Wetlands quietly clean up pollution – and save communities millions – Earth.com

Report on the Efficacy of Restored Wetlands in Achieving Sustainable Development Goals

Introduction: Wetlands as a Nature-Based Solution for Global Goals

Recent research highlights the critical role of restored wetlands in advancing several United Nations Sustainable Development Goals (SDGs). By functioning as natural filters for agricultural runoff, these ecosystems provide significant environmental and economic benefits. This report analyzes the findings of a study conducted in the Mississippi River Basin, focusing on the contributions of wetland restoration to water quality, ecosystem health, and community sustainability.

• SDG 6 (Clean Water and Sanitation): Wetlands directly improve water quality by removing pollutants.
• SDG 14 (Life Below Water): By reducing land-based nutrient pollution, wetlands protect downstream aquatic and marine ecosystems from eutrophication and harmful algae blooms.
• SDG 15 (Life on Land): The restoration of wetland habitats is fundamental to protecting and restoring freshwater ecosystems and their biodiversity.
• SDG 11 (Sustainable Cities and Communities): The natural water purification services provided by wetlands create significant economic savings for public water systems, enhancing urban and community resilience.

Key Research Findings on Water Quality and Ecosystem Restoration

Quantitative Impact on Nutrient Pollution (SDG 6 & SDG 14)

A long-term study conducted by the University of Illinois Urbana-Champaign and Montana State University assessed the impact of restored wetlands on water quality from 1990 to 2018. The research focused on wetlands created through a federal program that converted retired farmland back to its natural state.

1. Scope of Study: The analysis covered approximately 9,000 permanent wetland easements, constituting just 0.22% of the Mississippi River Basin’s land area.
2. Nitrogen Reduction Mechanism: Wetlands effectively remove nitrogen from water through denitrification, a process that converts harmful nitrates into harmless nitrogen gas (N₂).
3. Measurable Improvements: Within three years of restoration, the wetlands demonstrated significant reductions in key nitrogen compounds.
   • Ammonia levels were reduced by 62%, equivalent to a decrease of 0.08 milligrams per liter.
   • Total Kjeldahl Nitrogen (TKN) was reduced by 37%, equivalent to a decrease of 0.20 milligrams per liter.

Ecosystem Resilience and Restoration (SDG 15)

The study confirmed that restored wetlands are highly effective, particularly in areas most affected by agricultural pollution. This demonstrates their resilience and importance as a tool for targeted environmental restoration.

• High-Impact Performance: Contrary to concerns that wetlands might become overwhelmed by high nutrient loads, the research found they perform exceptionally well in heavily polluted waters.
• Contribution to Biodiversity: The restoration of these areas contributes directly to SDG Target 15.1, which calls for the conservation and restoration of inland freshwater ecosystems and their services.
• Phosphorus Impact: The study noted a less consistent long-term impact on phosphorus levels, indicating an area for further research in optimizing wetland restoration for multiple pollutants.

Economic and Social Implications for Sustainable Communities

Cost Savings and Sustainable Infrastructure (SDG 11)

The water purification services provided by wetlands translate into direct and substantial economic benefits for local communities, aligning with the goal of building sustainable and resilient infrastructure.

• Reduced Water Treatment Costs: By naturally lowering nitrogen levels, wetlands reduce the financial burden on public water systems required to meet federal safety standards.
• Projected Financial Gains:
  • The restoration of just 100 acres of wetland can save a large public water system up to $17,000 annually.
  • Across the entire Mississippi River Basin, the cumulative annual savings for local governments could reach as high as $200 million.
• Effective Cost-Transfer Model: Federal investment in wetland restoration programs results in direct financial savings for local communities, representing a successful partnership model for achieving environmental and economic goals.

Policy Challenges and Recommendations for Future Action

Threats to Wetland Protection and SDG Progress

Despite their proven benefits, the legal protection for many wetlands is under threat. A recent Supreme Court decision narrowed the scope of the Clean Water Act, potentially jeopardizing the continued provision of these vital ecosystem services.

• Regulatory Gaps: The ruling limits federal protection to wetlands directly adjacent to navigable waters, placing a significant percentage of inland wetlands at risk. In Illinois, for example, 72% of wetlands could lose protection.
• Risk to SDG Achievement: The loss of these ecosystems would reverse progress on water quality (SDG 6), ecosystem health (SDG 14 & 15), and community economic stability (SDG 11).

A Path Forward for Integrated Conservation (SDG 17)

The study’s findings provide a strong evidence base for policymakers to strengthen wetland protection and integrate them into broader environmental strategies.

