Riparian Ownership
Riparian Ownership and Legal Obligations
A riparian owner is a landowner whose property adjoins or is intersected by a natural watercourse (rivers, streams, ditches, culverts, etc.). By common law the ad medium filum aquae presumption applies to non-tidal waters: the owner of land bounded by a river or stream is assumed to own the bed of the channel to its centre line. (Tidal rivers are treated differently: the Crown generally owns the foreshore up to mean high-water mark.) Riparian owners acquire certain rights (for example, to receive water flow, to fish with a licence and abstract limited domestic water) but also bear strict obligations. These obligations are rooted in both statute and common law, and aim to prevent flooding or pollution of adjoining land. Key riparian duties include:
Key Riparian Responsibilities
Maintaining the watercourse. The riparian owner must keep the bank and bed of the stream (or ditch) clear and in good order, including removing debris, fallen trees or blockages. Any obstruction that impedes flow may give rise to liability.
Ensuring free flow of water. Water must be allowed to flow “naturally” through the watercourse. A riparian owner must accept and carry away the flow coming from upstream, even if the downstream channels are inadequate (provided one has done nothing unreasonable to cause flooding). Significantly, under the Land Drainage Act 1991 an owner must maintain the watercourse so that “the free flow of water is not impeded”, and this includes even culverted or buried drains.
No pollution or nuisance. The owner must keep the water free from contamination or noxious substances. Discharging waste, chemicals or soil run-off into the watercourse is prohibited by statute; heavily polluted water is a statutory nuisance under the Environmental Protection Act 1990, for which local authorities can require abatement. In practice, riparian owners must prevent pollution of the stream and remove obstructions or invasive species that could foul the water.
Licences and consents for works. No one may alter or work on a watercourse without consent. A riparian owner who wishes to build or modify any structure in or alongside the stream (for example, a weir, culvert, bridge, dock or bank) must first obtain any necessary permission or licences from the Environment Agency or lead local flood authority. Doing unconsented work can incur fines or even criminal sanctions. In particular, one must seek a land drainage consent (often from the local authority) before culverting or diverting water.
Reporting and co-operation. Riparian owners should report incidents (flooding, breaches or pollution) to the authorities and co-operate with risk management. They should also tolerate any legal flood-avoidance works carried out by the Environment Agency or Internal Drainage Board on their land in emergencies, which statutory bodies may do and then seek cost recovery.
In short, riparian owners must not worsen flood risks or neglect the watercourse. The common law reinforces these duties, for example, the courts have long held that a riparian owner “owes a duty to keep the bed of his stream clear” to avoid flooding neighbours. Historically in Gerrard v Crowe (1921) an owner was even allowed to raise his own banks to defend against flooding (though
Statutory Controls: LDA 1991, EPA 1990 and More
The riparian regime is governed by a mix of statute and common law:
Land Drainage Act 1991 (LDA 1991): Consolidating earlier drainage laws, the LDA 1991 imposes explicit duties on landowners. Notably, s.72 and related provisions require that a watercourse be kept clear so that the free flow of water is not obstructed. Local authorities also have powers to serve drainage maintenance notices if riparian owners fail to keep channels open. The Act requires landowners to apply for ordinary watercourse consents before performing most works (culverting, bank strengthening, etc.) on any stream. In short, the LDA 1991 makes it a statutory duty to maintain drainage and prevent flooding on riparian land.
Environmental Protection Act 1990 (EPA 1990): Part III of EPA 1990 creates statutory nuisances including polluted water. Any watercourse “in such a state as to be prejudicial to health or a nuisance” (e.g. carrying sewage or toxic discharge) can be declared a nuisance, compelling local authorities to require clean-up or risk abatement orders. A riparian owner therefore has a duty to avoid discharging wastes into the stream and generally to comply with pollution control laws. (More broadly, the Water Resources Act 1991 governs discharges to water, e.g. one needs EA permits to discharge trade effluent, but that is usually dealt with in environmental licensing regimes.)
Flood and Water Management Act 2010: This Act reformed local flood risk management by making Lead Local Flood Authorities (county councils or unitaries) responsible for ordinary watercourses and sustainable drainage systems (SUDS) in new developments. It bolstered the powers of risk management authorities but did not remove riparian obligations. One new feature is that SUDS approval bodies (usually LLFAs) can require surface water drainage schemes on new sites, which interact with riparian rights if flows are connected to natural watercourses.
