Small dams, cover and infiltration: strategies to better utilize rainwater.

Adopt Strategies for making better use of rainwater. It is indispensable for farmers seeking to retain soil moisture, combat erosion, and ensure sustainable productivity.

What are small dams and how do they retain runoff?

Small dams are small semicircular excavations built in the ground to intercept rainwater that runs off quickly across the surface of pastures or crops.

How does soil vegetation cover enhance water infiltration?

The mulch deposited on the agricultural surface acts as a protective shield against the direct impact of raindrops, preventing surface soil sealing.

Live roots and decomposing straw create biopores and macropores that function as natural channels for the rapid and uniform descent of accumulated water.

Covered soils maintain mild temperatures, drastically reducing the rate of evaporation and conserving soil moisture for weeks after the local storm has passed.

Crop rotation and diversified green manure strengthen the physical structure of the soil, allowing it to store significant volumes of water exactly where the roots need it.

Technical Comparison of Soil Water Management Agriculture

Water Management Practice	Main Mechanism of Action	Impact on the Infiltration Rate	Estimated Erosion Reduction
Small Retention Dams	Capture and infiltration of runoff	High-volume spot retention	High sediment retention
Straw and Mulch	Physical protection against water impact	Continuous increase through biopores	Reduction of more than eighty percent
Contour Lines (Terracing)	Slowing of surface flow	Fractional absorption along the slope	Prevention of gullies and ravines
Bare soil and plowed	Direct exposure and mechanical sealing	Low capacity due to compaction.	High risk of topsoil loss

Why is the combination of contour lines and small dams efficient?

Terracing along contour lines cuts across the slope of the land, dividing the force of the water into short sections that reduce the erosive capacity of the rain.

By directing excess water from bends to strategically located small dams, the producer eliminates the destructive accumulation of runoff on the property's internal roads.

This synergy prevents the loss of valuable nutrients from the topsoil layer, preserving organic matter and applied inputs in the cultivated area.

Access the technical guidelines and research on soil and water conservation published by Embrapa to plan physical interventions on your property.

When should the water conservation plan be implemented on the property?

The ideal time to plan and execute earthmoving works, such as small dams and terraces, is during the dry season, when the soil is firm.

Building the structures before the first rains begin ensures that the ground is ready to capture the initial rainfall without suffering breaches.

Find out more: Rainwater harvesting system: see how to do it!

Sowing cover crops as soon as the first rains arrive accelerates germination and quickly protects the soil before the most intense storms of the rainy season.

Execute the Strategies for making better use of rainwater. Timely implementation ensures the full functioning of the infrastructure and maximizes absorption within the target profile.

What precautions are necessary when maintaining retention basins?

Regularly inspecting the slopes and bottom of small dams prevents excessive clogging by sediments and ensures full volumetric capacity throughout the year.

Removing excess soil accumulated at the bottom of the basin returns this nutrient-rich material to the planting areas as natural fertilizer.

Maintaining low-lying vegetation at the edges of excavations stabilizes the earthen walls, preventing internal collapses caused by the turbulent influx of impounded water.

Consult the collection of technical publications and rural extension bulletins made available by Ministry of Agriculture and Livestock for guidance on sustainable management.

Frequently Asked Questions (FAQ)

Can small dams allow dengue mosquitoes to accumulate on properties?

No, because the stored water percolates into the subsoil in up to 48 hours, which is insufficient time for the hatching and development of insect larvae.

What should be the average depth for constructing a small dam?

The standard depth varies between 1.5 and 2 meters, with the diameter adjusted according to the slope and runoff volume of the area.

Does mulch on the soil hinder the emergence of planted seeds?

No, as long as the seeder is properly adjusted to cut through the straw and deposit the seed at the correct depth in the moist soil.

Is an environmental permit required to construct stormwater retention basins?

Generally, small-scale stormwater retention basins for soil conservation do not require complex licensing, but consult your local authority.

Adopt Strategies for making better use of rainwater. It consolidates a resilient, productive, and ecologically sound agriculture. Combining small dams, vegetation cover, and contour lines protects the soil, recharges aquifers, and ensures the water security of your production.

Written by Izabelle

I've been a content strategist for over 4 years, helping brands transform technical topics into meaningful content for their readers. Throughout this time, I've worked in various niches, always combining SEO, audience behavior, and trends to create content that generates genuine connection, not just reach. I like to think that good content is content that explains, connects, and makes reading easy, without losing sight of the underlying intention.

Updated on September 2, 2026

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