land conservation strategies- jeff hartranft

Jeffrey Hartranft

Bureau of Waterways Engineering and Wetlands

Division of Wetlands Encroachments and Training

Legacy Sediment Problems in Pennsylvania

What to do about those dammed eroding streams?

Department of Environmental Protection

Pennsylvania

Pennsylvania Legacy Sediment Workgroup

Presentation Outline

• Legacy Sediment Examples and Definition

• A New Best Management Practice to Address the Problem

• Big Spring Run Demonstration Project

• Aquatic Resource Restoration Potential

Photos Courtesy Franklin & Marshall College

Big Beaver Creek – Lancaster County, PA

Conoy Creek – Lancaster County, PA

Mountain Creek - Cumberland County, PA

Photo Courtesy Franklin & Marshall College

Seneca Creek, Maryland

Impact of Water-Powered Mills on Sediment Storage

New dam

Courtesy Franklin & Marshall College

Natural Wetland SoilsNatural Wetland Soils

Legacy SedimentModern Substrate

GroundwaterGroundwater

Riparian Zone

GroundwaterGroundwater

DEPARTMENT OF ENVIRONMENTAL PROTECTION

Typical Mill Dam and Valley Cross Section

Time 1Time 2

Gravel

Colluvium

UplandSoil

BedrockGravel

Bedrock

Colluvium

UplandSoil

Riparian Zone

DEPARTMENT OF ENVIRONMENTAL PROTECTION

Typical Valley Cross Section Evolution

Time 1Time 2 - Dam Breached

Gravel GravelGroundwaterGroundwater

Natural Wetland Soils Natural Wetland Soils

Modern Substrates

Bedrock BedrockGroundwater

Colluvium

Groundwater

UplandSoil

UplandSoil Legacy Sediment Legacy Sediment

Colluvium

Time 3 - Dam Breached

More than 65,000 waterpowered mills existed along U.S. streams in the year 1840. The greatest density of mills occurred in the Piedmont and Ridge and Valley

physiographic province.

Mill density map based on the 1840 US Census and county boundaries.

http://www.depweb.state.pa.us/chesapeake

http://www.depweb.state.pa.us/chesapeake

Dam Locations from 1860-1870 Era Atlases

Photos Courtesy Franklin & Marshall College

http://www.depweb.state.pa.us/chesapeake

Natural Streams and the Legacy of Water-Powered

Mills

January 18, 2008 pp. 299-304

Robert C. Walter and Dorothy J. Merritts

Franklin & Marshall CollegeLancaster, PA

Conventional wisdom

GravelBase Flow

Rural&

Agriculture

Sub-Urban

&Urban

GravelGroundwaterGroundwater

GroundwaterGroundwater

Bedrock Bedrock

Natural Wetland Soils Natural Wetland Soils

Riparian Zones With Incised Channels

Riparian Zone

Flood Flow

• Bank Trampling • Upland Soil Erosion• Few Trees / Shrubs• Manure

• Stormwater• Impervious surfaces • Few Trees / Shrubs• Wastewater discharges

Legacy SedimentLegacy Sediment

DEPARTMENT OF ENVIRONMENTAL PROTECTION

~300 - ~10,000 BP (14C)

1850 AD (210PB)

• Streambanks represent a significant sediment and nutrient source in watersheds where channels have incised through legacy sediment. (Walter, Merritts, Rahnis, 2007; 2010)

• Legacy sediment stored in valley bottoms predominantly was established by the combined effect of increased sediment supply from uplands and sediment trapping behind ubiquitous dams in many watersheds of the mid-Atlantic Region. (Walter and Merritts, 2008)

Typical Existing Condition

Flood Flow

Legacy Sediment

Bedrock

Gravel

Base Flow Hydric Soils

Existing Root Zone

Bank-full Flow

Modern, inset bar

Hydric Paleosol

• Conceptual models linking channel condition and sediment yield exclusively with modern upland landuses are incomplete for valleys impacted by mill dams (Merritts, et al. 2011)

Big Spring Run - Type Section

Courtesy Franklin & Marshall College

Ecological Restoration Guiding Principles

Address ongoing causes of degradation.

• Restoration efforts are likely to fail if the sources of degradation persist.

• It is essential to correctly identify the causes of degradation and eliminate or remediate them.

• Understanding a stream’s evolutionary trajectory is relevant to correctly diagnosing the problem, as well as to developing restoration approaches that are likely to be sustainable.

“… understanding the legacy sediment problem is the first step in proposing a fix.”

Bay Journal, March, 2007. Alliance for the Chesapeake Bay.

Proposed Restoration

Natural Valley Morphology

Conceptual Design

Typical Existing Conditions

Natural Floodplain, Stream and Riparian Wetland Restoration Best Management Practice

Bedrock

Gravel

Root Zone

Flood Flow

Bank-full Flow

Base FlowRestored Hydric Paleosol

Flood Flow

Legacy Sediment

Bedrock

Gravel

Base Flow Hydric Soils

Existing Root Zone

Bank-full Flow

Modern, inset bar

Hydric Paleosol

Photos Courtesy Franklin & Marshall College

Typical Existing Conditions

Natural ValleyMorphology

9/13/2011

Restoration9/23/2011

Flow Direction

2007 Banta Restoration Site, Lititz Run – Lancaster Co.

Photo Courtesy Franklin & Marshall College

2007 Banta Restoration Site, Lititz Run – Lancaster Co.

Photo Courtesy Franklin & Marshall College

2007 Banta Restoration Site, Lititz Run – Lancaster Co.

2011 Banta Restoration Site, Lititz Run – Lancaster Co.

Big Spring Run Natural Floodplain, Stream and Riparian Wetland Restoration Project

We have assembled a multidisciplinary team of biologists, ecologists, engineers, geomorphologists, geochemists, landowners, restoration practitioners, and construction experts (Hartranft et al,

2011).

USGS 015765195 Big Spring Run near Mylin Corners, PA

Big Spring Run ca. 1930Photo Courtesy Franklin & Marshall College

Funding Partners

PA Department of Environmental Protection

Franklin & Marshall College

US Environmental Protection Agency

US Geological Survey

Joseph V. Sweeney

Chesapeake Bay Commission

Foundation for Pennsylvania Watersheds

PA Fish and Boat Commission

Lancaster Farmland Trust

Monitoring and Research Partners

Big Spring Run ca. 1930

Franklin and Marshall College

US Geological Survey

US Environmental Protection Agency (ORD & Region III)

PA Department of Environmental Protection

PA Fish and Boat Commission

Johns Hopkins University

Elizabethtown College

Penn State University

Photo Courtesy Franklin & Marshall College

Legacy Sediment Workgroup Collaborator Organizations and Individuals

PA Department of Environmental ProtectionPA Fish and Boat Commission PA Department of Transportation US Environmental Protection AgencyUS Geological SurveyChesapeake Bay CommissionPennsylvania Environmental CouncilFranklin and Marshall CollegePenn State UniversityLafayette CollegeLandstudies Inc.Rettew and AssociatesCDMChesapeake Bay FoundationPA Farm BureauAmerican RiversPA State Association of Township SupervisorsJoseph Sweeney