In addition, general property law applies: for example, no one can assert a right to divert another’s water so as to harm them, and Victorian statutes (like the Public Health Acts) also touch on drainage. But the LDA and EPA remain the principal statutory controls. Together with common-law nuisance and negligence principles, they create a comprehensive framework: riparian owners must not obstruct or pollute the course of water and must take reasonable care not to let water damage others.
Conveyancing Due Diligence
For conveyancers acting in England and Wales, properties adjoining watercourses require special attention. Good practice is to treat flood risk and riparian issues as material. In particular:
Standard Searches and Risk Enquiries
- Title and boundary checks: Examine the registered title and plan carefully. The Land Registry does not automatically include watercourses within a title, even if they flow through or alongside the land. If a river forms the boundary, the owner is presumed to own to the centre (ad medium filum), but this may not appear on the register unless specifically claimed. Lawyers should verify whether any riparian rights or covenants are noted. Applications to include a watercourse in a title can be made, but typically they require evidence (title plans, historical conveyances). It is therefore vital to “know your boundaries” and to clarify which party is responsible for each stretch of the stream.
- Standard searches: In addition to the usual Office Copy Entries, solicitors should order Local Authority searches that include Land Drainage or Water Authority information. Many conveyancing packages now include a Drainage and Water Search (or Con29DW) which reveals water mains, sewers and watercourses. A specific Land Drainage Search or enquiry (sometimes via the Lead Local Flood Authority or Internal Drainage Board) will indicate whether the watercourse is a classified river and whether consents have been issued. The Law Society’s flood-risk practice note (2020) advises solicitors to carry out thorough flood searches, to review Environment Agency flood maps and to ask relevant enquiries of the seller and authorities.
- Seller and specialist enquiries: Conveyancers should raise enquiries on whether the property has ever flooded, and if there are any defences (e.g. levees) or drainage maintenance responsibilities. Under standard conveyancing practice, the seller’s replies (and the Water and Drainage Questionnaire) should disclose any knowledge of water seepage or past flooding. If a culvert or pipe runs under the property, the Land Drainage Act makes the owner liable for its upkeep (even if buried), so this should be confirmed. In some cases it may be prudent to commission an independent flood-risk report or consult the local flood authority for any known issues.
Insurance considerations: Clients should be advised to check that the proposed purchaser’s buildings insurance covers flood risk. Many insurers request flood searches or charge higher premiums in flood-prone areas; the UK’s Flood Re scheme (a joint government-insurer fund) offers affordable cover for qualifying homes at risk. Conveyancers should note this as part of advising on a property that is near a watercourse or in a flood zone.
As the RICS consumer guide to flooding warns, a solicitor’s desktop search cannot substitute for actual inspection and professional advice. In practice, solicitors and surveyors should communicate: if the title search or site inspection reveals a stream or culvert, the seller should be queried and the buyer should be apprised of the riparian implications. Proper due diligence is essential – failure to spot and advise on riparian obligations can have serious consequences (for example, a buyer who later incurs flood damage may blame their advisers for failing to warn).
Surveyors’ Duties and Professional Liability
Where a surveyor is instructed (for example, to carry out a building survey or HomeBuyer Report), they have a professional duty to exercise reasonable skill and care for the client.
Surveyor’s Flood Inspections and RICS Duties
RICS standards underpin this duty. A chartered surveyor is not expected to resolve every legal question (that is a solicitor’s role), but is expected to note material defects or risks that would affect the property’s value or condition. Surveyors’ professional statements (e.g. the RICS Home Survey Standard and related guidance) emphasise that any known limitations or risk factors must be flagged to the client. Notably, a court assessing a surveyor’s conduct will consider RICS guidance: conforming to RICS-recommended practice can provide a strong defence in negligence.
In terms of flood and riparian issues, a competent surveyor should:
- Note the proximity and condition of any water features, including streams, ponds or culverts on or near the property. This includes observing bank levels, drainage outlets, soakaways or evidence of damp/standing water.
- Physically inspect any drainage systems or streams visible from the property (while respecting safety). The surveyor may also take soil samples or lift hatches if necessary for a basic check of soakaway or drainage performance.
