Identifying important barriers in the Hudson River Estuary

Andrew J. Peck, Ph.D.Michelle Brown

Craig Cheeseman

The Nature ConservancyOctober 2012

Project Background

• Aquatic connectivity for streams and rivers is important

• Barriers can be dams, culverts, and natural fall lines

• Thousands of barriers exist in the Hudson River Estuary

How do you know which ones are the most important?

Project Background

• Partners: TNC, NYNHP, DEC-HREP

• Steering committee: TNC, NYNHP, HREP, DEC, DOT

Phase 1 Prioritize barriers Fall 2011

Phase 2 Field assess barriers January – Dec 2012

Phase 3 Prepare final products January – March 2013

Process and Timeline

Model

Components

1. Species

2. Condition

3. Connectivity

Model : Species Component

Partial Species List:

• Diadromous Fish• Brook Trout• Eastern Box Turtle• Comely Shiner• Northern Red

Salamander• Eastern Pond

Mussel

Species –Brook Trout

Species – Eastern Box Turtle

Model: Condition Component

1. Active River Area

2. Impervious Surface

3. Ecoregional Forest Matrix Blocks

4. Priority Tributaries

Condition – Active River Area

Condition – TNC Priority Tributaries

Model: Connectivity Component

Criteria Categories

1. Network Length

2. Absolute Gain

3. Downstream Barriers

Connectivity: Culverts and Dams

Remote Prioritization Results

Prioritization Metric Number of Possible Barriers

Total possible barriers 13,057

Total possible barriers on high condition streams 3,277

Total possible barriers with > 2000m network length 1,677

Total possible barriers with >=750m stream gain 924

Total possible barriers that intersect SGCN models 363

Possible barriers intersecting with SGCN’s that are culverts 283

Possible barriers intersecting with SGCN’s that are dams 80

Field Assessment

• Data Collection Methods– River and Stream Continuity Partnership

www.streamcontinuity.org

• Assessment Protocol– Lake Champlain Basin Fish Passage Initiative

2008- Final report• Juvenile Brook Trout (Salvelinus fontinalis)

– 4 inch difference between bottom of culvert and top of water

– Least common denominator with published data

Field Results: Dams and Culverts

Field Results: Barriers and Non-Barriers

Field Assessment Prioritization

Degree of barrier to passage

+ Degree of habitat impact

Site Score

Prioritization:Tier 1 = 12 – 14

Tier 2 = 9 – 11

Tier 3 = 2 - 8

Barrier Ranking Criteria:

1. Inlet Drop (4 inches)2. Crossing slope matches

stream3. Depth in culvert matches

stream4. Outlet Drop5. Velocity

Impact Ranking Criteria:

1. Relative Scour Pool Size2. Crossing Alignment3. Span Description4. Wetted width (stream vs.

culvert)

Preliminary Results: Priority Barriers

Discussion

• False Negatives– There are probably more barriers out there

• Storm damage reduction aspects, not biodiversity, likely to fuel replacement

• Incorrect notion that FEMA will only replace what was there

Next Steps

• Differentiate between resident and diadromous fish barriers (Fall line layer)

• Develop field application

• Strategic replacement with partners

• DEC Funding Opportunities

Questions