potential project evaluation and prioritization indian and howard’s creeks local watershed plan...

Potential Project Evaluation and Prioritization

Indian and Howard’s Creeks Local Watershed PlanApril 23, 2009

Project Evaluation and Prioritization

• Stream Assessment Methods

• Stream Assessment Results

• Wetland Assessment Methods

• Wetland Assessment Results

• BMP Site Assessments

• Prioritization Methodology

• Stakeholder Input & NECBA

Stream Assessment Methods


Phased approach – EEP provided sites to assess from Phase 1– ENTRIX performed aerial photo and GIS

evaluations to prioritize sites for field work– ENTRIX performed field assessments on

40 potential stream restoration sites and 10 potential preservation reaches

– Preliminary prioritization based on field data


Aerial photo and GIS evaluations– 80 stream restoration sites evaluated (31.8

mi.)• 26 high priority sites based on EEP’s Phase 1• 43 medium priority sites based on Phase 1• 11 low priority sites based on Phase 1

(selected based on proximity to another project)

– 22 stream preservation sites evaluated (15.5 mi)

• All priority sites from Phase 1


Stream GIS and aerial photo evaluations included:

• Buffer vegetation condition

• Historic channelization

• Presence of bank erosion or sediment

deposition


Aerial photo buffer vegetation assessment

• Percentage of 50 foot buffer zone forested based on 2005 aerial photo– 0% to 25% forested cover– 26% to 50% forested cover– 51% to 75% forested cover– 76% to 100% forested cover


GIS-based assessment of channelization

• Based on comparison of historic aerials (1938, 1951, and/or 1968) with 2005 aerials

• Included consideration of topography

• Resulted in “channelized” or “not channelized”


Aerial photo assessment of erosion and sedimentation

• Reviewed aerial photos to identify areas where erosion or deposition were present

• Resulted in “erosion/sedimentation present” or erosion/sedimentation not present”


Field Assessments

• Two person crew evaluated 40 potential restoration

sites and 10 potential preservation sites

• Entire reach walked up to 3,000 ft. for restoration

sites or 5,000 ft. for preservation sites

• Reach boundaries located with GPS

• Digital images taken and field forms utilized to

document conditions


Field Assessments

• DWQ habitat assessment for piedmont and

mountain streams

• Stream bank stability assessment – modified

HEC-20 assessment

• Evaluation of channel hydraulic capacity

• Evaluation of Mitigation Project Potential


DWQ habitat evaluation• 8 riparian and in-stream habitat metrics:

– Evidence of channel modification– In-stream epifaunal habitat– Bottom substrates– Pool variety– Riffle habitats– Bank stability and vegetation– Canopy coverage– Riparian zone width


Channel stability assessment

• Watershed land use• Flow status• Channel pattern• Entrenchment/confinement• Bed material• Bar development

• Presence of obstructions

• Bank soil texture/coherence

• Bank angle• Bank vegetation• Bank cutting• Mass waisting/failure


Channel hydraulic capacity assessment• Cross-sectional area measured

– To top of bank– At representative riffle

• Flows computed with USGS regional regression equations for Q2 and Q10

• Channel gradient, roughness, and Q used to calculate flow area

• Ratio of calculated to measured flow area developed to identify channel enlargement

Stream Assessment Results


GIS-based prioritization for field assessment

• Reviewed and amended by EEP

• Forty stream restoration sites prioritized for

field assessment (+ alternates)

• Ten stream preservation sites prioritized for

field assessment

Stream Restoration Parameters

Buffer Percent Forested Channelized EEP Ranking Erosion

Value 0-25 25-50 50-75 75-100 Yes No High Med Low Yes No

Score 3 2 1 0 3 0 3 2 0 1 0

Stream Preservation Parameters

Buffer Percent Forested Channelized EEP Ranking

Value 0-25 25-50 50-75 75-100 Yes No High Med Low

Score 0 1 2 3 0 3 3 2 0


GIS assessment results

Stream Restoration Site Examples

R-90 Howard’s Creek Middle

R-61 Howard’s Creek Middle

R-77 Howard’s Creek

R-31 Mill Creek

R-51 UT to Howard’s Creek Upper

Stream Preservation Site Examples

P-10 Howard’s Creek

P-6 Indian Creek Upper

P-31 Indian Creek Upper

Wetland Assessment Methods


Phased approach – EEP provided 59 sites to assess from

Phase 1– ENTRIX performed aerial photo and GIS

evaluations to prioritize sites for field work– ENTRIX performed field assessments on

30 potential wetland restoration sites– Preliminary prioritization based on field

data


Aerial photo and GIS evaluations

• 57 wetland restoration sites evaluated

• All priority sites from Phase 1 – 2005 aerial photographs,

– Soils GIS data (NRCS, 2007),

– Topography data (EEP, 2008

– NWI data (USFWS, 1999).


