rationalizing the 1962-2006 drop in water levels of lakes michigan and huron

Rationalizing the 1962-2006 Drop in Water Levels of Lakes Michigan and HuronSyed M. A. Moin, IJC Ottawa Anthony J. Eberhardt, USACE, VA

3rd International Conference on Current & Future State of Water Resources and Environment

Chennai, IndiaJanuary 7, 2010

Paper OutlineStudy area and objectivesDefining the issuesStudy organizationStudy approach & peer review processStudy strategyScientific and technical projectsScience questions & key findings

2010/01/07 2EWRI Conference - Chennai, India

Study Area

Lake Superior Outflow & Lakes Michigan -Huron

Inflow

Lake Huron Outflow & St. Clair River Inflow

Harbor Beach, Michigan

Cleveland, Ohio


4

Study Objectives To investigate St. Clair River flow characteristics and

determine how the natural regime of the river has been changed by human activities.

Assess relative importance of St. Clair River conveyance, hydroclimatic and other factors in the decline in levels since 1997.

To investigate whether the current Lake Superior outflow management procedures could be improved considering evolving upper Great Lakes interests and climate change.

To make recommendation to the IJC on changes and actions that may be necessary.

To 2

009

To 2

012

2010/01/07 EWRI Conference - Chennai, India

2.2 m

2.4 m

2.6 m

2.8 m

21 ft

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25 ft

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27 ft

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1999

The Issues: Explaining the State of Lake Levels & Head Decline


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Independent Peer Review

Precise Metrics & Proper

Methodology

Qualified & Experienced Personnel

CoreScience

QuestionsSediment

FactorsHydraulic &GIA Factors

HydroclimaticFactors

Histor

ical

Data A

nalys

isSupplem

entary

Field Measurem

ents

Modelling

Methodology / Strategies

Sub-products Synthesis Final Report

Multiple Thematic ApproachIndependent Peer Review

IUGLS Study Organization - Management Framework

Lake SuperiorRegulationTask Team

InternationalJoint

Commission

Public /Stakeholders

IJC StudyLiaison

Independent ReviewGroup

Communications Group

IUGLSStudyBoard

StudyManagers

PublicInterest Advisory

Group

InformationManagementPhysical Data &

Visualization

Continued withTask Framework

St. Clair RiverTask Team

Continued fromManagement Framework

Lake SuperiorRegulationTask TeamPlan

Evaluation

Coastal ZoneEcosystem

Water Uses

CommercialNavigation

Hydro

Recreation Boating & Tourism

DataVerification &Reconciliation

Surveys &Monitoring

Hydraulic Modelling

Sediment Studies

Mitigation Issues(if required)

Hydroclimatic

St. Clair RiverTask Team

IUGLS Study Organization - Task Framework

Setting the Studies


Sediment Science Questions:Has the "Morphology" of the St. Clair River been altered since the 1962 dredging?

a) Is the St. Clair River bed stable or eroding?b) If the bed of the St Clair river is eroding, what initiated it, and when?

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1. Bathymetry changed between 1971 and 2007 (an enlarged channel).

2. Since 2000 there has been no net change in the bathymetry.

3. There is a limited bed mobility (bed forms) but no net change.

4. Shear stresses along entire river are insufficient to erode the bed.

5. Shipping, ice jams can increase shear stress.

HydraulicScience Questions:What is causing the declining head difference between Lake Michigan-Huron and Lake Erie?

a) Has the conveyance capacity of the St. Clair River changed since 1962?b) If the conveyance capacity has changed what were the causes?

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1. Increase in conveyance capacity accounts for 11 cm decrease in Lake Huron level between 1971 and 2000 and is now stable.

2. Conveyance capacity increased by about 270 m3/s (less than 5% of the mean flow) for a brief period in the mid 1980s.

3. About 88% of the change in conveyance has occurred in the lower river. The mouth of the river is not a control section.

4. Conveyance probably changed in mid 1980s due to ice jam (1984).

Hydroclimatic

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1. Hydroclimatic models suggest that increased conveyance capacity (8-9 cm/3.5 in) and climatic factors (9-27 cm/3.5 to 10.5 in) account for a drop of Lake Michigan-Huron between 1986-2005.

2. From 1962 to 1986, climate and conveyance were major factors.

3. Climate was by far the major factor for 1996 to 2005 period.

• Science Question:How has climate affected the change in lake level relationship between Lake Michigan-Huron and Lake Erie?

12Mul

tiple

Them

atic R

esul

tsType of Analysis

Water Level Change

Flow Change

1-D Basic HEC-RAS Modelling 10 cm (3.9 in)290 m3/s

(10,233 ft3/s)

1-D Inverse HEC-RAS Modelling -320 m3/s

(11,292 ft3/s)

1-D Conveyance analysis* 2.5 to 3.2% 140 - 290 m3/s(4940 to 9350 ft3/s)

RMA2 2-D Modelling 12 cm (4.7 in)290 m3/s

(10,233 ft3/s)TELEMAC 2-D Modelling 13 cm (5.1 in) -

HydroSed 2-D Sediment Modelling 9 cm (3.6 in) -

Lake-to-lake water level analysis8 to 10 cm

(3.1 to 3.9 in) -

Gauge-to-gauge water level analysisUp to 14 cm

(5.5 cm) -

Flow generation with HPG**-

170 m3/s (6000 ft3/s)

HPG analysis 12 cm (4.7 in)290 m3/s

(10,233 ft3/s)Stage-Fall-Discharge equation analysis 8 cm (3.1 in) -

Mid-lakes Routing 13 cm (5.1 in) -Coordinated Routing - Component 8 cm (3.1 in) -Coordinated Routing - Residual 7 cm (2. 8 in)

Deterministic Mid-lakes Routing 7 cm (2. 8 in) -

Hydraulic Modelling

Data and Flow Analysis

Hydroclimate Modelling

* Change expressed as percent change in conveyance since 1971** Value reported from dynamic simulation of flows; average change reported.

Explaining the Decline


Principal RecommendationsCompensation Measures

Remedial measures not be undertaken in the St. Clair River at this time.

Addressing Effects of Long-Term Climate Change

The need for mitigative measures in the St. Clair River be examined as part of the comprehensive assessment of the future effects of climate change on water supplies in the upper Great Lakes basin in Report 2 of the Study, on Lake Superior regulation.


“Legacy” RecommendationsStrengthening Data Collection

Conduct bathymetric surveys every five yearsSupport the operation of the Study’s four new stream flow gauging stationsMaintain the operation of the two eddy co-variance (evaporation) gauges

Accountability Structure
