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Check-dam cascades in seasonal streams

Check dams are small, low structures built across seasonal streams or ditches to slow down the flow of water. They are often made from rocks, gabions (wire cages filled with stones), sandbags, or logs. Instead of stopping water completely, check dams allow it to pass through slowly. This helps reduce erosion, trap sediments, and give water more time to soak into the ground—recharging groundwater and aquifers. In dry islands like Aruba and Curaçao, where freshwater is limited, this can help manage seasonal droughts.

In places like St. Martin, where heavy rains can cause flash floods and landslides, check dams can reduce the speed and force of runoff, protecting both land and communities. When placed in a series—called a check dam cascade—they are especially effective in slowing water along sloped or degraded landscapes. Check dams are often part of larger water management or ecosystem restoration strategies, such as Managed Aquifer Recharge or Ridge to Reef approaches. By helping to manage both floods and droughts, they contribute to climate resilience and support healthier ecosystems and water supplies for local communities.

Feasibility & Local Applicability

Check dams are relatively low-cost and can be built using locally available materials such as rocks, sandbags, or gabions, making them accessible for small island contexts. However, proper design requires some technical knowledge, including understanding local rainfall patterns, soil types, and stream flow to determine the right size, spacing, and placement of the dams. In small island settings, challenges may include limited technical capacity, fragmented governance, and the need for cross-sector coordination.

Equity & Vulnerability Considerations

To ensure check dams are implemented in an inclusive and equitable way, it’s important to involve local communities from the start. Hiring local contractors and engaging residents in the construction and maintenance of the dams can create jobs and build local ownership. Small-scale farmers, who often rely on seasonal water availability, can be supported or rewarded for their participation. This not only strengthens the long-term success of the project but also ensures that the benefits—like improved water access and reduced flood risk—are shared fairly among those most affected by climate impacts.

Costs

Low- Medium | Costs of check dams depend on the local site conditions, the amount of dams needed and the materials used. Locally sourced materials such as stones or logs can be used, which are usually affordable. Check dams should be maintained regularly, however, the labour needed is minimal.

Case studies & Examples

Literature

Adaptation Options Overview