Before You Dig: A Homeowner's Evidence Protocol for a Waterlogged Garden in Vaud

A wet lawn is not proof that a French drain is needed. Water may arrive from a downpipe, paved slope, blocked channel, compacted soil, groundwater, a leak, or runoff crossing a boundary. Those causes require different remedies and different destinations. The first decision is not which drain to buy; it is what water is arriving, where it can lawfully and safely go, and what observation would distinguish the competing explanations.

For local orientation, read the Vaud guide to garden drainage and contractor decisions. Then treat it as background, not a parcel diagnosis. This article adds a reusable event card and uncertainty ledger for a better first conversation with a qualified professional. Neither tool replaces a drainage design, geotechnical opinion or authority decision.

The decision in one minute

Do not authorize a trench only because a contractor recognizes a familiar pattern. First locate the wet boundary and record when it appears. Water below a roof outlet immediately after rain differs from water emerging through a lawn after several dry days. A muddy band at the toe of a slope differs from water entering a basement at a wall joint. A drain may collect water yet fail as a solution if its outlet is unknown, too high, blocked, unapproved or directed toward another property.

Use three gates. First, determine whether the symptom is rain-linked, persistent, localized or moving from a visible source. Second, establish the proposed receiving point and who can confirm that it is suitable. Third, require a design that explains why the intervention fits the evidence, what can go wrong and how it will be maintained. If a decision-changing fact remains unknown, pause irreversible excavation and authorize only the next proportionate investigation.

Why a drain name is not a diagnosis

“French drain” describes a broad family of gravel trenches, sometimes with perforated pipe, used to intercept or convey water. The label does not state whether the purpose is surface runoff collection, shallow seepage interception, foundation protection, groundwater control or roof-water routing. Each function can require a different depth, filter, pipe fall, cleanout and outlet. A familiar detail can be technically neat and still solve the wrong problem.

The unglamorous question is where collected water ends. If the outlet is not lower than the collection point, gravity will not carry the flow. If it ends at another low spot, it may create a second wet area. If it connects to a sewer or watercourse, rules and approvals may apply. If it infiltrates, local soil capability and receiving-environment constraints matter. A product photograph cannot establish any of those conditions.

The State of Vaud says the admissibility of infiltrating unpolluted water depends on water type and receiving-environment vulnerability. It also points to in-situ testing of local permeability and flags landslide or collapse areas and polluted sites as relevant constraints. See the cantonal infiltration guidance. “It will soak away” should therefore be supported by site evidence and, where required, confirmation from the responsible authority.

Start with water, not with a product

Sketch the house, garage, paved surfaces, roof downpipes, retaining structures, visible drains, slope direction, parcel edge and nearest plausible outlet. Mark the wet and dry boundary. You do not need survey precision for a first observation, but distinguish what you saw from what you inferred: solid arrows for visible flow, dashed arrows for suspected underground routes, and a question mark where the destination is unknown. The sketch gives the homeowner and contractor one shared picture instead of a vague label such as “bad drainage.”

Record when the area becomes wet: during rainfall, shortly afterward, after snowmelt, after irrigation, or without a recent input. Note where water first appears, whether it travels from an upper edge, collects at a low point, comes from a wall, or remains broadly damp. Record whether the symptom is seasonal and whether it changed after paving, construction, grading or a neighbor’s work. These are observations, not conclusions. A single storm can mislead because rainfall intensity, frozen ground, earlier moisture and blocked grates all affect what is visible.

Photograph the same points from the same direction when possible. Keep one wide photograph for context and a closer view of the water boundary, sediment or staining. Record date, approximate time, recent weather, irrigation and any maintenance action such as clearing a grate. Do not remove a cover, enter a chamber or dig near buried utilities unless it is safe and you are authorized. The initial record should reduce uncertainty without creating a new hazard.

The eight-field wet-area event card

The original asset here is a reusable documentation protocol, not a measured claim about Swiss drainage performance. The eight fields below are deliberately chosen to keep observations, assumptions and next decisions apart. Reuse one row for every distinct wet event and attach the sketch or photos. “Unknown” is an acceptable entry: it reveals which quote assumption remains unresolved. The card is not a statistical sample, soil test or engineering report; it prevents unrelated symptoms from being merged into one assumed cause.

