Instream-Flow StudyNorth Fork ShenandoahRiver

Jennifer L. Krstolic and Donald C. Hayes

Knowledge Gained

Physical Habitat Classified

Fish Species Documented

Low-Flow Water Qualityhttp://water.usgs.gov/pubs/sir/2004/5153/

Stage-Discharge Relation

Habitat-Flow Relation

Water-Quality During Low-Flow Periods

Diurnal patterns of DO showed large fluctuations

pH values higher than State standard found only at downstream end

Water temperatures within State standards

Water-Quality Questions Raised

How does DO fluctuate during normal summer flows?

What processes most influence pH values?

How does ground-water discharge affect water temperature?

Modeling Results

Usable Area Totals for the Upper North Fork Shenandoah River

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10 100 1000 10000

ST RASBURG FLOWS I N CFS

Fis

h G

uild

Use

able

Are

a

0

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

4,500

5,000

Can

oein

g U

seab

le A

rea

Riff le Fast Generalist Pool Run Pool Cover Canoeing

Normal Range of f lows 112 - 272 cfs Aug, Sept, Oct

Interpretation

Cootes Store days per month less than 1.6 cfs (1 MGD)90 percent exceedence value

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35

1925

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YEAR

NU

MB

ER O

F D

AYS

july 1.6 cfs or less August 1.6 cfs or less September 1.6 cfs or less October 1.6 cfs or less

Application: Drought Flows and Habitat

Weighted Usable Area Totals for the Upper North Fork Shenandoah River Reach Represented by the USGS Gaging Station at Cootes Store, Va.

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0.1 1 10 100 1000 10000LOG OF FLOW IN CFS

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ITA

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S

0

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WU

A C

AN

OEI

NG

Riffle Guild Habitat Curve Fast Generalist Guild Habitat Curve Pool Run Guild Habitat CurvePool Cover Guild Habitat Curve 90% canoeing

Normal Range of flows 3.6 - 42 cfs

Next Steps for the North Fork

Adoption of Thresholds and proposal to policy makers

Un-permitted Water Withdrawal Study

Further investigation into water quality on the North Fork

Instream-Flow StudySouth Fork ShenandoahRiver

Proposed South Fork Research

Sister study with similar research components

PHABSIM modeling with additional water-quality monitoring

Connecting surface-water and ground-water research efforts

Proposed South Fork Research

Proposed South Fork Research

Physical Habitat Classification with more geomorphology

Low-Flow and Normal-Flow Water-Quality studies

Habitat-Flow Relation tied to stream gages for three sections of the South Fork Shenandoah River

Transfer of North Fork basin and flow characteristics to the South Fork tributaries

Proposed South Fork Research Timeline

2005 - 2007

Physical-Habitat Mapping, Water-Quality Survey, Reach Selection, Transfer Basin Characteristics, Publications

2008 - 2010

Hydraulic-Data collection, Modeling, Analysis, Publication

South Fork Companion Investigations

Fish Habitat Needs-Assessment

Estimated Un-permitted Water Withdrawal Study

Shenandoah Valley Water Withdrawals Pilot Study

Identify and document actual use by permit holders

Locate unregulated water users

Apply methods to measure and estimate water use

Questions?