Introduction

Wetlands show moist or saturated surface conditions throughout the year or during parts of it. Mostly linked to groundwater-, stream- or coastal systems, wetlands infiltrate, clean, store, and slowly release water. Wetland types range from upland rain-fed wetlands and wet grasslands to peatlands. They also include coastal and river-fed floodplains. Restoring wetlands is, therefore, closely linked to floodplain restoration (see Measure N.19 ). Due to their capability to store and manage water, wetlands are also measures for surface water management (see Category II).

Benefits & Risks

Highly important for the hydrological cycle, wetlands positively affect the surrounding soils, vegetation, and wildlife. They serve as a natural sponge, which enables them to reduce riverine and pluvial flood volumes. The moist ecosystems can mitigate droughts by slowly releasing water flows during dry periods. Coastal wetlands are buffers from extreme weather events such as storms or waves. Healthy salt marshes, coral reefs, mangroves, or seagrass can play an essential role here. Wetlands, especially peatlands, mangroves, and seagrass, function as highly effective carbon sinks by absorbing and storing greenhouse gases.

On the other hand, draining wetlands causes a massive release of stored CO2. Another critical aspect is that, depending on context and type, wetlands can have less storage capacity and, therefore, even increase water overflows or flooding, such as in the case of the all-year saturated upland rain-fed wetlands. Finally, land use changes and coastal, rural, or urban development may harm and transform the hydrology of the location.

Environmental Impact

Wetlands store great amounts of carbon and have, therefore, a negative CO2 Footprint. In return, the destruction of wetlands can release great amounts of carbon. For example, 10 percent of global carbon emissions result from draining or burning peatlands (Ramsar 2019). 

Good Practice

Originally a natural oasis in a hot and dry desert environment, the Azraq wetland and basin have become the subject of disproportionate water overuse and drilling since 1980. That is especially due to urban expansion and agricultural practice, causing around 25 km2 of wetland to dry up and increasing floods in the area. The wetland lies adjacent to the town of Azraq and the Al-Azraq Refugee Camp, which is home to around 38’000 Syrian refugees.

The massive depletion encouraged the restoration of the wetland in the past 30 years. In 2020, three water pools that had existed earlier in the reserve were rehabilitated. Yet the pools faced an increase in phosphorus rate because non-native fish and algae had become rampant. This made the water inhabitable for endemic species such as the Azraq killifish. Therefore, the three pools were purposely dried out, and their slopes strengthened with topsoil while controlling the bulrush and reeds. Afterward, the small basins were again supplied with water. In addition, the native killifish were reintroduced to the pools, attracting the common kingfisher and other migratory birds.

References

Calow, Roger; Mason, Nathaniel; Tanjangco, Beatrice    (2021):  Nature-based solutionsfor flood mitigation

Mediterranean membership network of wetland managers    (2021):  A success story: restoration of the Azraq Wetland, Jordan

Nova Scotia    (n.d.):  Wetland Compensation - What’s Required and What Are My Options?

Phadtare, Imelda    (2020):  Disaster Risk Reduction and mitigation: green growth in Jordan’s humanitarian sector

Ramsar    (2019):  The key to coping with climate change

Score Card

Criteria

Scale of Intervention

Shelter-Plot-Block Settlement Supra-settlement

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Type of Intervention

Engineered Nature-based Hybrid Non-structural

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Targeted Natural Hazard

Pluvial Flood Coastal/Riverine Flood

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Strategy Type

Relocate Reduce Hazard Magnitude Reduce Asset Vulnerability Reduce Casualties

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Implementation Time

Short (1 day ‐ 1 month) Medium (1 month ‐ 1 year) Long (> 1 year)

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Effect Duration

Short‐term ( <1 year ) Medium‐term (1 year to 10 years) Long‐term (>10 years)

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Targeted Vulnerable Assets

Buildings Transport Technical Infrastructure Land Cover

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Investment Costs

Low Medium High

  Wetland restoration projects di_er in cost depending on their location, landscape, and complexity. Example: A restoration project in Nova Scotia, Canada, describes restoration costs of $3-10 Canadian Dollars per square meter of restored wetland (Nova Scotia n.y.).

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Maintenance Costs (yearly)

Low (<10% investment costs) Medium (10-50%) High (>50%)

Materials

Wood, (Sandy) Soil, Coarse Gravel, Native Vegetation

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