Hydrologic Analysis for NPS Grants

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Hydrologic Analysis for NPS 319 and CMI Grants
Hydrologic Analysis for NPS 319 and CMI Grants
Dave Fongers, HSU, MDEQ, 517-373-0210,
fongersd_at_michigan.gov
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Definitions

• Hydrology the occurrence, distribution, and
  movement of water both on and under the earth's
  surface.
• Stream Morphology the form and structure of a
  stream (sinuosity, profile, and cross-sectional
  dimensions).
• Morphologic Stability no net change in channel
  shape, which occurs only if the channel-forming
  flow is also stable. A stable stream will have
  natural erosion.

Hydrologic changes can cause a stream to be
unstable for 60 years or more.
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Channel-Forming Flow is the flood discharge that
causes the channel to assume its existing shape.

• Extreme flood flows generally have little effect
  on channel morphology because they are so rare.
  More frequent flows, those that recur about every
  1.5 to 2-years, are generally the dominant
  channel-forming flows in stable, natural streams
  (Schueler, 1987 and Rosgen, 1996).

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Increase Flow or Slope
Increase Sediment, Erosion

• Water can carry 64 times larger particles if the
  velocity is doubled.

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Hager Creek
Instability is indicated by extensive, excessive
erosion, especially along straight reaches.
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Hager Creek
Down-cuts are good indicators of instability.
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Hager Creek
A more typical down-cut.
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Goals of NPS Hydrologic Analysis

• Help identify the cause(s) of streambank erosion
• Facilitate the selection and design of suitable
  stabilization BMPs
• Understand and plan for future hydrologic change
• Help define critical areas for the Watershed
  Management Plan

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Goals of NPS Hydrologic Analysis

• Help identify the cause(s) of streambank erosion
• Facilitate the selection and design of suitable
  stabilization BMPs
• Understand and plan for future hydrologic change
• Help define critical areas for the Watershed
  Management Plan

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A. ID erosion causes
Blakeslee Creek
Land Use Change
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Blakeslee Creek
A. ID erosion causes
70 increase in peak flow, 170 increase in
runoff volume, former instantaneous peak flow now
lasts 4 hours
Pre-development
Post-development
Predicted 50 percent chance (2-year) flow from
calibrated model.
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Blakeslee Creek
Instability is indicated by extensive, excessive
erosion, especially along straight reaches.
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Gage Analysis
A. ID erosion causes
Gage Analysis
4712 cfs 67 (1.5-year), 6368 cfs 50 (2-year),
10397 cfs 10 (10-year)
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Gage Analysis
A. ID erosion causes
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A. ID erosion causes
Pine River
Livestock
Cause
Cause
Cause
Cause
Cause
Cause
Cause
Sometimes the cause of the erosion is obvious.
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A. ID erosion causes
Foot Traffic
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Bear Creek
A. ID erosion causes
Flow Obstructions
This erosion may be caused by flow diverting
around debris or ice piling against the former
bridge supports. Nearby streambanks are stable.
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A. ID erosion causes
Natural Erosion
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Goals of NPS Hydrologic Analysis

• Help identify the cause(s) of streambank erosion
• Facilitate the selection and design of suitable
  stabilization BMPs
• Understand and plan for future hydrologic change
• Help define critical areas for the Watershed
  Management Plan

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Flemings/River Rouge
B. BMP design
This CMI-funded detention ponds drainage area is
nearly fully developed. Based on the grantees
hydrologic analysis, the 2-year event release
rate is 0.018 cfs/acre.
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East Branch AuGres River
A. ID erosion causes
This erosion started 80 years ago when fourteen
miles of natural stream was diverted to a
three-mile long, straight channel. The
hydrologic study provided design flows.
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Hager Creek
B. BMP design
Hydrologic analysis provided design flows.
Hydraulic analysis verified the effect of the
proposed channel changes.
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Goals of NPS Hydrologic Analysis

• Help identify the cause(s) of streambank erosion
• Facilitate the selection and design of suitable
  stabilization BMPs
• Understand and plan for future hydrologic change
• Help define critical areas for the Watershed
  Management Plan

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Black River
C. Plan for future changes
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Black River, 4 storm
C. Plan for future changes
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Sand Creek
C. Plan for future changes
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Sand Creek
C. Plan for future changes
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Sand Creek
C. Plan for future changes
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Sand Creek
C. Plan for future changes
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Sand Creek
C. Plan for future changes
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C. Plan for future changes
0.13
0.05
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C. Plan for future changes
From Gun River Hydrologic and Hydraulic Study,
Appendix 6
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C. Plan for future changes
From Gun River Hydrologic and Hydraulic Study,
Appendix 6
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Goals of NPS Hydrologic Analysis

• Help identify the cause(s) of streambank erosion
• Facilitate the selection and design of suitable
  stabilization BMPs
• Understand and plan for future hydrologic change
• Help define critical areas for the Watershed
  Management Plan

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D. Define critical areas
Excerpt from Coldwater River Watershed Management
Plan, Tables 13 14