What is an ordinary watercourse?

Ordinary watercourses are watercourses that are not part of the main river network and that the responsibility lies with the riparian owner. These may be any channel through which water flows such as rivers, streams, ditches, drains or brooks.

Someone who owns a property which is next to a watercourse or has a watercourse flowing through it is called a riparian owner. Under common law, riparian owners have certain rights and responsibilities relating to the watercourse that flows through or alongside their land.

There are over 1200km of known ordinary watercourses in Hertfordshire. This network contributes actively in the flood risk management through the county by its drainage function.

If you are unsure as to whether a particular watercourse is considered an ordinary watercourse, please refer to our online Ordinary Watercourse Map. The map constitutes a representation of the network which may not be exhaustive. If a channel is not mapped, please contact us to ask whether this section is classified as an ordinary watercourse.

SuDS and watercourses team

Call: 01992 588348

Email: ordinarywatercourses@hertfordshire.gov.uk


Works on ordinary watercourses

If you are planning to carry out any works that may affect the flow or storage of water in an ordinary watercourse, you must seek consent from the relevant authority. 

As a Lead Local Flood Authority, Hertfordshire County Council is the regulatory body for works on ordinary watercourses in the county. The ordinary watercourse regulation controls certain activities and works that may obstruct the flow of the watercourse and therefore disrupt its ability to drain areas or transfer water.


The maintenance of an ordinary watercourse lies with the riparian owner. This includes maintenance of the flow within the channel, of its banks and bed and structures on it.

As the Lead Local Flood Authority, we apply the Land Drainage Act 1991 for works on ordinary watercourses. This means we may serve notice on the riparian owner to maintain the flow through the channel.

Consentable works

Any works that directly affect the flow of water in the ordinary watercourse will need our consent following the consent process. This includes any permanent and/or temporary works.

Maintenance works do not require consent.

If you are unsure as to whether you need consent, please contact us to seek advice:

Call: 01992 588348

Email: ordinarywatercourses@hertfordshire.gov.uk



Policies and service standards

The Lead Local Flood Authority has developed a set of policies as a basis of how we will comply with the National Flood Risk Management Strategy within our regulatory role on the ordinary watercourse network.

Please note this policy will be approved as part of the 2017/18 Local Flood Risk Management Strategy review.  

Our ordinary watercourses service standards set out how we carry out the activities related to ordinary watercourses including:

  • Managing the consenting and enforcement activities on ordinary watercourses
  • The timeframes for monitoring and inspecting ordinary watercourses in accordance with their indicative level of flood risk (low, medium or high)
  • The timeframes for responding to any complaints or notifications about an ordinary watercourse (corresponding to its level of flood risk)
  • Performance indicators to be used against the above service areas.