Field drainage: Designers, contractors and the law

It is important to work with specialists and experts to assess whether to maintain an existing system or create a new one and to consider any legal issues.

Selecting a designer

A new drainage system is a significant investment. It is recommended that independent advice is sought regarding the design.

Before engaging an independent field drainage consultant, make sure they have adequate experience and qualifications.

A specialist and experienced designer will have a thorough understanding of the needs and management of the soils, as well as of field drainage. They will ensure that the scheme is the best and most economically appropriate to meet the requirements.

A designer should:

  • Discuss any site issues and how you intend to manage the site
  • Survey the soil types, soil conditions, existing drainage systems, field topography, proximity to utility services and other features that may affect the final design
  • Consider potential environmental impacts, drainage law and economic feasibility

Selecting a contractor

To install a comprehensive field drainage system, employ a specialist land drainage contractor with access to specialist machinery that can install and backfill drains rapidly.

A drainage machine shapes the trench bed and can set a consistent gradient, even in the flattest of fields.

A specialist contractor should fully understand field drainage requirements and employ the approved standards and materials.

Starting point

The National Association of Agricultural Contractors (NAAC) members are listed on the NAAC website. However, not all drainage contractors are members of the NAAC.

Recommendations from local farmers can be helpful.

Contractors may have different approaches to dealing with the scale, access, and physical aspects of the location. This may lead to a variation in quotes.

Land drainage law

A landowner has an obligation to accept the natural flows of water from adjoining land. They must not cause any impedance to these flows that would negatively affect adjoining land.

Dealing with disputes

If a landowner neglects or fills in their ditch, preventing water from freely discharging from higher neighbouring land, the landowner may be found guilty of causing a nuisance.

Usually, it is best to attempt to resolve situations through amicable discussion (they may be unaware of the nuisance).

However, the landowner or occupier of the higher land may ask the Agricultural Land Tribunal to make an order requiring the landowner guilty of nuisance to carry out the necessary remedial works.


If the neglected ditch runs along a boundary, it is assumed that the owner of the original hedge owns the ditch.

On watercourses, the ownership boundary is assumed to be down the middle of the bed. Only clear evidence to the contrary, such as the deeds to the land, will rebut this assumption.


No ditch or watercourse should be piped, filled in, restricted or diverted without the approval of the regulatory authority. For example, the local authority, the national environmental public body, or the local Internal Drainage Board.

Consent may be needed for works within 8–10 metres of the bank top of a watercourse.

Uncultivated or semi-natural land is protected under the Environmental Impact Assessment Regulations (Agriculture) and should not be drained without prior approval from the relevant national body.

Back to the field drainage home page

Useful links

Read about your responsibilities and rules to follow for watercourses