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:

• Make the case to local officials and justify allocation of budget to wetland conservation and restoration programs
• Educate the public about wetland benefits
• Assist with ranking priority sites for wetland conservation and/or restoration
• Estimate the costs associated with loss of wetland functions for wetlands that are highly vulnerable to development impacts
• Estimate the costs associated with historic wetland loss in the community
• Make informed decisions regarding the future use of wetlands by putting wetlands and economic development on a level playing field

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.

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).