Checklists · Drainage
Garden Flooding Observation Record Checklist
Help an owner record a flooding event accurately while it is happening and in the period afterwards, so that a qualified drainage professional and, where needed, the relevant authority are handed dated evidence rather than recollection.
8 sections · 48 planning prompts · educational owner-side preparation
https://www.builddesignhub.com/checklists/drainage-and-site-discussion/garden-flooding-observation-record · Build Design Hub — educational planning resource. Requirements vary by project and location.
Scope
What this checklist covers
The preparation ground these prompts walk through.
- Capturing an event safely while water is still present
- Marking how far the water reached and what it covered
- Where the water appeared to arrive and where it eventually left
- What is left behind once the water has drained away
- What changed on or near the plot before the flooding began
- Whether the event repeats and what pattern it follows
Audience
Who this checklist is for
- Owners whose garden has flooded and who want a proper record of it
- People who have had water reach a building, an outbuilding or a store
- Owners noticing flooding beginning where it never used to happen
- Anyone who has been asked to describe what happened during the event
Timing
When to use it
- Recording a flooding event as it happens and immediately afterwards
- Marking the extent water reached in a way that can be checked later
- Noting what changed on or near the plot before the flooding began
- Building a dated record of repeat events across different spells of weather
- Preparing evidence for a professional and for the relevant authority
Limits
When it is not sufficient
This is general planning preparation. These situations need a qualified professional, and often the relevant authority.
- Establishing the cause of flooding or deciding what should be done about it
- Deciding which land, road or watercourse the arriving water is coming from
- Any pumping, clearing, protective work or response during an event
- Replacing professional advice, a drainage survey or a formal report
- Insurance, liability or any other matter belonging with your own advisers
The checklist
Work through the sections
Tick the boxes on paper or on screen — nothing is stored, so print the page if you want to keep your marks.
1.Capturing the event safely while water is still there
The most valuable record is made while water is present, and it is also the moment when the risk is highest. Everything here assumes you stay on solid ground.
Keep out of moving or deep water, away from open covers and away from anything electrical, and record only what is visible from safe ground.
Floodwater hides the ground beneath it, so a familiar garden becomes genuinely unpredictable while it is under water.
Floodwater may be deep, fast or contaminated; where anything is uncertain stay clear and leave it to the emergency services or a professional.
Photograph from safe positions and let the images carry their own time and date rather than relying on memory afterwards.
An image with its own timing attached is evidence, while a description written up later is only ever recollection.
Use the same viewpoints each time, so images from one event can be laid directly alongside those from another.
Comparability is what turns a set of dramatic pictures into a record of how a site is actually behaving.
Include something permanent in every photograph, such as a wall, a step, a post or a doorway, so the extent can be read from the image later.
Water photographed against nothing recognisable cannot be interpreted by anybody who was not standing there.
Take a short video showing where water is moving and in which direction, since direction is exactly what still images lose.
Direction of flow separates water arriving from water failing to leave, which is the first thing a professional wants to know.
Write down what the weather had been doing beforehand and what it was doing at the time, in plain descriptive terms.
Whether an event followed prolonged rain or a sudden downpour points at quite different explanations.
2.Marking how far the water actually reached
Extent is the part of the record that fades fastest and matters most. Marking it while it is still visible takes moments and cannot be recovered afterwards.
Mark the edge the water reached with something harmless such as a cane or a peg, while the line is still clearly visible.
A physical mark can be photographed, measured by somebody qualified and checked against the next event.
Photograph the water against a doorway, step or wall so its height can be judged later against something that is not going to move.
Height read against a permanent feature is checkable, whereas an owner estimate of depth rarely survives questioning.
Write down what was under water, including beds, paths, a lawn, a shed base, a store and the ground against the house.
The list of what was covered is what makes the extent meaningful to somebody who does not know the garden.
Record with particular care any point where water reached a building, an air brick, a threshold or a below ground area.
This is the observation that changes the urgency of everything else in the record.
Water reaching a building must be raised promptly with a qualified professional, and more urgently still where a below ground room is involved.
Once the water has receded, photograph the line of silt or debris it left behind, since that records the extent better than memory does.
The deposit line is usually sharper and more extensive than what anybody remembers seeing while the water was there.
Draw the extent onto a plan of the plot rather than describing it in words alone, and put the date on the drawing.
A dated outline on a plan can be overlaid with the next one, which words alone never allow.
3.Where the water came in and where it left
Arrival and departure are separate questions with separate answers, and confusing the two sends everybody looking in the wrong place.
If it is safe to look while water is still arriving, note where it appears to be coming from and mark that point on the plan.
The arrival point is visible for a short while only and is almost impossible to establish afterwards.
Do not approach a watercourse, ditch, open cover or fast moving water to establish where flow is coming from.
Record whether water appears to arrive over or under a boundary, from a track, a field, a road or a neighbouring plot.
