A Geomorphic Comparison A Geomorphic Comparison of an Attainment and an of an Attainment and an

Impaired Stream in Impaired Stream in Vermont: Potash and Allen Vermont: Potash and Allen

BrooksBrooks

Jen Fullerton, Travis Smith, Jen Fullerton, Travis Smith, Joe Bartlett, Sarah Palmer, Joe Bartlett, Sarah Palmer,

and Nat Morseand Nat MorsePrepared for ENSC 202Prepared for ENSC 202

May 13, 2004May 13, 2004

Presentation OutlinePresentation Outline

Methods/Site Methods/Site SelectionSelection

Reach DescriptionsReach Descriptions

ResultsResults

DiscussionDiscussion

Methods/Site SelectionMethods/Site Selection

Chose attainment stream according to the Chose attainment stream according to the watershed size of Potash Brook (~20 kmwatershed size of Potash Brook (~20 km22))

Selected 3 similar reaches on each stream Selected 3 similar reaches on each stream using various stream characteristics using various stream characteristics determined by a site visitdetermined by a site visit

Bed MaterialBed Material Riparian VegetationRiparian Vegetation SinuositySinuosity Stream TypeStream Type

Completed Phase 1 (SGAT) and Steps 6 & 7 of Completed Phase 1 (SGAT) and Steps 6 & 7 of Phase 2 of the Stream Geomorphic Assessment Phase 2 of the Stream Geomorphic Assessment

Attainment Reaches – Attainment Reaches – Allen BookAllen Book

Impaired Reaches 1 & 2 - Impaired Reaches 1 & 2 - Potash BrookPotash Brook

Impaired Reach 3 - Impaired Reach 3 - Potash BrookPotash Brook

Potash Reach OnePotash Reach One

-Channelized and armored banks

-Medium gradient riffle-pool

-Riparian buffer greater than 100 ft

Potash Reach TwoPotash Reach Two

-Unconfined

-Low gradient ripple-dune formations

-Riparian buffer less then 100 ft

Potash Reach ThreePotash Reach Three

-Straightened and armored on the left bank

-Transitions from a straightened moderate

gradient to a wide deep pool formation

-Riparian buffer less then 50 ft

Allen Brook Reach OneAllen Brook Reach One

-Medium gradient riffle-pool formations

-Riparian buffer greater than 100 ft

Allen Brook Reach TwoAllen Brook Reach Two

-Low gradient dune-ripple formations

-Riparian buffer greater than 100 ft

Allen Brook Reach ThreeAllen Brook Reach Three

-Low gradient dune-ripple formations

-Riparian buffer greater than 100 ft

Phase 1 ResultsPhase 1 ResultsPhase 1 Adjustment Scores

6

7

5

8

6

7 7

44

7

4

2

11

9

7

11

10

9 9

8

11

9

7

13

0

2

4

6

8

10

12

14

Degredation Aggredation Widening Planform

Adjustment Process

Pre

dic

ted

Im

pact

Sco

re

Allen 1

Allen 2

Allen 3

Potash 1

Potash 2

Potash 3

Predicted impact score for adjustment process for each reach using SGAT (higher scores indicate greater degradation)

Phase 2 Results - RHAPhase 2 Results - RHAIndividual Rapid Habitat Assessment Scores

0

2

4

6

8

10

12

14

16

18

20

6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 6.10

Individual RHA scores

Valu

e

Allen Brook 1

Allen Brook 2

Allen Brook 3

Potash Brook 1

Potash Brook 2

Potash Brook 3

RHA scores for each reach(score of 20 indicates reference condition)

Phase 2 Results - RGAPhase 2 Results - RGARapid Geomorphic Assessment Scores

13

15

16 16

18

19

17 17

18 18

17

16

10

12

11

12

11

12

9

11

8

10

12

10

0

2

4

6

8

10

12

14

16

18

20

7.1 7.2 7.3 7.4

Individual RGA scores

Valu

es

Allen Brook 1

Allen Brook 2

Allen Brook 3

Potash Brook 1

Potash Brook 2

Potash Brook 3

RGA scores for each reach(score of 20 indicates reference condition)

Composite ResultsComposite Results

Condition, RHA, and RGA scores for each reach

Composite ResultsComposite ResultsRapid Habitat Assessment vs.Stream Condition

y = 0.7739x + 0.3334

R2 = 0.8464

0.4

0.5

0.6

0.7

0.8

0.9

1

0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00

Stream Condition

RH

A

Scatter plot with regression line for RHA vs. stream condition

Composite ResultsComposite ResultsRapid Geomorphic Assessment vs. Stream Condition

y = 0.9262x + 0.2944

R2 = 0.9039

0.4

0.5

0.6

0.7

0.8

0.9

1

0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 1.00

Stream Condition

RG

A

Scatter plot with regression line for RGA vs. stream condition

Composite ResultsComposite ResultsRapid Habitat Assessment vs. Rapid Geomorphic Assessment

y = 0.8223x + 0.0964

R2 = 0.9068

0.4

0.5

0.6

0.7

0.8

0.9

1

0.4 0.5 0.6 0.7 0.8 0.9 1

RGA

RH

A

Scatter plot with regression line for RHA vs. RGA

Factors Affecting Stream Factors Affecting Stream QualityQuality

Upstream land cover/land use vs. stream Upstream land cover/land use vs. stream corridor integrity (Potash 1 vs. Potash 2 corridor integrity (Potash 1 vs. Potash 2 and 3)and 3)

Issues with Stream Issues with Stream EngineeringEngineering

Rip-RapRip-Rap Sediment Sediment

depositiondeposition Bank failureBank failure

Adjustments Adjustments neededneeded Separate protocolSeparate protocol More categoriesMore categories

Using SGAT for Phase 1 Using SGAT for Phase 1 AssessmentAssessment

Increased confidence Increased confidence in values due to in values due to reduced subjectivity reduced subjectivity in assessmentin assessment

Problems with SGATProblems with SGAT 50 ft contour lines are 50 ft contour lines are

not accurate enough not accurate enough for delineation of for delineation of valley wallsvalley walls

Beaver ActivityBeaver Activity

Evidence of Beaver Evidence of Beaver Activity in 5 reachesActivity in 5 reaches

(Potash 1, 2, & 3, Allen 2 & 3)(Potash 1, 2, & 3, Allen 2 & 3)

May have lowered May have lowered RHA and RGA scoresRHA and RGA scores

Loss of riparian Loss of riparian vegetationvegetation

Decreased bank Decreased bank stabilitystability

ConclusionsConclusions

Urbanization in lower Potash Brook Urbanization in lower Potash Brook watershed impacted the watershed impacted the geomorphology of the streamgeomorphology of the stream

Riparian buffers and stream corridor Riparian buffers and stream corridor integrity are important in mitigating integrity are important in mitigating the effects of development on streamsthe effects of development on streams

Strategic watershed planning is needed Strategic watershed planning is needed to minimize the impacts of developmentto minimize the impacts of development

AcknowledgementsAcknowledgements Dr. Breck BowdenDr. Breck Bowden

Alex HackmanAlex Hackman

Mike KlineMike Kline

Doug BurnhamDoug Burnham

Staci PomeroyStaci Pomeroy