Field	Record	Why it changes the decision
Event	Date, duration, rain or irrigation context	Separates weather-linked symptoms from persistent water
Footprint	Wet boundary on the parcel sketch	Distinguishes a point, strip, slope or broad area
Entry and direction	First visible water and flow direction	Helps separate runoff, seepage, ponding and possible leakage
Nearby inputs	Roof outlets, paving, irrigation, spring, upper slope, drains	Identifies sources to inspect before designing collection
Building effect	Distance to wall, doorway, retaining structure or service	Changes urgency and may require another specialist
Existing route	Grates, channels, lids, cleanouts and known outlet	Reveals maintenance issues and unknown destinations
Recent change	Construction, grading, cleaning or diversion	May explain when the pattern changed
Open question	Fact that would most alter the next action	Makes the next visit a test, not just another opinion

A good card can contain several unknowns. If a proposed design relies on an unidentified pipe, untested soil, a boundary assumption or a supposed outlet, the offer should say how that uncertainty will be resolved and who pays if the assumption fails. “Connect to existing drain” should not become authority to connect before locating the pipe, identifying its purpose and checking whether it can receive that water.

A repeatable observation sequence

Use the same sequence each time. First, take a context photograph before changing anything. Second, trace visible surface water from its apparent source toward the wet area, stopping where it disappears or becomes uncertain. Third, note whether it appears clear, carries sediment, has an odor, or emerges from a pipe. These clues do not identify water in a laboratory, but they can show that an assumed clean-water route deserves checking. Fourth, note whether water is moving or standing and whether the wet footprint continues to grow after rain stops.

Fifth, inspect accessible grates and outlets from the surface only. Record debris and whether water is already pooled at the outlet. Do not push tools into unknown pipes or use chemicals. Sixth, compare with a naturally occurring dry interval or another storm if one happens. Do not create a large test by hosing water toward a foundation or neighboring parcel. A controlled watering test should be planned only when the source is understood, there is no risk to structures or others, and the person conducting it can stop immediately. Often a professional should define the test.

Seventh, update the sketch in a different color but preserve the first record. Eighth, phrase the remaining uncertainty as a question: “Does water enter from the upper paved drive, or rise through the lawn?” is more useful than “Which drain should I buy?” The next investigation should separate plausible causes at the lowest safe cost. Depending on the site, that might mean reviewing drainage plans, inspecting a known pipe, conducting an in-situ infiltration test through a qualified person, or obtaining geotechnical advice. It does not automatically mean excavation.

Distinguish the main water pathways

Surface runoff travels over a surface when rainfall or another input exceeds absorption or conveyance. It may arrive from a roof, driveway, terrace, compacted path or higher parcel. Look for flow marks, debris lines, erosion, a wet band beginning at an edge, or a response that starts during rain. The first action may be to inspect a downpipe, restore a blocked grate, review a surface channel or revisit grading. Even a small grade change can redirect water, so consider the building and neighboring land before acting.

Ponding occurs where water collects faster than it leaves. A low spot is not necessarily a soil problem. It may reflect topography, a blocked outlet, a local depression, paving that funnels runoff into a basin, or a receiving point with insufficient capacity. Record the footprint and how it changes after input stops rather than writing only “poor drainage.” If the same spot ponds after every storm, inspect both contributing area and outlet. Filling the low point without addressing inflow can move the puddle a few metres and leave the cause untouched.

Shallow seepage may emerge where a permeable layer meets a less permeable one, along a slope, near a retaining wall or at a foundation. It may present as a line or wet band even when surface runoff is not obvious. A perforated drain might collect it if designed for that function, but depth, filter, outlet and structural context matter. Excavating beside foundations or retaining structures is not merely a landscaping task; it may affect stability or waterproofing and warrants competent assessment.

Groundwater, springs and leaks are separate possibilities. A high water table can saturate a broad area after visible runoff has passed. A spring may continue in dry weather. A leaking water or irrigation line can mimic drainage failure. If water persists without a rainfall relationship, emerges repeatedly from one point, or appears near services, do not assume a stormwater solution. A plumber, utility provider or site specialist may be the better first contact. A drainage contractor should state when the issue falls outside their scope.

The outlet is part of the design

A proposal is incomplete until it identifies the receiving point. Ask the contractor to show the route from collection to outlet, say whether flow is by gravity or pump, and identify access points needed for inspection. If gravity is claimed, the relevant levels should make the route plausible. A pump adds power, controls, discharge routing and a failure mode. Infiltration adds soil and siting questions. A connection to an existing line adds a need to verify that the line exists, can receive the water and may lawfully be used for that purpose.