GIS-based wetlands assessments• Determination of mapped hydric soils• Extent of wetland vegetation

– no vegetation– partially-vegetated– fully-vegetated

• Proximity to NWI wetland• Proximity to potential stream project

Wetlands Assessment Methods

Field Assessments

• ENTRIX evaluated 30 potential restoration sites

• Utilized standard USACOE assessment methodology:

1. Hydric Soils Evaluations– Two borings per site

2. Hydrology Assessment– Primary and secondary indicators of wetland hydrology on the USACOE form

were evaluated.

3. Vegetation Characterization– A qualitative vegetation survey - several locations at each site. Dominant

plant species documented based on NRCS Plant Databases indicator code. Indicator status will be recorded.


DWQ staff evaluated 67 potential preservation sites (DWQ, October, 2008)

– To identify and assess a random sample of jurisdictional wetlands within the Indian/Howard’s Cr. LWP area;

– To calculate restoration equivalents based on potential for enhancement at each of the assessed jurisdictional wetlands, where appropriate;

– To characterize the level of functioning of wetlands as a whole throughout the LWP area by using a stratified random sampling design.

Wetland Assessment Results


• GIS-based prioritization for field assessment

• Reviewed and amended by EEP

• Thirty wetland restoration sites prioritized for field assessment (+ alternates)


Wetland Restoration Parameters

Vegetation NWI EEP Ranking

Adjacent to Stream

Restoration Opportunity

Value Fully Partially No Yes Nearby No High Med Low Yes No

Score 0 1.5 3 3 2 1 3 2 0 3 0

GIS assessment results


• Add in maps, tables, and pictures

Wetland Restoration Site Examples

W-30 Howard’s Creek

W-39 Middle South Fork Upper

W-44 Middle South Fork Upper

W-80 Howard’s Creek

W-25 Tanyard Creek

Potential BMP Site Assessments

Potential BMP Site Assessments

• Potential locations for BMPs identified through GIS analysis– Available space– Urban watershed– Topography/drainage

• Preliminary field site review of each potential facility

• Site reviews performed for 10 sites

Site quality – Medium

Potential BMP type – Bioretention, swale

Construction access – Excellent

Treatment area – Bus and car parking lot (approx. 0.7 acres)

BMP-2 Cherryville HS

Site quality – High

Potential BMP type – Bioretention, swale, and/or wetland


Treatment area – Parking lot (up to approx. 2.3 acres)

BMP-8 West Lincoln HS

Site quality – Medium

Potential BMP type – Bioretention


Treatment area – Parking lot (up to approx. 0.2 acres)

BMP-4 First Baptist Church

Prioritization Methodology

Prioritization Methodology

• Step 1: GIS analysis• Step 2: Field Assessment• Step 3: Develop project database

– 25 stream restoration projects– 10 stream preservation projects– 20 wetland restoration projects– 3 BMP projects

• Step 4: Pollutant removal analysis• Step 5: Stakeholder input – Net Environmental and

Community Benefits Analysis (NECBA)• Step 6: Develop final ranking, Project

Implementation Report, & Project Atlas

Overview of Net Environmental and Community Benefit Analysis

Situations Where MCDA Provides Value

• Complex projects with significant uncertainties

• Numerous potential strategies with multiple decisions

• Multiple stakeholders with competing objectives and different definitions of success

• Potential risks to human health and safety, environment, and reputation

• Significant project costs

• Organizes client intuition

• Reveals insights about trade-offs and cost drivers

• Provides a systematic, transparent, decision-making process

• Helps identify the strategy that best meets client’s goals

• Provides bottom-line cost savings

Benefits of MCDA

Multi-Criteria Decision Analysis

• Capital Budget Priorities for a Port Authority

• Remedial Priorities for Portfolio of 500 Sites for an Oil & Gas Company

• Recreation Priorities for Restoration Projects for State Agencies

• Private Land Use Planning

Examples of Applications

Decision Analysis – Framework

On-Line Survey

On-Line Survey

Framing

Session

Framing

Session

Develop M

odel

Develop M

odel

Prioritize

Projects

Prioritize

Projects

Example Trade-Off Question for On-line Survey

Which alternative is better ?Which alternative is better ?

Alternative A Alternative BImplementation Cost $500,000 $1,000,000

Number of Credits 400 600

Habitat Score 80 60

Probability of Success,Technical Feasibility

75% 50%

A is much better than B

A is better than B

A and B are about the same

B is better than A

B is much better than A

Weights from Trade-Off Questions

0.09

0.16

0.31

0.44

0 0.1 0.2 0.3 0.4 0.5

Credits

Habitat Score

Probability ofSuccess

Cost

Cri

teri

a

Weight

Example of Scoring Calculations

Cost Success Habitat Credits

(0.41 x 25) + (0.29 x 40) + (0.15 x 2)+ (0.08 x 50) = 26.2

Green = Weight

Yellow = Amount of criteria output for an alternative

Comparison of Scores

Project A

Project B

Project C

0 10 20 30 40 50 60

Sensitivity Analysis

Success

Credits

Habitat

Cost

Weight

potential project evaluation and prioritization indian and howard’s creeks local watershed plan...

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