How lined farm ponds guarantee water security

Lined farm ponds are constructed with a barrier or pond liner to prevent water loss and contamination. The liner material used are typically made from reinforced polyethylene (RPE), high density polyethylene (HDPE), or ethylene propylene diene monomer (EPDM). The primary purpose of these farm ponds is to store water for irrigation, livestock watering, and other agricultural uses. The pond liner creates an impermeable barrier, which is essential for retaining water in porous soils and preventing seepage that can lead to groundwater contamination.

Lined ponds are particularly beneficial in regions with sandy or non-clay soils, where traditional clay liners may not be effective. They are also used in conjunction with other water storage solutions, such as roof runoff or yard drainage, to reduce dependence on mains water and promote sustainability.

How common are ponds in the UK?

Ponds and lagoons are becoming more and more common in the UK, particularly in arable, dairy and mixed farming operations. They are used for both water storage and irrigation, depending on the type of farm and system design.

Over the past 20–30 years, lined reservoirs have become increasingly widespread due to rising irrigation demand (especially in eastern and southern England) and more frequent summer droughts. Other possible reasons for the increase in lined ponds is restrictions on summer abstraction from rivers, environmental compliance requirements and government grant schemes supporting on-farm water storage.

They are particularly common in East Anglia, Lincolnshire, Kent, Herefordshire and parts of the Midlands. These regions rely heavily on irrigation for high-value crops such as potatoes, salad crops, onions, soft fruit and field vegetables. In contrast, upland livestock farms are less likely to use lined irrigation reservoirs but may use lined lagoons for slurry containment.

What are these water containment solutions used for?

Most commonly constructed for irrigation water storage primarily on farms in arable regions. Farmers typically abstract water during the winter months (when licences allow higher volumes) and store in a lined reservoir. This water storage solution allows for irrigation during summer when abstraction is restricted. This is now considered best practice in many parts of the UK.

Reservoir sizes vary widely:

• Small farms: 5,000–20,000 m³

• Large arable operations: 100,000 m³ or more

Pond liners such as, EPDM or reinforced geomembranes prevent seepage and ensure compliance with environmental regulations.

In dairy and pig farming, lined slurry and effluent lagoons are used for slurry storage, dirty water and silage effluent.

These are not irrigation reservoirs, but containment systems required under environmental regulations (such as SSAFO rules). They are extremely common across UK livestock farms.

Rainwater harvesting and catchment ponds

Some farms collect roof runoff or yard drainage into lined ponds for irrigation reuse and livestock water. This allows for reduced mains water dependence and is growing in popularity due to sustainability pressures as well as water cost concerns.

Why are pond liners used vs unlined earth ponds?

Historically, some ponds relied on clay soils for sealing however, many UK soils are permeable. Leakage can cause groundwater contamination

Environmental Agency requirements are stricter. High-value water storage makes seepage economically unacceptable. As a result, lined reservoirs are now standard practice for commercial irrigation storage.

The pond liner material needs to be of a quality, robustness and UV resistant to ensure successful water containment integrity.

The trend in the construction of lined farm ponds or reservoirs is upward due to climate change, pressure on abstraction licences, drive for water security, Government encouragement of winter storage and high-value crop production growth.

Many farms now view on-farm reservoirs as essential infrastructure