In Vaud, infiltration and discharge of clear water are not blanket permissions. The canton frames admissibility around water type and the receiving environment and identifies local permeability testing where actual infiltration capability must be determined. Do not treat a generic soakaway diagram or standard contractor detail as local approval. Ask who checks the current municipal and cantonal process, whether a submission or test is needed, and what document will confirm the decision. The answer can depend on site facts and destination; this article cannot decide it remotely.

The same applies to a sewer connection. Stormwater and wastewater are not interchangeable just because a pipe is nearby. Ask the contractor to identify the line, connection method, approval and person responsible for obtaining it. If the route cannot be verified without excavation, make that a separate diagnostic stage with a stop point before permanent works. A verbal “we always connect here” is not evidence that the particular pipe is suitable.

Property boundaries matter too. Vaud’s property information document describes a lower parcel’s duty to tolerate naturally flowing water and, under stated conditions, water from drainage of an upper parcel if it already flowed there naturally. That is a narrow contextual description, not a general permission to redirect water. Historic route, property facts and the actual intervention matter. When a project changes flow at a boundary, ask the relevant authority or a qualified legal professional about the actual situation rather than relying on a simplified summary.

What a useful contractor visit should produce

A useful visit leaves a shared problem definition. The contractor should point to the observed water path, separate observation from assumption, name the function of the proposed system and explain what would show the approach is wrong. A visit that produces only a product name and a price per metre may not yet give the owner enough information to approve the scope. Request a short written note before treating a permanent solution as certain.

The note should say what was inspected and what was inaccessible. It may honestly state that an outlet was visible but its downstream route was not traced, or that soil infiltration has not been tested. Ask whether drainage plans, utility information, prior repairs, approvals or neighboring changes were reviewed. A small garden issue does not always require formal engineering, but the scope should state which information supports the recommendation and which does not.

Ask what happens if excavation reveals a buried utility, unsuitable soil, groundwater, contamination, an unexpected pipe, unstable wall or outlet that cannot reach the assumed destination. The answer should define a stop-work and change-authorization process. “We will sort it out on site” leaves the owner unable to compare offers or control extras. Define who can approve changes, how price and time impacts are documented and how the open area is made safe if work pauses.

Ask for a proportionate handover: an as-built sketch, photos before backfill where practical, cleanout locations, outlet details, approvals, maintenance instructions and warranty terms. A future owner or repair professional should be able to understand where the system goes. The packet need not be elaborate for a small job; it should be sufficient to avoid reopening the same area just to rediscover a buried route.

Compare scopes before comparing totals

Offers are comparable only when they describe a similar outcome and boundary. A low price may omit outlet tracing, infiltration testing, paving restoration, spoil handling, wall protection or an as-built record. A higher figure may include those tasks. Neither total alone establishes value. Compare assumptions, included work, exclusions and promised checks before comparing the final amount.

For every offer, record the diagnosis, system function, route, destination, quantity basis, materials, access, reinstatement, waste handling, utility checks, approval responsibility, testing, maintenance, change rules and handover. Mark quantities fixed or provisional. If the scope depends on unknown soil or buried services, show the uncertainty as a staged investigation or provisional item. Do not hide it in a lump-sum promise that later turns into a disputed extra.

ECAS describes Swiss construction cost diagnostics as comparing proposed sums with cost analyses from completed projects and monitoring costs during design. That is a professional cost-control approach, not a public price list for garden drains and not a basis for inferring a particular Vaud job’s fair price. The transferable lesson is to define the comparison basis and keep assumptions visible. An independent cost or engineering professional may be proportionate for a complex or high-value project; for a small job, a clear written scope may suffice.

ETH Zurich’s “Renovating – yes! But how?” tool illustrates a related principle: renovation choices can be assessed across costs and environmental effects instead of reduced to a headline price. It does not design drainage. Apply the disciplined framing here: weigh water control, permission, maintenance, access, reinstatement, structural risk and retained evidence, not just trench length.

Scope question	Offer A	Offer B	Offer C
What water source is assumed?
What observation supports the assumption?
What is the system intended to do?
Where does collected water end?
Is the destination verified and suitable?
What test resolves important unknowns?
What work is excluded?
How are discoveries priced and approved?
What is restored and documented?

