Home 4. Estimate Wetland Values

Estimate Wetland Values

Wetlands provide an abundance of valuable functions and services, including flood storage, wildlife habitat, pollutant removal, recreation and commercial products.  These “free” services are often taken for granted and can be difficult (if not impossible) as well as very expensive to replace, as wetlands are altered or degraded in a watershed. 

Despite the expense and uncertainty associated with replacing the lost ecological services of wetlands, urban and rural development, which accounted for 61% of wetland losses during 1998-2004 (Dahl, 2006), continues to impact wetlands.  Preventing the loss of wetland functions is a challenge, particularly when financial gains for individual parcel development seemingly outweigh non-market wetland values for the greater community. To address this concern, scientists have begun to assign economic values to the important roles of wetlands. This is done through a process known as economic valuation that aims to make ecosystem goods and services directly comparable to other sectors of the economy. Some examples include:

  • Constanza (1997) estimated the global value of wetland ecosystems at $14.9 trillion
  • In a recent study by NJ DEP (2007), wetland services in NJ were valued at $9.4 billion per year for freshwater wetlands and $1.2 billion per year for saltwater wetlands.

Placing an economic value on wetland functions and services may serve as a useful tool to help a community justify wetland protection.   Wetland valuation may be particularly useful in communities where wetlands are still viewed as nuisance features or mosquito havens. The data generated from a wetland valuation study can be used to:

Economic valuation studies can be costly and will likely require assistance from an environmental economist.  If this is not an option for your community, readily available economic data from local sources or existing studies may be sufficient to begin educating decisions makers about the true value of wetlands and cost to replace their services.  Table 4.1 lists some of the replacement options for lost wetland services that communities can begin to put a price on using up-to-date and local cost data. If data from scientific studies are beneficial to local decision-makers, Table 4.2 presents some values for different wetland types from two major wetland valuation studies. These values represent the cost incurred from wetland mitigation projects to restore wetlands and do not represent the cost to replace a wetland.  These costs are used by state and federal regulators as a threshold for the costs to replace lost wetland services and values. Additional wetland valuation studies can be found in the GecoServ Gulf of Mexico Ecosystem Services Valuation Database developed by the Harte Research Institute for Gulf of Mexico Studies at the Texas A&M University.

Table 4.1. Replacement Options for Wetland Services

Wetland Services

Replacement Options

Flood protection

Stormwater treatment practices (storage); dikes and levees; advanced floodplain construction design

Recreation

Wetland restoration; species stocking

Maintain drinking water quality

Water filtration plants, develop new water source

Shoreline property protection

Revetments; stream bank stabilization and repair practices; stormwater treatment practices for channel protection

Maintain baseflow in streams

Deeper wells; alternative water source

Wildlife habitat and biodiversity

Wetland restoration; species stocking

Commercial products from wetlands (e.g., peat, timber, cranberries, rice, fish, shellfish)

Wetland restoration

Reduce pollutants in streams and stormwater

Stormwater facilities designed to meet water quality criteria (WQv)

 

Table 4.2.  Wetland Values

Study #1: King and Bohlen, 1994

Study #2: Louis Berger and Associates, Inc., 1997

Wetland Type

1997 $ Cost/Acre

Wetland Type

1997 $ Cost/Acre

Aquatic bed

$45,000

Emergent

$43,675

Complex

$95,000

Scrub/Shrub

$124,144

Freshwater mixed

$52,000

Intertidal emergent

$415,007

Freshwater forested

$124,000

Open water – emergent

$273,700

Freshwater emergent

$84,000

Open water – shrub/forest

$130,220

Freshwater tidal

$78,000

Emergent scrub/shrub

$351,591

Salt marshes

$49,000

Emergent/intertidal

$59,238

Mangroves

$24,000

Emergent – forested

$235,799

Prairie potholes

$4,000

Riverine emergent

$82,928

Other agricultural

Less than $1,000

 

 

These numbers do not reflect the full cost of restoring wetland services or the full value of wetland services. The numbers represent how much money U.S. state and federal agencies have spent to attempt to restore wetland services.  The numbers include pre-construction, construction, and post-construction tasks but they do not include the time and resources of government agencies.  Numbers were not adjusted to account for significant failure rates for restoration or delays in wetland recovery after restoration (King, 1998).

Estimating Values Provided by Wetlands in Your Community provides the general process of conducting a wetland valuation study.  For more detail on this process, refer to An Integrated Wetland Assessment Toolkit. For general information on ecosystem valuation refer to www.ecosystemvaluation.org
 

CASE STUDY - New Jersey Natural Resource Valuation Study

The New Jersey Department of Environmental Protection (NJ DEP) worked with researchers from the University of Vermont to be the first state to assess the economic value of all of New Jersey’s natural resources. 

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Resources for Estimating Wetland Values

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Digitize
The process of converting features on a paper map into digital format using a trace methodology, which results in the creation of a spatial dataset.
Ecotone

A transition area between two adjacent, but different plant communities.

