1. ENSC 202 – 2004 Phase 1 Steps 2-5 Watershed Assessment (ENSC 202) Phase 1 – Steps 2-5 Extracted from Vermont ANR Stream Geomorphic Assessment Protocols Handbook - Introduction

2. ENSC 202 – 2004 Phase 1 Steps 2-5 Step 2 Determining Stream Types 2.1 Downstream and Upstream Elevations 2.2 Valley Length 2.3 Valley Slope 2.4 Channel Length 2.5 Channel Slope 2.6 Sinuosity 2.7 Watershed Size 2.8 Channel Width 2.9 Valley Width 2.10 Confinement 2.11 Stream Type

3. ENSC 202 – 2004 Phase 1 Steps 2-5 Notes on Step 2 This is a first cut only, don’t sweat it. Focus is on what the reach might be like in the absence of human influences – a true reference. Be consistent in how you make each measurement. Be consistent with your measurement units. Potential measuring tools: ruler, map wheel, GPS mapping tools, GIS

4. ENSC 202 – 2004 Phase 1 Steps 2-5 Step 2.1 Downstream & Upstream elevations –Point at which contour crosses stream –Interpolate between contours Step 2.2 Valley length –Straight line distance between reach breaks –Follow tendency (valley walls) not meanders Step 2.3 Valley slope –(change in elevation/valley length)*100 Step 2.4 Channel length –Actual channel (thalweg) distance –Note difference from Valley Length (2.2) Step 2.5 Channel slope –(change in elevation/channel length)*100 Step 2.6 Sinuosity –Channel length/valley length

5. ENSC 202 – 2004 Phase 1 Steps 2-5 Step 2.7 Watershed size –Drainage area above downstream reach break for each reach –GIS, planimeter, or graph paper methods Step 2.8 Reference channel width (provisional) –Based on regional hydrologic geometryregional hydrologic geometry –Limitations: mid-to-large sized streams in unconfined, moderate- to-gentle gradient, alluvial settings –Make best guesses now, you can adjust this later with field data from confirmed ‘reference’ reaches Step 2.9 Valley width –Measure width between the first lateral contours next to the stream (hard in confined valleys) –Make ~10 measurements per reach/valley and average

6. ENSC 202 – 2004 Phase 1 Steps 2-5 Vermont Regional Geometry Curves 95% confidence intervals

7. ENSC 202 – 2004 Phase 1 Steps 2-5 Step 2.10 Confinement (provisional) –(valley width/channel width) 2.9/2.8 Step 2.11 Reference stream type (Appendix I)Appendix I –Based on Rosgen (1996) and Montgomery & Buffington (1997)

8. ENSC 202 – 2004 Phase 1 Steps 2-5 Step 3 Basin Characteristics: Geology and Soils 3.1 Alluvial Fan 3.2 Grade Controls 3.3 Geologic Materials 3.4 Valley Side Slopes 3.5 Soil Characteristics

9. ENSC 202 – 2004 Phase 1 Steps 2-5 Step 3.1 Alluvial Fans (Y/N)

10. ENSC 202 – 2004 Phase 1 Steps 2-5 Step 3.2 Grade controls Step 3.3 Geologic materials NRCS ‘Top 20’ soils (?) Defining channel corridor (Appendix E)Appendix E

11. ENSC 202 – 2004 Phase 1 Steps 2-5 Step 3.4 Valley side slope –Directly from topo maps Step 3.5 Soil characteristics –Hydrologic Group –Flooding –Water Table –Erodibility

12. ENSC 202 – 2004 Phase 1 Steps 2-5 Step 4 Land Cover and Reach Hydrology 4.1 Watershed Land Cover / Land Use 4.2 Corridor Land Cover / Land Use 4.3 Riparian Buffer Width 4.4 Groundwater and Small Tributary Inputs General characterizations based on observations of older and more current maps, orthophotographs, existing data, or windshield surveys.

13. ENSC 202 – 2004 Phase 1 Steps 2-5 Step 4.1 Watershed Land Cover and Land Use –Current = best available –Historic = 1970’s orthophotos –Assign impact rating Step 4.2 Corridor Land Cover and Land Use –Current = best available –Historic = 1970’s orthophotos –Assign impact rating

14. ENSC 202 – 2004 Phase 1 Steps 2-5 Step 4.3 Riparian buffer widths –‘left’ vs ‘right’ bank –Record dominant buffer width by bank –Note particular restoration opportunities Step 4.4 Groundwater & small tributray inputs (wetlands) –No impact rating?

15. ENSC 202 – 2004 Phase 1 Steps 2-5 Step 5 In-stream Channel Modifications 5.1 Flow Regulations and Water Withdrawals 5.2 Bridges & Culverts 5.3 Bank Armoring or Revetments 5.4 Channel Modifications 5.5 Dredging and Gravel Mining History

16. ENSC 202 – 2004 Phase 1 Steps 2-5 Step 5.1 Flow regulation and water withdrawals –Consult with DEC, town records, utilities Step 5.2 Bridges and culverts –Count number –Will probably have to be augmented with windshield surveys

17. ENSC 202 – 2004 Phase 1 Steps 2-5 Step 5.3 Bank armoring and revetments –Will probably have to be augmented with windshield surveys –%armoring = (RB armor length + LB armor length – overlap) (total RB+RL length)

18. ENSC 202 – 2004 Phase 1 Steps 2-5 Step 5.4 Channel modifications –Will probably have to be augmented with windshield surveys Step 5.5 Dredging and gravel mining history –DEC Stream Alteration Engineers, town records, road commissioners –Will probably have to be augmented with windshield surveys