Drainage Survey Preparation Checklist

Walk the whole plot and mark on a sketch every chamber cover, grating, gully and pipe outlet you can find, including ones set into paving and planting.

The features nobody has thought about for a long time are exactly the ones a surveyor will want to see first.

Note where a cover appears to have been paved, decked, turfed or planted over, and write down how you know it is there.

A cover somebody remembers but cannot see is a genuine finding, and it may determine whether a survey can be completed.

Record where each downpipe ends, including whether it enters a gully, a chamber, a pipe at ground level or simply discharges onto the ground.

Downpipe terminations are the easiest part of a system for an owner to record and among the most useful to have in advance.

Note any outlet, pipe end or channel near a boundary, including anything visible on the far side of a fence or wall.

What happens at the edge of a plot often decides how far a survey can usefully go.

Leave every cover and grating in place while preparing, and photograph each one where it sits rather than opening anything.

Lifting covers and entering chambers carries real hazards and belongs entirely with the qualified professionals attending.

Photograph each feature with something ordinary beside it for scale, and label each photograph with its position on your sketch.

Unlabelled drainage photographs become impossible to place within a short time, even for the person who took them.

Write down exactly what you have observed, such as slow draining, gurgling, a smell, water standing at a gully or water appearing where it should not.

Precise wording matters here, because several quite different situations get described by owners in the same loose terms.

Note whether the symptom follows use of a particular fixture or appliance inside the property, and which ones make no difference.

What does not trigger a symptom narrows things down as effectively as what does, and it is rarely mentioned.

Record whether the symptom follows heavy rain, follows use inside the property, or appears with no obvious trigger at all.

This single distinction shapes how a survey is approached and is often the first question asked on arrival.

Note whether the symptom is a one-off, recurring or continuous, and whether it has changed in character since it was first noticed.

A pattern that is worsening reads very differently from one that has been stable for as long as anybody remembers.

List anything already tried, including clearing, rodding, chemical products or work by others, and whether each made any difference.

Do not attempt clearing work in preparation for a survey; leave the system as it is so that a professional sees it unaltered.

Photograph or film the symptom while it is actually happening rather than describing it afterwards from memory.

Most drainage symptoms are intermittent, and a survey carried out on a quiet occasion may find nothing at all.

Decide who will be present throughout, and make sure that person knows the property, the symptoms and where the covers are.

A survey with nobody available to answer questions produces a report full of assumptions.

Check whether every gate, side passage and rear access can be opened fully, and note what would have to be moved for equipment to pass.

Side passages accumulate bins, bikes and stored material, and moving it all at the last moment eats into the visit.

Check what parking exists for a working vehicle near the property and whether any restriction applies to the space outside.

Parking and loading restrictions vary; confirm locally with the local authority rather than assuming what applies.

Ask what the attending team needs available during the visit, such as water, power, or access to a particular fixture inside the property.

Requirements differ between organisations, and asking beforehand avoids a survey stalling over something trivial.

Plan where pets and children will be while chambers are open, and tell everybody in the household what is happening.

An open chamber is a hazard; follow the direction of the attending professionals about where it is safe for anybody to be.

Establish whether any part of the system may run beneath neighbouring ground, and ask early whether their agreement would be needed for access.

Access across other land and shared drainage responsibility are matters for the relevant authority or drainage undertaker to clarify.

Ask whether the survey will look at foul drainage, surface water drainage or both, and record the answer before the visit is arranged.

Owners usually assume both are included, and the two are frequently treated as separate pieces of work.

Ask how far from the property the survey extends and where it stops, including whether it reaches the boundary or goes beyond it.

Where responsibility for the system changes is a question for the relevant authority or drainage undertaker, not for the surveyor alone.

Ask what typically cannot be reached or seen and why, so that a partial result does not come as a surprise afterwards.

Every survey has limits, and knowing them beforehand prevents a limited result being read as a clean one.

Ask what happens if the system turns out to serve more than one property, and how that would change the work.

Whether a run is shared, and what that means for responsibility, is for the relevant authority or drainage undertaker to confirm.

Confirm whether anything would need to be dug or opened, and agree in writing that nothing is excavated without your express agreement.

Excavation is a different matter from surveying, and the two get bundled together in conversation more often than in writing.

Ask who will attend, what equipment they will bring and whether a return visit is often needed for anything that comes up.

Knowing that a second attendance is normal for certain findings stops it feeling like a failure of the first.

Ask for a plan showing the runs that were traced, with the covers and outlets identified on it in a way you can relate to the property.

A plan is the output that keeps its value long after the immediate question has been dealt with.

Ask for written findings in terms you can follow, and say plainly that you would rather have plain language than a list of abbreviations.

A report you cannot read cannot be passed usefully to a designer, a builder or a future owner.

Ask what recorded footage or stills you will receive, in what form, and how they relate to positions on the plan.

Footage without positions attached is nearly impossible to use for anything later on.

Ask that what was observed and what is interpreted from it are set out separately, so you can see which is which.

Interpretation is a professional judgement; treat it as theirs to make and record it as such rather than adopting it as fact.

Ask for the limitations of the survey to be stated in writing, including everything that could not be reached, seen or established.

The limitations section is where the honest picture sits, and it is the part most often skipped by everybody reading it.

Agree how the findings will be provided and keep your own copy independently of anybody else involved in the project.

Reports held only by a contractor or agent have a habit of becoming unavailable exactly when they are needed.

Note the weather in the period beforehand and mention it, since ground and system conditions at the time affect what can be seen.

Owners rarely think to mention the weather, and it can be the reason a visit finds less than anybody hoped.

Mention anywhere you have previously seen water standing in a chamber or a gully, so it is expected rather than discovered.

Do not attempt to drain, bail or clear standing water yourself; leave the system as found for the attending professionals.

Note where a structure, decking, planting or a hard surface sits over something you believe a run passes beneath.

Obstructions above a run frequently define the boundary of what a survey can establish.

Ask whether the property should be in normal use or left unused while the work is taking place, and arrange the household accordingly.

This is easily arranged if asked about beforehand and impossible to sort out once everybody has arrived.

Write down where you already suspect there is more system than can be reached, and raise it as a question rather than an expectation.

Naming a suspicion in advance means it gets addressed in the report instead of quietly omitted.

Ask what sort of finding would call for a further visit and how that is normally handled.

Understanding the usual sequence stops a partial first visit from feeling like something went wrong.

Write down which parts of the system were reached and which were not, in your own words, alongside the report itself.

Your own summary is what you will actually reread, and it keeps the limitations attached to the findings.

Keep your symptom history and photographs filed with the survey, since together they tell a story neither tells alone.

Findings from one occasion make far more sense beside a history recorded across many.

Write down every question the findings raise for you and take them back to the professional rather than settling them yourself.

Interpreting drainage findings and deciding what should follow are matters for qualified professionals.

Decide who else needs a copy, such as a designer or a builder, and record who has been given one and when.

Drainage findings routinely fail to reach the person designing over the top of the system.

Record which of your plans now depend on something the survey found, and which are entirely unaffected by it.

Separating the two stops a whole project stalling over a finding that touches only part of it.

Resist acting on a partial finding, and note explicitly what remains unresolved until somebody qualified has advised.

Any remedial work, connection or alteration arising from a survey belongs with qualified professionals and, where relevant, the responsible authority.