This is a comparison aid, not a score. Do not turn an unknown answer into a zero-cost assumption. If one contractor includes an infiltration test and another does not, first decide whether the test is necessary, then compare equivalent scopes. If one proposes pumping and another gravity flow, ask which observed condition explains the difference and what maintenance the pump adds. If offers use different destinations, they are not simply different prices for the same result.

A staged decision tree

flowchart TD
  A[Wet area observed] --> B{Rain-linked and surface flow visible?}
  B -->|Yes| C[Map source, path, grate and outlet]
  B -->|No or unclear| D[Record dry-weather persistence and emergence]
  C --> E{Existing route blocked or outlet unknown?}
  D --> F{Leak, spring, groundwater or structure concern?}
  E -->|Yes| G[Inspect or trace before new trench]
  E -->|No| H[Check grading and receiving constraints]
  F -->|Yes| I[Refer to utility, plumber or site specialist]
  F -->|No| H
  G --> J{Destination lawful and technically suitable?}
  H --> J
  I --> J
  J -->|Unknown| K[Pause irreversible work; resolve question]
  J -->|Supported| L[Compare written scope and failure response]
  L --> M[Authorize defined stage and retain as-built evidence]

The tree deliberately includes “pause.” That is a valid project decision when the missing fact could change the system. A short investigation may cost less than a trench with nowhere to discharge. The tree does not require every owner to collect every record before asking for advice; a professional can identify the next test. The owner’s job is to understand what decision the test supports and ensure permanent work is not silently bundled into diagnosis.

This is not a universal engineering standard. Active water entering a basement, undermined paving, movement in a retaining wall or a rapidly expanding wet area may require prompt specialist attention. Prioritize safety, use reversible protection and contact the appropriate service. Do not delay urgent action to complete the event card. The tool supports routine diagnosis; it cannot manage emergencies or predict structural behavior.

Original tool: the uncertainty ledger

The event card records what happened. The companion uncertainty ledger turns those observations into a controlled next action. Write each design dependency as a falsifiable statement, list what evidence exists, name the smallest safe check that could challenge it, identify the decision affected and set a stop condition. This is a worked model, not a measured dataset. It contains no invented performance percentages or local cost estimates and can be copied into a notebook or spreadsheet.

Assumption	Current evidence	Next check	Decision affected	Stop condition
Roof runoff feeds the wet strip	Strip starts below a downpipe during rain; outlet unverified	Observe the downpipe and trace accessible flow	Repair roof-water routing before a trench?	Stop if destination is unknown or affects another parcel
Soil accepts infiltration	No test; description is only verbal	Ask what in-situ test and siting review apply	Is a soakaway still an option?	Stop design if test or protection constraints fail
Existing pipe is suitable	Lid visible but downstream route unknown	Identify line through records or inspection	Gravity outlet or different destination?	Do not connect until identity and permission are verified
Structure is unaffected	Lawn is wet; no entry or movement recorded	Observe the building edge; seek specialist review if signs change	Urgency and discipline	Escalate for water ingress or movement
Work will not redirect water to a neighbor	Sketch suggests boundary flow could change	Review grades and route with the responsible professional	Route approval	Stop if boundary effects are unreviewed

An observation can support an assumption without proving it. “Water follows rain” supports a rain-related hypothesis but does not establish whether the cause is roof runoff, surface flow, saturated soil or groundwater. A useful check separates plausible explanations. Repeating an inspection without changing the decision is not useful. Conversely, if all plausible explanations lead to the same safe and permitted action, more testing may not justify its cost.

The stop condition prevents open-ended investigation. If an outlet cannot be located, pause before connecting. If an infiltration test does not support the destination, revisit the design. If an unexpected utility appears, stop until it is identified. This does not mean every discovery is predictable; it means the owner and contractor agree how uncertainty changes work, price and schedule before the garden is open.

Failure modes that make a plausible drain fail

No functioning outlet. A trench may fill and remain full if the outlet is blocked, disconnected or too high. Require a route drawing and evidence that the destination exists. If gravity is claimed, ask how the levels make it possible. If a pump is used, clarify power, controls, alarms and discharge. Without an outlet, the trench may be storage rather than drainage.