Where water crosses a boundary the situation involves other people, and an accurate dated note is worth a great deal.
Water arriving from beyond the boundary raises responsibility questions for the relevant authority and the parties involved.
Note whether water appeared to rise out of the ground rather than flow across it, and record what you saw without concluding why.
Rising water and flowing water look quite different at the time and point at entirely different investigations.
Record any place where water appeared to come back up out of a gully, channel or cover, and report it rather than interpreting it.
This observation is specific, serious and easy to describe, and it is the sort of thing owners frequently mention to nobody.
Water coming back up out of a gully or chamber should be reported promptly to the drainage undertaker or a qualified drainage professional.
Note where the water eventually went and which part of the plot cleared first and which cleared last.
The order in which areas clear says more about the ground than the peak extent does.
Record anything the water appeared to be held back by, such as a wall, a raised edge, a fence base or a build up of debris.
Obstructions turn a passing flow into standing water, and they are often something recently added.
4.What the water leaves behind once it goes
The aftermath is easier to record than the event itself and is routinely cleared away before anybody photographs it.
Photograph the silt, grit and debris left behind, noting where it came to rest and how thick it appears in ordinary terms.
Deposits map both the extent and the direction of flow, which no later description recovers.
Record anything the water brought with it, including material that has clearly come from beyond your own boundary.
Material with an obvious origin is among the more persuasive things in an owner record.
Write down any smell, oily film, discolouration or foam you notice, and pass it on without sampling, clearing or explaining it.
Anything of this kind widens who has to be involved, so it belongs in the record at once and in plain description.
Anything suggesting contaminated water is for the relevant authority and a suitably qualified specialist, and should not be handled.
Record which plants died back, which recovered and where grass yellowed, photographing those areas again as the growing season goes on.
Plant damage is a slow record that keeps showing the extent long after every other trace has gone.
Note how the ground recovered by returning to it and dating each visit, rather than estimating a period you did not actually measure.
Dating each return builds the recovery picture out of observations rather than out of a remembered sense of how slowly things dried.
List anything spoiled or discarded with photographs, and ask your insurer separately what they need to have recorded.
Photographing before anything is thrown out takes moments and cannot be done retrospectively.
Insurance requirements are a matter for your insurer alone; this record is not insurance advice and must not be treated as such.
5.What changed before the flooding started
Where a garden has begun flooding when it never used to, the answer is often something that changed nearby rather than something that changed in the sky.
Write down whether this has happened before and what you remember about earlier occasions, marked clearly as recollection.
Whether an event is the first or the latest of several changes what everybody is looking for.
List changes on your own plot, including new paving, a shed base, a raised bed, a fence or altered ground levels.
Owners tend to look outward first, and the honest record starts with what changed inside the boundary.
Note any building, paving or ground work on neighbouring land or close by, and roughly when you first noticed it.
Work next door is frequently noticed at the time and then never connected with anything that follows.
Record works on a road, a verge, a field, a ditch or a watercourse near the property, without concluding that they caused anything.
The observation is yours to make; the connection between it and the flooding is not.
Attributing a cause is for a qualified professional and, where public infrastructure is involved, for the relevant authority.
Note anything near the property that used to be cleared, cut or maintained and now appears to have stopped being done.
A ditch that was once cleared regularly and now is not is exactly the kind of change nobody records.
Record any ditch, channel, gully or grating that looks obstructed, and report it to whoever is responsible rather than clearing it yourself.
Reporting creates a record; clearing it yourself removes the evidence and may not be yours to do.
Clearing a ditch, gully or watercourse may not be your responsibility; ask the relevant authority or drainage undertaker who holds it.
6.Whether it repeats and what pattern it follows
One event is an anecdote. Several events recorded consistently start to show a pattern, and the pattern is what anybody investigating will want.
Keep one dated entry per event rather than merging them into a general account, so a pattern can be read across the record.
Merged accounts lose the differences between events, and the differences are the informative part.
Note whether each event followed heavy rain, prolonged rain or no obvious rain at all, described in plain terms.
An event without heavy rain beforehand is a very different finding from one that followed a downpour.
Record whether the water covered the same ground each time or reached further, and mark both extents on the same plan.
Extents drawn over one another show at a glance whether the situation is stable or worsening.
Note the season each event occurred in, since a pattern across the seasons is one of the more useful things an owner can supply.
Seasonal patterns point at quite different explanations from events scattered evenly through the calendar.
Note anything happening nearby at the same time, such as a full ditch, a high watercourse or water lying along the road.
Context beyond the boundary often distinguishes a local problem from a much wider one.
Record the occasions when water nearly reached somewhere but did not, since near misses show how little margin remains.
Near misses never get written down because nothing was damaged, and they are exactly what shows a trend.
