Land Drainage and Soakaway Coordination Questions Checklist

List every proposal on the plot that involves water in the ground, including ones from different trades, different quotations and different times of year.

Owners rarely hold the two side by side, because they arrived weeks apart in response to different problems.

Write next to each proposal whether it is taking water out of the ground or putting collected water into it, in plain words.

That single distinction is what separates two arrangements that can look almost identical once buried.

Record who proposed each arrangement, what problem they were asked to solve, and what they were shown of the rest of the plot.

Each party answered the brief in front of them, and the brief in front of them is usually half the site.

Note when each proposal was made, since arrangements suggested months apart are rarely thought of as belonging to the same site.

Time between proposals is the commonest reason nobody has considered them together.

Add to the list anything already in the ground that does either job, including work by a previous owner that nobody has mentioned.

A new proposal is often the third arrangement on a plot rather than the second.

Keep a copy of each party's drawing or sketch yourself, even a rough one, rather than leaving each with the party who made it.

You are the only person likely to hold both, and holding both is the entire contribution an owner can make here.

Ask each party directly whether they have seen the other's proposal, and record the answer rather than assuming somebody passed it on.

The answer is very often no, and asking costs nothing compared with finding out afterwards.

Record what information each party was given about the site, including any survey, plan, test result or previous drainage record.

Two proposals based on different information are not really disagreeing; they are answering different questions.

Note how much of the plot each party actually walked, and whether either of them saw the area the other is proposing to work in.

A proposal made from the part of the garden with the problem does not necessarily consider the part with the solution.

Ask whether any ground testing has been carried out, by whom, at what position, and ask for a copy of whatever was produced.

Test results attach to a position rather than to a plot, which is a distinction easily lost in conversation.

What ground testing shows and where it applies is interpreted by qualified professionals; a result from one position is not a statement about the whole site.

Check whether both parties have been given the same drainage records, and send anything you hold to whichever has not seen it.

This is the one part of the coordination problem an owner can simply fix, in an afternoon, at no cost.

Write down any point on which the two parties describe the ground differently, quoting each of them rather than summarising into one account.

The disagreement itself is the useful finding, and it disappears the moment it is tidied into a single version.

Ask each party who they understand is coordinating the water arrangements across the whole plot, and write down each answer separately.

Where the answers differ or are all vague, you have established the position without needing anybody to admit anything.

Establish whether anybody has been appointed to look at the site as a whole, or whether that has simply not been arranged.

Coordination is a role somebody either holds or does not, and it is rarely discussed until something is already buried.

Ask a qualified drainage professional whether positions, depths and outfalls for both arrangements should be settled together, and record what they say.

This is a question with a professional answer, and it is much cheaper asked before the work than traced afterwards.

Whether two water arrangements can coexist on a particular plot is a determination for a drainage designer working with geotechnical advice.

Note who you would approach if something went wrong after both were built, and whether that person has seen either proposal now.

Answering this in advance often makes the case for involving somebody earlier more clearly than any argument would.

Ask in what order the two pieces of work are expected to happen, and whether either forecloses anything about the other.

Sequence decides which arrangement gets the position it wanted, and it is usually set by who is available first.

Write down what you decided to do about coordination and why, dated, whether that was appointing somebody or accepting the position.

A recorded decision is defensible later in a way that a vague recollection of having thought about it is not.

Note what you would do if either party declines to consider the other's proposal, including whether you would appoint somebody to look at both.

A refusal is itself information, and deciding your response in advance stops the diary settling the question instead of you.

Ask each party what their arrangement relies on the ground doing, and write the answer in their words rather than translating it.

A translated answer loses exactly the detail a professional reading it later needs.

Ask each party where the water their arrangement handles finally ends up, and keep asking until the answer is a place rather than a direction.

Away and into the ground are not destinations, and the difference matters when another arrangement is working in the same ground.

Mark both proposed positions on one plan of the plot, at roughly the right places, so their relationship to each other is visible.

Two positions described in words feel unrelated; the same two marked on one sheet often do not.

Note what sits near either position, including buildings, boundaries, retaining structures, trees, neighbouring land and anything you already believe to be buried there.

Both arrangements have to sit clear of things that react to ground being wetted or dried, and that list is site-specific.

How far an arrangement must sit from a structure, boundary or tree is determined by qualified professionals for the particular site and ground.

Ask where any outfall is and what level it sits at relative to what it is draining, without attempting to work that out yourself.

An outfall level is what makes one of these arrangements possible or impossible, and only one party usually knows it.

Ask each party what effect their arrangement could have on the ground beyond the area they are working in, and record the answer.

Both changing and adding water reach further than people expect, and the answers to this question are the ones worth putting side by side.

Altering ground water conditions can affect neighbouring land and structures. That is a matter for geotechnical and drainage professionals, not for a site decision.

Put the question to both parties in writing rather than in conversation, sending each the same short note and keeping a copy.

A written question produces a written answer, and it is the answers rather than the question that you will need later.

Send each party the other's proposal with your note, so neither is being asked to comment on something they have not seen.

Asking somebody to consider an arrangement you have described to them is not the same as showing it to them.

Ask whether either party sees a conflict between the two, and ask for the answer even where the answer is no.

A recorded no is worth having, because it dates the moment at which somebody looked at both.

Decide whether either piece of work starts before you have both answers, and say so to both parties rather than letting the diary decide.

Whichever party is available first otherwise settles the question, which is the least considered way it can be settled.

Ask each party what about their arrangement could still be moved and what could not, and note which of those are physical limits.

Knowing what is genuinely fixed narrows the conversation quickly and keeps it away from preferences.

Keep the whole exchange with the property records rather than in a mailbox, since it explains why the site is arranged as it is.

The reasoning behind a buried arrangement is lost faster than the arrangement itself.

Ask each party what has to be confirmed locally before their arrangement is dug, and whether they have done it or expect you to.

Each party assumes that side of the enquiry belongs to somebody else, which is how a site gets dug without it.

What notification, consent or agreement applies to either arrangement is confirmed with the local authority and the drainage undertaker, and varies by location.

Write down what was laid, when, by whom, and what changed on the plot afterwards, dating each entry as closely as you can.

The history is what an owner can contribute that nobody else holds, and it is more useful than any single observation.

Record where the symptoms actually appear rather than only where you think the cause is, and keep those two things separate.

With buried arrangements the symptom regularly turns up somewhere other than the arrangement, which is why the record matters more than the guess.

Note anything that changed around the time the behaviour changed, including paving, a new roof area, a rerouted downpipe or a neighbour's work.

Coincidence in time is a lead, and it is the part nobody writes down because it seemed unrelated at the time.

Establish whether either installer is still contactable, and note what each says about what they laid, attributed to them.

Two accounts that disagree are more useful to a professional than one account presented as settled.

Ask a qualified drainage professional to look at both arrangements together rather than commissioning separate opinions on each and trying to reconcile them yourself.

Two separate opinions reproduce exactly the division that caused the problem in the first place.

What two existing arrangements are doing to each other is a determination for a drainage designer working with geotechnical advice and whatever layout record survives.

Resist resolving the question by digging, rodding or opening anything, and keep the unknowns as questions for somebody qualified.

Excavation near buried services and structures is exactly the investigation that should be arranged rather than attempted.

Excavation risks buried services and can affect nearby structures. Where and how ground is opened is arranged by qualified professionals.