Wrong source. A buried drain may be installed when the issue is a downpipe, surface channel or irrigation leak. Keep event cards and ask whether the proposed explanation accounts for dry-weather behavior. If not, request the observation that would change the diagnosis before excavation.

Infiltration assumed. A soakaway can be unsuitable due to soil or site constraints. Vaud guidance links admissibility to water type and the receiving environment, and mentions local permeability, hazard zones and polluted sites. A generic detail does not establish those facts. Ask which rule applies and who confirms compliance.

Flow redirected to a building or neighbor. A channel can solve one puddle by creating another. Mark the before-and-after route on a sketch, especially near a boundary. Do not treat natural-flow rules as permission for a new concentrated discharge. Obtain site-specific advice where historical flow or ownership facts matter.

Filter or access omitted. Materials influence how sediment is handled; a system without access can be difficult to inspect. Ask what may clog, how it is cleaned and where a cleanout is located. A neat gravel strip is not automatically maintenance-free.

Discovery work unpriced. Excavation can reveal utilities, unsuitable ground, contamination, groundwater or an untraceable pipe. Define a stop-work process and who approves price or time changes. Otherwise a technically different solution may be accepted under pressure while the site is open.

Restoration and handover omitted. Paving, planting, spoil, temporary safety, surface levels and access affect the result. State what is restored and what evidence is retained before backfill. A future repair professional should not have to reopen the site merely to find the route.

One event mistaken for proof. A single storm is a clue, not necessarily a representative condition. Record naturally occurring events when safe, but do not delay action where damage is active. A homeowner log is not a hydrological study.

When a low-cost correction may be enough

Not every wet garden needs buried infrastructure. A visible blocked grate may need safe clearing; a disconnected downpipe may need its connection assessed; paving may be routing water into a low point; compacted lawn may need landscape advice. These are candidates to inspect, not universal recommendations. A reversible maintenance step is useful if safe and lawful and if it does not conceal a structural or contamination issue.

Record before and after and avoid changing several things at once if you want to learn what mattered. If ponding stops after clearing a grate, that is useful evidence but not proof that the full network will cope during heavier rainfall. If the symptom recurs or building impacts appear, reopen the diagnosis instead of scaling the same guess.

Nature-based measures can slow or retain water in some settings, but infiltration is not universally beneficial. Clay, slope stability, groundwater protection, contaminated land and available space may make it unsuitable. A garden measure should not transfer risk to a basement, water source, slope or neighbor. Ask which route fits the actual function and constraints and what maintenance the owner can perform.

When to involve another discipline

A landscape contractor may handle surface grading and accessible channels. A drainage specialist may be needed for pipe routing and existing networks. A plumber or utility provider may help with a suspected leak. A geotechnical engineer may be appropriate for slope stability, retaining structures, unusual ground or foundations. A municipal authority may clarify approvals and destinations. One professional may cover multiple roles, but the scope should state the responsibility being accepted.

Escalate promptly if water enters occupied space, undermines a foundation or retaining structure, causes visible movement, reaches electrical equipment or makes access unsafe. If there is immediate danger, follow local emergency procedures. Do not wait for several observations when consequences could be serious. For ordinary uncertainty, staged assessment reduces the chance of commissioning construction before knowing what problem it is meant to solve.

Give the specialist a sketch, dated photos, event cards, prior plans and repair records. Describe changes and what has already been tried. Keep raw observations separate from the first contractor’s theory. A neutral record allows a second opinion to assess the same facts rather than inherit a sales description.

A practical brief to request an estimate

We observed [specific wet area] on [dates or conditions]. Water first appears at [location] and seems to move toward [direction], but [uncertainty] remains. Attached are a parcel sketch and dated photographs. Please identify what you inspected, your likely source diagnosis and the evidence behind it. Before proposing permanent drainage, show the collection route and receiving point, explain how the destination will be verified and whether testing or approval is needed, and state what would make you stop or revise the design. Please separate diagnostic work from installation, list exclusions and restoration, and describe unexpected-condition changes, maintenance access and as-built handover.

This brief invites a diagnosis without telling the contractor what to install. If the contractor gives a direct recommendation, ask how it changes if the outlet is unavailable or infiltration unsuitable. If testing is unnecessary, ask what evidence makes the result sufficiently certain. If approval is irrelevant, ask which receiving point is proposed and who verifies that conclusion.

