Module 2 — Who Owns What — Catalyst Training Academy

The single most important rule

⚠️ Always determine ownership BEFORE investigation or repair

Water companies treat unauthorised work on their systems as trespass. They will not normally reimburse third-party costs even where the fault is theirs. Working blind on a public lateral drain or sewer can leave Catalyst (or its supply chain) bearing the entire cost. The 14-question decision tree exists to stop this happening.

Key dates that decide ownership

Date	What happened	Why it matters
1 October 1937	Cut-off for Section 20 / Section 24 vesting under the Public Health Act 1875/1936 (E&W) and Sewerage (Scotland) Act 1968.	Pre-existing sewers serving more than one curtilage on this date are public, even if curtilages later merged or buildings were demolished. "Once a sewer, always a sewer."
1 October 1937 (Scotland)	Same date — Section 24 transfer.	As above for Scotland under the 1968 Act.
1 July 2011	Private Sewers Transfer Regulations took effect in England & Wales.	Most private sewers + lateral drains in use at that time, and connected to the public sewer system, transferred to the water companies.
2016	Private pumping stations transfer (England).	Private pumping stations connected to the public sewer system transferred. Single private pumping stations serving one curtilage remain private.
1 April 2017	All English business customers in the retail water market.	Relevant when distinguishing the retailer from the actual sewer operator.

The Decision Tree — interactive

Step through the questions to find the answer for any drainage system. The full WRc tree has 14 questions; this practical version captures the decisive ones.

🧷 Special cases (not in the simplified tree)

Cesspool: never an outfall. Pipes feeding it = private drains. Banned in Scotland.
Single private pumping station serving one curtilage = remains private (not transferred 2011 / 2016).
Crown / Duchy of Cornwall / operational railway / dock land = exceptions. Go straight to the sewer record map.
Northern Ireland / Channel Islands / Isle of Man = out of scope of the DRB. Contact local Sewerage Authority.
Sewer maps are NOT conclusive. Many public sewers are missing. Absence from the map does not prove the asset is private.

Match the asset to the responsible party

Drag each item from the left column onto the correct slot on the right.

Drag from here →

A foul drain inside the curtilage of a 1990s house in England

The lateral drain crossing the boundary into the highway, in use since 2005, on a Thames Water-served property

A pre-1937 shared private sewer in Manchester serving two cottages, both still occupied

A single private pumping station serving one isolated farm in Yorkshire (built 2018)

A cesspool in a Welsh single-dwelling property

A lateral drain in a property built and connected to the public sewer in 2014 (England)

Drop on the right slot

Owner / property responsibilityInside the curtilage, owner pays for repair

Public — water companyLateral drain in use & connected by 1 July 2011, English WaSC area → transferred

Public — water companyPre-1 Oct 1937 + served >1 curtilage → Section 20 sewer, vested under PHA 1875/1936

Owner / property responsibilitySingle private pumping station serving one curtilage = remains private

Owner / property responsibilityCesspool with no outlet — never a sewer, always private

Possibly developer / possibly publicBuilt post-2011 → not automatically transferred. Section 104 agreement may apply; transfer may be pending

The "Once a sewer, always a sewer" rule

Three court cases established this principle and it still binds today:

St Leonard Shoreditch Vestry v Phelan (1896) — first established the rule
Kershaw v Smith (1913) — affirmed
Beckitham Properties Ltd v Minister of Housing (1967) — affirmed

So if a sewer was vested before 1 October 1937 because it served more than one curtilage at that time, it remains a sewer even if:

The two curtilages have since become one (e.g. cottages joined into a single house)
One of the buildings has since been demolished
The drain has been disconnected (unless reconstructed to achieve this)

Cost apportionment for shared private systems

If a drain or sewer is found to be private and shared, the costs need to be split between the users. WRc gives three principles in the absence of a deed-based legal agreement:

Costs shared by all users of each part of the system
Costs proportional to each user's contribution to flow in that part
No user contributes to costs of a part of the system they don't use

For foul flows, assume equal flows per house — unless building types differ significantly (e.g. office, school, block of flats). Then use BS EN 12056-2 discharge unit method (UK = system type 3). For surface water, apportion by surface area drained per BS EN 12056-3.

Worked example

Four houses (A, B, C, D) on a private street built in 1965 share a single private sewer running along the front gardens, before connecting to the public combined sewer in the highway. A break occurs in the section between House B and House C.

✓ Apportionment

Houses A and B do not use the section between B and C. Houses C and D do use it. So the cost of repair is split between C and D — equal halves, since both are houses with comparable foul flow. Houses A and B do not contribute. Note: built 1965 → post-1937 → was a private sewer when built. Was it transferred 1 July 2011? Yes — it was in use, served more than one curtilage, and connected to the public sewer system. It is now a public sewer. Repair is the water company's responsibility.

Lesson: post-1937 doesn't keep something private — the 2011 transfer caught most older shared private sewers.

Information you need from the customer

Property build date (deeds, old maps, voting registers, directories)
Curtilage layout — fence lines, shared driveways, neighbours sharing the system
Connection arrangements — direct to public sewer, via shared drain, septic tank, cesspool
Any deed-based easements or shared maintenance agreements
Whether wastewater charges appear on the water bill (evidence of public connection)

Knowledge check — Module 2

Q1. A semi-detached house in Birmingham was built in 1925. The property's foul drainage runs through a shared sewer with the neighbouring house, then to the public combined sewer in the road. A break has occurred in the shared section. Whose responsibility?

Q2. A 2018-built detached house in Yorkshire has a single private pumping station and rising main inside the curtilage. The pumping station fails. Whose responsibility?

Q3. The customer believes their drain is on the public sewer map. The map shows nothing. What can you conclude?

Q4. A property in Welsh Water's area was built in 2018. There is no Section 104 agreement on file. The lateral drain has failed. Most likely:

Q5. A block of flats in London has a foul drain serving all 8 flats. WRc considers each block to be:

Q6. The 1 July 2011 Private Sewers Transfer in England & Wales transferred:

Q7. Which Act vested pre-1 October 1937 sewers serving more than one curtilage in the local authority (and hence into the modern water companies)?

Q8. Two terraced houses share a private foul sewer along the rear gardens, breaking into the public sewer in the road. The break is in the section serving only House A (i.e. before the join with House B's pipe). House B's owner says they shouldn't pay anything. WRc's principles say:

Q9. A drain in a customer's deeds has been "in use" for 25 years but no formal easement is recorded. The customer asks if they can rely on the right to access for repairs. WRc says:

Q10. A handler is told to investigate a blockage in a public sewer in the highway. They proceed without contacting the water company. The risk is:

Q11. The DRB covers ownership in:

Q12. A foul drainage charge appearing on a customer's water bill is good evidence that:

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