planning for drought - isws.illinois.edu · introduction 1. climatic conditions are major factors...

Planning For DroughtPlanning For Drought

Derek Winstanley, ChiefIllinois State Water SurveyIllinois State Water Survey

Illinois Department of Natural Resources

2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future

Contents

IntroductionHistorical droughtsResponse of surface waters and groundwaterWater supplies, use, and demandF t d htFuture droughtsDrought analyses for CMAP/Regional Water Supply Planning gRecommendations

2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future

Introduction

1. Climatic conditions are major factors in water supply and water demandD ht (l i it ti d hi h t t )2. Droughts (low precipitation and high temperatures) reduce water availability and increase water demand


The Water CycleThe Water Cycle

PRECIPITATION RUNOFF RECHARGE2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future2007 Priority Places Workshop: Implementing a Sustainable Water Supply for Kane County’s Future

PRECIPITATION RUNOFF RECHARGE

Annual Precipitation – Marengo IllinoisAnnual Precipitation Marengo, Illinois


Drought EffectsDrought Effects

Reduces streamflow (10% precipitation decline typically results in a 20-40% streamflow reduction)streamflow reduction)Decreases water levels in shallow wellsDeep aquifers are buffered from drought but could be impacted by long-term

climate change.


Increases water demand (peak use up to 50-60% higher than average daily use).

Relationship of Increased WaterRelationship of Increased Water Demand to Plant Capacity

22

Pl t C it

14

1820

Increased

Demand during

Plant Capacity(mgd)

Increaseddemand during drought

gdroughtexceeds plant

Average daily

demand

0

drought plantcapacity

demand


0

Public Bodies of Water in IllinoisPublic Bodies of Water in Illinois

The State’s authority toThe State s authority to protect flows extends only to these rivers.


Vern Knapp (ISWS)

Protecting Instream FlowsProtecting Instream FlowsStreamflow is usually abundant and its use for water supply is not a concern in most years But during lowsupply is not a concern in most years. But during low flows, instream flow uses become a priority issue.


Vern Knapp (ISWS)

Future Climate

Natural processes and human influences affect future climate.Th t id t ibl f t li tThere are two guides to possible future climate conditions

The past record (what has occurred can occur again)Climate modeling


Future Droughts Based on HistoryFuture Droughts Based on HistoryExpected Precipitation in Kane County(mean annual precipitation:36 inches,1971–2000; 25 inches, 2005)

Drought duration 50-year return period

200-year return periodp p

12 months 19 151524 months 24 2160 months 28 26


1 in 200 Year Drought1 in 200 Year Drought(ISWS Informational/Educational Materials 2006-02)


Illinois Annual Temperature:Illinois Annual Temperature: Departure from 1971–2000 Normal

Illinois Annual Temperature Departure from 1971 2000 NormalIllinois Annual Temperature Departure from 1971-2000 Normal

12

14

F)

6

8

10

e D

epar

ture

(F

0

2

4

Tem

pera

ture

-2

0

1825 1850 1875 1900 1925 1950 1975 2000 2025 2050 2075 2100

Year


20th Century A2 5th A2 95th A1B 5th A1B 95th B1 5th B1 95th

http://www.sws.uiuc.edu/wsp/climate/ClimateTom_scenariosmap2.asp

Illinois Annual Precipitation:Illinois Annual Precipitation:Departure from 1971–2000 Normal


http://www.sws.uiuc.edu/wsp/climate/ClimateTom_scenariosmap1.asp

Annual Precipitation – Marengo IllinoisAnnual Precipitation Marengo, Illinois


Future Droughts Based on HistoryFuture Droughts Based on HistoryExpected Precipitation in Kane County(mean annual precipitation:1971–2000, 36 inches; in 2005, 25 inches)

Drought duration 50-year return period

200-year return periodp p

12 months 19 151524 months 24 2160 months 28 26


Northeastern Illinois Regional Water SupplyNortheastern Illinois Regional Water Supply Planning Group

Analyze water supply and demand to 2050Temperature change: 0 to +6ºFPrecipitation change: -5 inches to +5 inchesPrecipitation change: -5 inches to +5 inches


Managing Water Supplies

Plan and be prepared for drought.Know your risks and costs.Increase supply: additional withdrawals and treatment plants; increased costDecrease demand: conservation (voluntary andDecrease demand: conservation (voluntary and mandatory); water reuse


planning for drought - isws.illinois.edu · introduction 1. climatic conditions are major factors...

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