Description: The stream scoping application is used by county staff to determine if a stream is in need of restoration. Staff visit selected sites and input stream data into the app. Data collected in this manner helps prioritize future stormwater management improvement projects.
1. A Fairfax County, VA, publication
Department of Public Works and Environmental Services
Working for You!
Stream Scoping Application Overview
February 2018
5. Project Scoping Application
โField Formโ โ Site Overview Information (red stars)
5Stormwater Planning Division
โข Project Name, ID, Drainage
Area, and % Impervious are
pre-filled and do not need to
be changed
โข Field staff to complete
Scoping Team with member
names, date and weather
6. Project Scoping Application
โข Access, Utilities, Ownership,
and Stream Order are pre-
filled
โข These fields need to be
confirmed by the staff in the
field
โ If limits of site change,
easement and ownership may
also change
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โField Formโ โ Planning Score (red star)
Stormwater Planning Division
8. Project Scoping Application
โField Formโ โ Channel Dimensions
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โข New reach examples:
โ Change in channel dimensions
โ Change in vegetative buffer
โ Tributary confluence
โ Road crossing
โข Reaches are drawn in the
application and appear in
blue
Stormwater Planning Division
Image courtesy of Indiana Fluvial
Erosion Hazard Program
9. Project Scoping Application
โField Formโ โ Channel Dimensions
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โข A, W, and D from the
Urban NC Regional Curve
are pre-loaded in the site
data
โข Note this is based on the
DA at the pour point of
the site
Stormwater Planning Division
1
10
100
0.01 0.10 1.00 10.00
Cross-SectionalArea(sqft)
Drainage Area (sq mi)
Published Regional Curves for the
Piedmont Physiographic Region
NC Urban
(41% I.A.)
Graph
courtesy of
North
Carolina State
University
Cooperative
Extension
10. Project Scoping Application
โField Formโ โ Channel Dimensions
10Stormwater Planning Division
โข Pull down:
โ I โ Stable
โ II โ Incision
โ III โ Widening
โ IV โ Aggradation
โ V โ Quasi Stable
11. Project Scoping Application
Stormwater Planning Division
โField Formโ โ Reach Comments
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โข Bridges:
โ Note number, type and
condition
โ Drop a purple square
โScoping Issueโ
โข Outfall:
โ Note number, condition
(good, fair, poor) and if
work is needed
โ May be a note in Stormnet
Issues
โข Safety Issues:
โ May include infrastructure
loss
โ Note key attributes
(distance from top of
bank)
โ Drop a purple square
โScoping Issueโ
12. Project Scoping Application
Stormwater Planning Division
โField Formโ โ Reach Comments
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โข Buffer โ Left and Right:
โ Input in feet
โข Human Impact
โ May include trails,
infrastructure, mowing,
clearing, dumping,
stabilization projects
13. Project Scoping Application
โField Formโ โ Reach โ Instability Score
โข Based on BEHI (Bank Erosion
Hazard Index) and Pfankuch
Stability Index
โข Comprised of:
โ Four parameters:
โข Streambank vegetation
โข Bank slope
โข Mass wasting
โข Cutting of banks and bed
โ Adjustment points
โข Excessive aggradation
โข Excessive scour to bedrock
13Stormwater Planning Division
Image courtesy of Rosgen
14. Project Scoping Application
โField Formโ โ Instability Score - Vegetation
โข Immediate area at top of
bank
โข Rooting depth and
density
โข Think about the ability of
roots to hold the banks
โข This is NOT the condition
of the buffer or buffer
width
14Stormwater Planning Division
17. Project Scoping Application
โField Formโ โ Instability Score โ Mass Wasting
โข Mass wasting = slope failure
โข Downslope movement of
soil/rock typically as a mass,
largely under the force of
gravity but frequently
affected by water
17Stormwater Planning Division