Site Drainage Feature Inventory Record Checklist

Walk the full boundary and every corner of the plot before writing anything down, including the parts nobody goes to and the strip behind any outbuilding.

Features sit where nothing else happens, which is precisely why they are forgotten by everyone who has lived with them.

Put anything on the list that might be drainage, including hollows, channels, gravel strips, pipe ends, covers and low planted areas you cannot explain.

Removing something from the list later is easy; noticing it for the first time long afterwards is not.

Give each entry a number and mark that number on a rough plan of the plot, so a description and a position never become separated from each other.

Lists without positions and plans without descriptions are each roughly half as useful as the two kept together.

Photograph each numbered feature from far enough back to show where it sits, and note what you can see from where you stood.

A close photograph of a lid tells nobody where the lid is, and locating it again is most of the work.

Photograph from ground level only. Lifting covers, entering chambers or clearing material is work for a qualified drainage professional.

Follow each downpipe to where it disappears and record what it appears to enter, without concluding anything about where the water goes afterwards.

Where rainwater enters the ground is one of the most useful entries on the list and one of the least often written down.

Record the places you could not get to, such as behind a locked gate or under dense planting, rather than leaving a silent gap in the list.

A named gap prompts a question later; an unnamed one is simply read as an absence of features.

Walk the plot again at a different time of year, since a channel hidden by long grass and a cover buried under leaves appear in different seasons.

Features reveal themselves as the garden changes around them, so a single walk produces a single season's list.

Keep two columns for every feature: one for what it looks like, and one for what somebody has actually told you it is.

Merging them produces an inventory in which every guess reads exactly like a fact, which is worse than no inventory.

Write down who told you what a feature is and when, whether that was a previous owner, a neighbour, a contractor or a document.

The source is what a professional weighs, and an unattributed name on a list carries no weight at all.

Write unknown where nobody knows, and resist filling the gap with the most likely word, since a plausible name is treated as a known one.

An honest unknown gets investigated; a confident wrong name sends everybody looking in the wrong part of the plot.

Ask whoever designed or built a feature whether it has a designed outflow connection, and record the answer in their words rather than your summary.

Whether water is intended to leave a feature by pipe or into the ground changes how everything you later observe should be read.

What any feature is and how it works is established by a qualified drainage professional from the records and the site, not from what can be seen at the surface.

Ask whether any feature is lined, and note that you asked even where the answer was that nobody knows.

A record of the question having been asked is itself useful, because it stops the same gap being rediscovered by each new adviser.

Write the feature's proper name from the paperwork where one exists, rather than the household shorthand everyone has used for years.

Words like soakaway and drain are used on most plots for several different things, and a professional will not know which you mean.

Look through the papers that came with the property for drainage drawings, searches, guarantees or completion documents, and note which features each one mentions.

Documents that exist and were never read are the commonest source of an answer nobody thought was available.

Write down anything a previous owner, a neighbour or a long-standing contractor has said about a feature, dated and attributed to them.

Recollection is not a record, but an attributed recollection is a lead a professional can follow or set aside deliberately.

Note whether whoever installed each feature can still be contacted, since questions become far harder to answer once that person has gone.

Access to the person who dug it is a resource with an expiry date, and most owners discover this after it has passed.

Mark each feature as documented, described by somebody, or unevidenced, and keep those three categories visibly apart on the list.

The unevidenced column is the working list for everything that follows, and it disappears the moment the three are merged.

Record any landscaping, paving, extension or repair carried out since the feature was installed, and whether anybody checked how it affected the feature.

Later work routinely changes what arrives at a feature without anything that anyone would call drainage being touched.

Keep copies of any drawings alongside the inventory rather than filed separately, and note on the list which drawing covers which numbered feature.

Drawings filed apart from the list are reliably lost at the point the list finally gets used.

List any shallow planted hollow, dished lawn area or low border that water appears to reach, and ask whether it was designed to take water.

A feature doing a drainage job while looking like a border is maintained like a border, which is how it stops working.

Record any long shallow grassed channel running across the plot, including one that reads simply as a dip in the lawn.

A route water is meant to travel along is invisible in dry weather and is routinely levelled by the next person who improves the lawn.

Note paved or gravelled areas that appear to let water through rather than shed it, and ask whether they were built that way deliberately.

A surface built to take water into itself is treated very differently from one built to throw water off.

Record any kerb, upstand or raised edge whose purpose nobody can explain, and photograph it before anybody decides it is untidy.

Edges frequently define where water is allowed to go, and they are removed during landscaping without a second thought.

Note where the lawn is a different colour, texture or firmness in a regular shape, and mark that shape on the plan.

Regular shapes in grass usually follow something buried, which is a lead worth handing over rather than digging into.

Do not open ground to find out what a pattern follows. Buried services and structures are established by qualified professionals before anything is dug.

Mark on the inventory which features you would want anyone cutting, clearing or tidying the garden to be told about.

Most damage to these features is done competently and in good faith by somebody who was never told what they were looking at.

Pull every unexplained feature onto a single short list, with its number, its position and a photograph, and keep that list at the front.

Professionals ask for this list first, and it takes one walk to produce rather than a site visit to compile.

Record any visible pipe end, outfall or opening at a ditch, bank or boundary, and note whether anything was coming out of it when you looked.

A pipe end nobody can account for connects to something, and finding out what is a question rather than an excavation.

Where a pipe discharges beyond your boundary, responsibility is a matter for the relevant authority and the parties involved rather than something to settle yourself.

Note covers that differ from each other in material, size or age, and record those differences rather than treating all covers as one category.

Differences between covers frequently mark different systems installed at different times by different people.

List anything you have been told is disused or abandoned, attribute the statement, and keep it on the inventory rather than removing it.

Features believed abandoned turn out to be live often enough that deleting them from a record is a decision, not a tidy-up.

Record any feature that has recently started behaving differently, including one that now holds water when it previously did not.

Change over time is more informative than any single observation and is the part memory loses first.

Keep the unknowns as questions for a qualified professional rather than resolving them by lifting, rodding, digging or tracing anything yourself.

Nearly every way an owner might satisfy their curiosity here carries a risk that the answer is not worth.

Lifting covers exposes open drainage and gases, and excavation risks buried services. Both are work for qualified professionals with the right equipment.

Ask whether any feature appears to serve more than one property, and note anything a neighbour has said about drainage crossing between your plots.

A shared arrangement carries duties and constraints belonging to more than one household, and neither household usually knows it does.

Whether drainage is shared, and what that means for responsibility, is confirmed with the drainage undertaker and the local authority rather than assumed from appearance.

Bring the plan, the numbered list and the photographs into one document rather than three, so nothing arrives at a conversation on its own.

Split records get partially forwarded, and the half that goes missing is usually the plan.

Label plainly which entries are assumption and which are evidenced, and put that note at the top rather than in the small print.

Anyone reading the list will otherwise treat the whole of it as equally reliable, which is the failure this record exists to avoid.

Ask a qualified drainage professional what is missing from the inventory before the site is discussed in any detail, and record what they say.

One early answer about what to collect saves a wet season spent recording the wrong thing.

Keep the inventory somewhere it stays with the property rather than with you, and tell whoever else lives there where it is.

The record's value is entirely in being found by the next person, and that is a filing decision rather than a drainage one.

Add to the inventory whenever anything is built, paved, planted or dug, noting what was done and who did it.

The gap between what was recorded and what exists opens one small job at a time and is never closed retrospectively.

Keep observations about how water behaves in a separate record from this inventory, and cross-reference them by feature number.

What a feature is and what it appears to be doing answer different questions, and merging them makes both harder to read.