1. Strengthen Policy and Protection: The demonstrated economic and environmental value of wetlands should inform policy decisions aimed at protecting all wetlands, regardless of their proximity to navigable waters.
2. Promote Integrated Strategies: Wetlands should be utilized in tandem with other nutrient reduction strategies, such as cover crops and buffer strips, to create a comprehensive approach to sustainable agriculture and water management.
3. Foster Partnerships: Continued collaboration between federal and local governments, research institutions, and private landowners is essential for scaling up conservation efforts and achieving the Sustainable Development Goals.

1. Which SDGs are addressed or connected to the issues highlighted in the article?

SDG 6: Clean Water and Sanitation

• The article’s primary focus is on how restored wetlands improve water quality by filtering nitrogen pollution from agricultural runoff in the Mississippi River Basin. This directly addresses the goal of ensuring the availability and sustainable management of water and sanitation for all.

SDG 14: Life Below Water

• The article explains that nutrient runoff from farms can “trigger algae blooms, harm fish, and even contaminate drinking water.” By reducing nitrogen pollution that flows through the Mississippi River Basin, which ultimately drains into the Gulf of Mexico, the restoration of wetlands helps mitigate land-based pollution affecting marine ecosystems.

SDG 15: Life on Land

• The entire article is about the benefits of restoring wetland ecosystems. It discusses a federal program that pays landowners to “retire farmland and let those areas return to wetland.” This directly relates to protecting, restoring, and promoting the sustainable use of terrestrial ecosystems.

SDG 11: Sustainable Cities and Communities

• The article highlights the economic benefits for local communities, stating that wetlands “are also saving local governments a lot of money.” It quantifies these savings in water treatment costs, which contributes to the financial and environmental sustainability of cities and public water systems. The article also mentions that wetlands “reduce flooding,” which is a key aspect of making communities more resilient to water-related disasters.

2. What specific targets under those SDGs can be identified based on the article’s content?

SDG 6: Clean Water and Sanitation

• Target 6.3: By 2030, improve water quality by reducing pollution. The article directly addresses this by detailing how wetlands reduce nitrogen pollution from agricultural runoff. The study shows wetlands “are doing a solid job cutting down nitrogen pollution.”
• Target 6.6: By 2020, protect and restore water-related ecosystems, including wetlands. The article’s subject is a program that creates “permanent wetland easements” and restores these ecosystems, demonstrating a direct link to this target.

SDG 14: Life Below Water

• Target 14.1: By 2025, prevent and significantly reduce marine pollution of all kinds, in particular from land-based activities, including nutrient pollution. The article focuses on reducing nitrogen, a form of nutrient pollution from land-based agriculture, which flows downstream and impacts larger bodies of water.

SDG 15: Life on Land

• Target 15.1: By 2020, ensure the conservation, restoration and sustainable use of terrestrial and inland freshwater ecosystems and their services, in particular wetlands. The article is a case study of wetland restoration and the valuable ecosystem service they provide (water filtration).

SDG 11: Sustainable Cities and Communities

• Target 11.5: By 2030, significantly reduce… direct economic losses… caused by disasters, including water-related disasters. The article explicitly states that wetlands “reduce flooding,” which aligns with mitigating the impact of water-related disasters on communities.
• Target 11.b: By 2020, substantially increase the number of cities and human settlements adopting and implementing integrated policies and plans towards… resource efficiency… [and] disaster risk reduction. The use of wetlands as a natural, cost-effective solution for water treatment and flood control is an example of such an integrated plan, saving cities money and enhancing resilience.

3. Are there any indicators mentioned or implied in the article that can be used to measure progress towards the identified targets?

Indicators for Water Quality Improvement (Target 6.3)

• Percentage reduction in pollutants: The article states that “restored wetlands lowered ammonia levels by 62% and total Kjeldahl nitrogen (TKN) by 37%.”
• Change in concentration of pollutants: The article quantifies the improvement as “a reduction of 0.08 milligrams per liter for ammonia and 0.20 milligrams per liter for TKN.”

Indicators for Ecosystem Restoration (Targets 6.6 & 15.1)

• Area of restored ecosystems: The article mentions that “From 1990 to 2018, around 9,000 permanent wetland easements were added to the Mississippi River Basin.” The total acreage of these easements serves as a direct indicator of restoration progress.

Indicators for Economic Benefits and Resilience (Targets 11.5 & 11.b)

• Cost savings in public services: The article provides a clear economic indicator: “restoring just 100 acres of wetland in a small watershed could save large public water systems up to $17,000 a year in treatment costs.”
• Total economic value of ecosystem services: The article estimates the total regional savings, stating that “these wetlands could help local governments save as much as $200 million every year.” This figure measures the overall economic benefit provided by the restored wetlands.

4. Table of SDGs, Targets, and Indicators

Source: earth.com