7.What neighbours and the wider area saw
Other people were watching the same event from different places. Their accounts are valuable provided they are kept as accounts rather than absorbed as fact.
Ask neighbours what they saw and when, and write it down as their account rather than adopting it as established fact.
Somebody with a different view of the same event often saw the arrival that you missed entirely.
Note how far the flooding extended beyond your own property, including the road, a footway, a track or nearby land.
Whether an event stopped at your boundary or covered the whole area determines who needs to be involved.
Ask longer standing residents whether this has happened before at this property and what they remember about it.
Local memory frequently reaches back further than any document you are likely to obtain.
Find out whether anybody reported the event to the relevant authority, and record what came of that report.
An existing report may already have generated information that saves you repeating the exercise.
Avoid adopting a shared local explanation as fact, and keep it in your notes as an account still to be checked.
A confident local theory can send an investigation in one direction and keep it there for a long time.
Keep your record factual and free of blame, since it may need to be shared with a neighbour or an authority later.
A neutral record can be shown to anybody, while an accusatory one narrows who will engage with it.
8.Putting the record where it can actually be used
A flooding record that lives in a drawer in the building that flooded is not a record. The last step is making it usable by somebody else.
Assemble each event into one file with its date, photographs, plan and notes kept together rather than scattered across devices.
Anything not assembled at the time is effectively lost by the time it is needed.
Keep a copy somewhere other than the property, since a record that floods along with the garden is no record at all.
This is obvious in hindsight and almost never done in advance.
Set the observations out first and your own explanation second, under a heading that plainly marks it as your view rather than a finding.
Mixing the two makes the whole record easier to dismiss, including the observations that are solid.
Add a short page of what stayed hidden during the event, including where water disappeared to underground and what you never got a clear view of.
Naming the hidden parts of an event stops everybody treating the visible parts as though they were the whole story.
Ask who this should be reported to locally, report it there, and keep a note of any reference you are given.
Reports feed records that are held well beyond your property and can matter considerably later.
Who a flooding event is reported to varies locally; ask the relevant authority and the drainage undertaker rather than assuming.
Ask a qualified drainage professional what else should be captured during the next event, and prepare for it in advance.
Knowing in advance what is wanted is the difference between a useful record and another set of dramatic photographs.
Preparation
Documents and information to gather
Having these to hand usually makes the first conversation shorter and more useful.
- Dated photographs and video from each event, taken from safe fixed positions
- A plan of the plot with the extent of each event drawn and dated on it
- Notes of the weather before and during each event, in plain description
- Records of changes on the plot, next door and in the wider area, with dates
- Accounts from neighbours, clearly marked as their own recollection
- Any reference given when an event was reported to the relevant authority
Records
Decisions to record before work begins
Write these down in your own words, with the date, so everyone is working from the same version.
- What you will photograph and mark the next time water arrives on the plot
- Which areas you now treat as at risk of flooding and which you do not
- Who you have reported the event to and what you were told in reply
- What stays out of the affected ground until somebody qualified has looked
- Which of your notes are observation and which are your own interpretation
Professional review
Questions to discuss with qualified professionals
Bring these to the relevant qualified professional, supplier or authority. Requirements vary by project and location.
- What do the extents I have recorded across these events suggest to you?
- Which of my observations point at water arriving and which at water not leaving?
- What should I capture during the next event that I did not manage this time?
- Who should this be reported to, and what does reporting it actually achieve?
- What can be established about the existing drainage before anything is opened up?
- What should be kept out of the affected ground until it has been looked at?
- How do the works I have noted nearby affect what needs investigating here?
- Which parts of this need to go to the drainage undertaker rather than to you?
Blind spots
Commonly overlooked items
- Photographs with nothing permanent in the frame to read the extent against
- The tide line against a wall or a door, washed off or painted over well before it was needed
- Near misses, which never get recorded because nothing was actually damaged
- Works on a nearby verge, ditch or field, noticed at the time and never written down
- A gully seen coming back up during the event and then reported to nobody
- The only copy of the record kept inside the building that floods
- Neighbour accounts absorbed into the story until nobody knows what was observed
What this checklist does not do
- Floodwater can be deep, fast moving and contaminated; observe from safe ground and never enter it to make a record.
- Nothing recorded here establishes the cause of flooding or who is responsible for it.
- Water coming back up out of a gully, or reaching a building, needs prompt professional and authority attention rather than observation alone.
- This is not insurance, liability or legal advice; those questions belong with your insurer and with suitably qualified advisers.
More preparation
Related checklists
Inspiration
Related Ideas Library pages
Design directions to explore once the preparation is done.
Go deeper
Related Build Design Hub guides
Explanatory planning guidance behind the decisions on this page.
Drainage & Site Discussion Checklists
Observation and record-keeping checklists for water on site — what to watch, what to photograph, and the questions that belong with a drainage professional.
Browse all Drainage & Site checklists →