- Refer to publicly available information (floodplain maps, Environment Agency risk data) where indicated, and recommend that the client obtains a detailed flood risk or environmental report if appropriate.
- Advise on ground conditions (e.g. chalky clays or peat can exacerbate flooding or subsidence), and recommend specialist testing (soakaway test, percolation test) if needed.
Case Law: Hart v Large and Negligence Liability
If a surveyor omits to do so and serious water-related issues emerge later, they may face a negligence claim. One instructive example is Hart v Large (2020), upheld on appeal in Large v Hart [2021] EWCA Civ 24. In that case, a HomeBuyer Report surveyor failed to warn of recurring water ingress and damp in a bungalow. The buyers subsequently discovered extensive defects and sued the surveyor (among others). The court found the surveyor negligent for not drawing attention to the obvious water problems in his report. Damages of nearly £390,000 were awarded to the buyer. The Court of Appeal emphasised that, although this was an unusual case, a surveyor with advisory duty cannot simply disclaim responsibility: the professional must give appropriate advice or warnings based on the facts. In short, “the surveyor could not be expected to see all the damp-proofing defects, but he should have seen enough to raise a suspicion”.
This case underscores the principle that surveyors can be liable for negligent omissions as well as misstatements. A surveyor who notes a nearby river or swampy yard but fails to comment on flood risk (for example, to advise obtaining a flood report) may similarly be culpable. Conversely, if the surveyor has taken reasonable steps (on-site inspection, visible signs) and properly recorded any limitations, that will form a robust defence. RICS guidance specifically advises members to document any features they have not inspected (e.g. not inspected signage for sub-surface drains) and to recommend specialist advice when warranted.
Professionals should also remember that a surveyor’s duty is owed to the instructing client, whereas a solicitor’s duty is to their client (even if the client is different). Surveyors generally do not owe a direct duty to lenders or third parties unless additional retainer is expressly given. Nonetheless, in practice a buyer’s solicitor will read the survey report and rely on it, so poor surveying can impact both.
Professional Guidance for Legal and Surveying Practice
In terms of professional guidance, conveyancers and surveyors have concrete resources:
The Law Society Flood Risk Practice Note (2020) offers detailed advice on how solicitors should handle flood risk in transactions. It urges flood searches, thorough enquiries of sellers and insurers, and documentation of flood risks. The Note also flags that flood risk is often a material fact affecting valuation and insurability.
RICS standards set out surveyors’ responsibilities. The RICS Home Survey Standard (professional statement) and other guidance stress that surveyors should comment on problems of significance to the client’s decisions – flooding being a prime example. In negligence cases, RICS guidance notes (such as Surveying Assets in the Built Environment) may be taken into account by courts. In essence, following RICS-recommended procedures provides at least a partial defence. In practice, a surveyor should follow the Red Book requirements for disclosure of limitations and should not hesitate to recommend a full structural survey or environmental report if water ingress is evident.
Recent developments in the law reflect growing concern over flood risk. Climate change has elevated flood risk as a commercial and legal issue, prompting regulators to tighten rules (for example, by rolling out nationwide Lead Local Flood Authority powers for new developments). Insurers and mortgage lenders also now commonly require detailed flood data and maintenance of defences. Together, these trends mean that both conveyancers and surveyors must be vigilant. Failing to advise properly on riparian duties – whether by overlooking a drain in the title or ignoring signs of flooding on survey – can result in client loss and professional liability.
In summary, riparian ownership in England and Wales carries well-defined duties. Conveyancers should identify and explain these duties (in searches, contracts and advice to clients) when a property adjoins water. Surveyors should incorporate flood checks into their inspections and reports. By staying abreast of the legislation (LDA 1991, EPA 1990, etc.), relying on professional guidance (RICS practice statements, Law Society notes), and learning from case law (such as Hart v Large), legal professionals can manage riparian risk. Clear communication of these issues to clients, for example, by listing riparian maintenance obligations in the contract or raise queries about culverts, is prudent practice.
If you believe your solicitor or surveyor failed to advise properly on riparian ownership, drainage liabilities, or flood risk, you may have a claim in professional negligence. At Carruthers Law, we specialise in complex, high-value negligence cases and act for clients across England and Wales.
We offer clear, strategic advice and act swiftly where professional standards have fallen short.
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