Presentation given by Conor Gillespie on June 4, 2012 at the Third Annual Choose Clean Water Conference.

1. Cost / Benefit Analysis
for the
Restoration of
Riverine Systems Impacted by
Legacy Sediment
Presented to
2012 Choose Clean Water Conference
Lancaster, PA
By
Conor Gillespie, CPESC, MBA
Conor@landstudies.com
May 2012

2. Existing Conditions
Legacy Sediment
Hydric Soils
Basal Gravels
Legacy Sediment is the impairment to the aquatic resource

3. Hard Armor Approach
Cost $200 - $250 / lf
Existing Grade
Legacy Sediment
Hydric Soils
Basal Gravels
Imbricated Wall Artificially Elevated Streambed
Short Term Benefit Long Term Risk
- Reduced erosion of impairment - Failure of armoring resulting in
- Minimal improvement to aquatic resource renewed erosion of impairment

4. Soft Armor Approach
Cost $100 - $150 / lf
Existing Grade
Legacy Sediment
Hydric Soils
Basal Gravels
Bioengineering
Short Term Benefit Long Term Risk
- Reduced erosion of impairment - Failure of bioengineering resulting
- Moderate improvement to aquatic in renewed erosion of impairment
resource

5. Floodplain Restoration
Cost $100 - $200 / lf
Existing Grade
Hydric Soils
Basal Gravels
Short & Long Term Benefit
- Removal of impairment
- Restored function of aquatic resource

6. Natural Piedmont Stream Valley
Connectivity
between
Rooting Zone,
Groundwater,
and
Stream Flow
Roots extend
to groundwater Cobble/Gravel Bed
Floodplain Soils – (Groundwater) Bedrock
Shallow, Peaty,
Organic, & Porous

7. Hydrologic Functions: Maximizing
Sediment, Nutrient, and Carbon
Retention in Natural Systems
Beaver Dam Controlled Stream Marshland

8. Potential Objectives of Riverine System
Restoration
 Sediment and Nutrient Reduction
 Groundwater Recharge
 Stormwater Management
 Wetland Creation
 Regional Flood Reduction
 Carbon Retention
 Wildlife Habitat Improvement
 Invasive Species Removal
 Fisheries Improvements
 Thermal Improvements – Base Flow

9. Big Spring Run Restoration
Restore the natural floodplain, stream and riparian wetland
functions to its natural ecological potential.
Maximize removal of nutrients and sediments
Small headwater stream/springs – characteristic of a sedge
dominated wet meadow – Bog Turtle Habitat.
Areas seasonally flooded and extremely wet.
Frequent exchange and interaction between channels and
floodplain.
Over time, vegetation will encroach upon the channel increasing
carbon, nutrient and sediment retention. The objectives will
improve over time and not be considered optimum immediately
after restoration similar to the previous projects discussed.

10. Full-Depth Floodplain Restoration
Design Features
 Channel directly linked to groundwater/bedrock.
 Floodplain Elevation – Preferably 6 to 12 inches with
vernal pools to maximize – retention areas. This allows
the root zone to quickly access and stabilize the
floodplain.
 Planform is sinuous, single, multi-thread channel or no
defined channel; similar to headwater marshes or wet
meadows.
 Maximize width of floodplain and condition soils for
vegetation/root penetration.
 Woody debris throughout channel(s) & floodplain.

11. Big Spring Run
Pre-settlement floodplain

16. Cost Benefit Analysis
Big Spring Run Case Study
3,060 lf of Restoration
Benefit Value Hard Armor Soft Armor Floodplain
$225 $125 Restoration
$170
Total Cost $688,500 $382,500 $522,500
Stream Mitigation Dollar Values Vary Mitigation Possibly Mitigation Mitigation Achieved
by State Achieved Achieved
Wetland Mitigation $77,500 / ac $0 $0 $310,000
$ / ac* ($60,000 - $85,000) (4 ac)
Wildlife Habitat Conservation Minimal Medium Maximum
Banking Credits
Sediment / Nutrient N – $3.37 ??? / yr ??? / yr ??? / yr
Reduction (On-site)** P – $4.73 Short term Short term Long Term
Sediment / Nutrient N – $3.37 $0 / yr $0 / yr ??? / yr
from upstream sources P – $4.73 Transport Transport Retention
Legacy Sediment Re- $14 $2,380 $4,760 $280,000
use*** $3 - $25 / cy (170 cy) (340 cy) (20,000 cy)
Floodwater Storage None Minimal 12 ac/ft
Infrastructure Maint. Likely Likely Minimal
Requirements
*Courtesy of Resource Environmental Solutions, LLC; Estimated Wetland Mitigation Credit Prices for the State of PA based off
current market conditions
** Prices based of results of PennVEST Spot and Forward Nutrient Auctions; October 28, 2010 - March 21, 2012
*** Courtesy of Joe Sweeney, based on estimated re-sale value of Legacy Sediment from Big Spring Run project

17. Cost Benefit Analysis
Big Spring Run Case Study
3,060 lf of Restoration
Benefit Value Hard Armor Soft Armor Floodplain
$225 $125 Restoration
$170
Total Cost $688,500 $382,500 $522,500
Total Monetary Benefit $2,380 $4,760 $590,000
Simple Return on - 99.65% - 98.75% 12.9%
Investment
Additional Site Specific Benefits with Monetary Value
- Sustainable, Low Impact Site Development
- On-site water retention and usage
- Reduction in stormwater fee’s due to increased infiltration
Future Market Drivers
- MS4 Permit Requirements
- Chesapeake Bay TMDL’s
- Wetland Creation & Mitigation

18. Thank You