Indirect Wetland Impacts
Impact to wetlands caused by inputs of stormwater and pollutants generated by land development or other activities within the wetland CDA.
Direct Wetland Impacts
Wetland loss or degradation resulting from activities that occur within wetlands, such as dredging, filling and draining.  Activities that cause direct impacts are largely regulated through the federal and state wetland permitting process.
Stormwater Treatment Practices

A structural or non-structural practice designed to temporarily store or treat stormwater runoff in order to mitigate flooding, reduce pollution, and provide other amenities (also called a Best Management Practice – BMP).

Hydrogeomorphic
Factors that influence how wetlands function, including geomorphic setting, water source, and hydrodynamics.
Hydrogeomorphic
Factors that influence how wetlands function, including geomorphic setting, water source, and hydrodynamics.
Sinks
A cell or set of spatially connected cells that cannot be assigned flow direction in a raster elevation dataset. This can occur when all neighboring cells are higher than the processing cell or when two cells flow into one another. Sinks can indicate areas where water is likely to pond, but can also be an error in the dataset.
Facultative Wetland Plants
Species that usually occur in wetlands (approximately 67% - 99% probability), but also occur in non-wetland areas (approximately 1% - 33% probability).
Obligate Wetland Plants
Species that occur almost always in wetlands under natural conditions (greater than 99% probability), but which may also occur rarely in non-wetlands (less than 1% probability).
Interferometric Synthetic Aperture Radar (IFSAR)
A radar technique that uses two or more synthetic aperture radar (SAR) images to generate surface elevation using differences in the phase of waves returning to the satellite or aircraft.
Interferometric Synthetic Aperture Radar (IFSAR)
A radar technique that uses two or more synthetic aperture radar (SAR) images to generate surface elevation using differences in the phase of waves returning to the satellite or aircraft.
Light Detection and Ranging (LiDAR)

A remote sensing technique that measures properties of pulsed laser light reflected from objects to determine their position, velocity, and other information.

Light Detection and Ranging (LiDAR)

A remote sensing technique that measures properties of pulsed laser light reflected from objects to determine their position, velocity, and other information.

Light Detection and Ranging (LiDAR)

A remote sensing technique that measures properties of pulsed laser light reflected from objects to determine their position, velocity, and other information.

Digital Elevation Model (DEM)
A digital file consisting of terrain elevations for ground positions at regularly spaced horizontal intervals.
Digital Elevation Model (DEM)
A digital file consisting of terrain elevations for ground positions at regularly spaced horizontal intervals.
Hyperspectral Data

Information collected and processed from across the electromagnetic spectrum. Spectral signatures (unique “fingerprint” left by specific objects) enable identification of materials that make up a scanned object.

Remote Sensing
Gathering and recording information about objects without actual contact through the use of such techniques as photography, infra-red imagery, and radar.
Hydrophytes
A plant that grows wholly or partially submerged in water.
Blackspots
Areas on aerial photos that show up as dark blue, dark grey, or black and are indicative of saturated soil conditions.
Stereoscopic
The ability to see three dimensionally by using two views of a single object from slightly different positions typically through the use of an optical aid known as a stereoscope.
Hydric Soils
Soils that are saturated, flooded, or ponded for a long enough period during the growing season to develop anaerobic conditions in the upper soil horizons.
Hydric Soils
Soils that are saturated, flooded, or ponded for a long enough period during the growing season to develop anaerobic conditions in the upper soil horizons.
Hydric Soils
Soils that are saturated, flooded, or ponded for a long enough period during the growing season to develop anaerobic conditions in the upper soil horizons.
Hydric Soils
Soils that are saturated, flooded, or ponded for a long enough period during the growing season to develop anaerobic conditions in the upper soil horizons.
Hydric Soils
Soils that are saturated, flooded, or ponded for a long enough period during the growing season to develop anaerobic conditions in the upper soil horizons.
Hydric Soils
Soils that are saturated, flooded, or ponded for a long enough period during the growing season to develop anaerobic conditions in the upper soil horizons.
Hydric Soils
Soils that are saturated, flooded, or ponded for a long enough period during the growing season to develop anaerobic conditions in the upper soil horizons.
Hydric Soils
Soils that are saturated, flooded, or ponded for a long enough period during the growing season to develop anaerobic conditions in the upper soil horizons.
Geographic Information Systems (GIS)

A system that integrates hardware, software, and data for capturing, managing, analyzing, and displaying all forms of geographically referenced information.

Geographic Information Systems (GIS)

A system that integrates hardware, software, and data for capturing, managing, analyzing, and displaying all forms of geographically referenced information.

Digitize
The process of converting features on a paper map into digital format using a trace methodology, which results in the creation of a spatial dataset.
Minimum Mapping Unit

The minimum size or dimensions for features to be mapped as lines or areas for a given map scale.