Top 10?

Beneficial use Waste

Federal Reserved Rights—Including

Indian Reserved Rights

InstreamFlows

New Sources

BOR

International River

Columbia River Treaty

??

Then Add to the MixThen Add to the Mix



3

• Most glaciers in the PNW are receding (melting) which has the potential toimpact base flows in some systems. E.g., Olympic and North Cascades.

Glacier Melt and DisequilibriumGlacier Melt and Disequilibrium

• Warmer temperatures willresult in more precipitationfalling as rain rather thansnow

• Snow pack will diminish,and stream flow timing willbe altered

• Peak river flows will likelyincrease

• Water temperatures willcontinue to rise

Impacts Impacts



4

Earlypeakflows

Floods

??

Warm, lowstreamflow



5

Water for Fish

• Flow augmentation from cool/cold water storage reservoirs. If this strategyrequires addition storage capacity, careful consideration of the benefits andnegative impacts of increasing the number of dams in the basin will berequired.

• Use of removable surface weirs to reduce the time juvenile salmonidsspend in the warm water of the dam forebays

• Reduce water temperatures in the ladders with water drawn from lower,cooler strata in the water column of the dam forebays

• Open backwater, slough, and other off-channel habitats along mainstemreservoirs and the estuary to encourage increased flow through these helpreduce water temperature and provide cool-water refugia

Water for FishWater for Fish

Reserved Rights

Indian Reserved Water Rights

Instream Flows?

Other Federal Reserved Rights?

Reserved RightsReserved Rights



6

Pressures and Opportunities

Beneficial Use

Economic EfficiencyAction Forcing

WasteScientific and TechnologicalAdvances

Reuse, Recycle, Reclaim

Pressures and Opportunities

• ESA listings• 303(d) designations• Population and Urbanization increases• Sea level

• Water Banks (loans transfers)• Demand Control• Efficiency and Conservation• Alternate Supplies

• Value?

Pressures, Opportunities and ExpectationsPressures, Opportunities and Expectations



7

20th Century Climate “2040s” (+3°F) “2060s” (+4.5°F)

April 1 SWE (mm)

-3.6% -11.5%

-21.4% -34.8%

Transboundary ImplicationsTransboundary Implications

Changes in Simulated April 1 Snowpack for the Canadian and US portions of theColumbia River Basin

The Columbia River TreatyThe Columbia River TreatyThe Columbia River Treaty



8

ConservationConservationConservation

??

Joint management for multiple uses

Flexibility

New structures



9

PNW Climate Change:Implications for Washington Water Law

Prof. Michael Robinson-DornUniversity of Washington School of LawDirector, Kathy & Steve Berman Law Clinic

June 5, 2007Water Law Seminar

Key Trends in 20Key Trends in 20thth Century Climate Century Climate

Average annualtemperature increased+1.5°F in the PNWduring the 20th century

April 1 snowpack hasdecreased throughoutthe PNW with losses of30-60% at manyindividual stations(1950-2000)

Similar declines areseen throughout thewestern United States

3.6 °F

2.7 °F

1.8 °F0.9 °F

Cooler Warmer

Mote 2003(a), updated

Temperature Trends (°F per century), since 1920

Decrease Increase

Decrease Increase

Documents

PNW Climate Change - Law Seminars International robinson-dorn... · 2012-06-16 · PNW Climate Change: ... • More precipitation will fall as rain than snow. ... • Sea level rise