A contractor may reasonably say a site visit is required. That is a good answer when the visit has a defined purpose and does not imply automatic approval of later work. Ask whether the visit is free or chargeable, what deliverable it includes and whether diagnosis is quoted separately from construction. The aim is not to extract a full design without compensation; it is to know which decision the visit supports and what the owner receives.

How to interpret disagreement

Professionals can disagree because they saw different evidence or because a site has multiple water pathways. One may focus on surface runoff, another on soil infiltration, a third on building protection. Compare assumptions before choosing: did both inspect during similar conditions? Did one trace an outlet? Did one rely on an infiltration test? Did either account for neighboring flows or structures? Disagreement can expose the uncertainty worth resolving.

Do not average incompatible recommendations into a compromise trench. A middle depth or hybrid outlet may combine weaknesses. Ask each professional what observation would falsify the diagnosis and what risk the preferred route leaves. If both agree on the immediate safe action but differ on a permanent solution, consider a limited test, records search or independent assessment. If they assume different legal destinations, resolve that before comparing totals.

Also distinguish expertise from independence. A contractor can be competent and still have a commercial interest in the solution they install. An independent engineer or cost consultant adds another view and another cost; it may be proportionate for a complex site but unnecessary for a small, low-risk symptom. ECAS describes construction cost diagnostics based on completed Swiss project cost analyses and ongoing design monitoring. That is a cost-control service, not drainage diagnosis or a price list for one garden. Keep technical design review separate from commercial cost review.

Method, limits and responsible use

The event card and uncertainty ledger were written on 6 November 2026 as a reproducible documentation protocol for a homeowner decision: people may receive a product recommendation before they share a record of where water appears or where it can go. The eight event fields are a design choice, not a measured result. No property survey, contractor study, soil test or outcome sample was collected. This article therefore makes no performance rate, savings, price, or Vaud-wide prevalence claim.

The source review used the State of Vaud’s published infiltration guidance, the canton’s property information document for the limits of simplified boundary-flow statements, ETH Zurich’s renovation decision-support framing, and ECAS’s description of cost diagnostics. A homeowner discussion about wet gardens was reviewed for the practical concern of a drain without a verified destination. Forum accounts are individual experiences and cannot show what will work on a Vaud parcel. McKinsey’s city adaptation report describes a broader contradiction: nature-based infiltration measures can help in suitable settings, while clay soils, topography and local conditions can make them inappropriate. It is urban-scale analysis, not site design.

The protocol excludes hydraulic sizing, infiltration rates, rainfall return periods, legal opinions, contractor rankings and local cost estimates. It cannot tell a reader whether a parcel needs a permit, where an outlet may be located, whether a boundary flow is legally protected, or whether a structure is safe. Those decisions depend on site facts and current requirements. Verify the canton and commune process before work. If a professional identifies a question beyond their competence, engage the relevant specialist rather than stretching this guide into a design.

Facts, inference and recommendation

Sourced facts: Vaud says infiltration admissibility depends on water type and receiving environment and references in-situ testing of local permeability, along with hazards and polluted sites. ETH Zurich presents a renovation tool considering costs and environmental impacts; it is not a drainage calculator. ECAS describes diagnostics using completed construction projects and cost monitoring. These statements describe the cited material; they do not approve a particular property project.

Inference: If a design depends on an unknown source, outlet or soil condition, an owner may be comparing offers that solve different problems. Recording uncertainty before excavation can improve scope comparison and reveal which investigation changes the decision. This follows from the dependencies in the design; it has not been tested through an outcome study.

Recommendation: Record events, identify the water route and receiving point, then request a staged written scope. Pause irreversible work when destination, infiltration suitability or approval is unresolved. Escalate for structural symptoms, suspected leaks, groundwater questions or legal boundary concerns. This is a homeowner process recommendation, not site-specific professional advice.

Checklist before excavation

• [ ] I can describe the wet area more precisely than “bad drainage.”
• [ ] My sketch shows structures, slope, boundary, visible flow and unknown routes.
• [ ] Observations are separated from suspected causes.
• [ ] I know whether the symptom follows rain, irrigation or dry weather, or have marked the unknown.
• [ ] Photos show context and detail; visible grates and outlets were observed safely.
• [ ] The contractor stated the source and system function assumed.
• [ ] The route and receiving point are shown and will be verified.
• [ ] The contractor explained whether a test, approval or authority confirmation is needed.
• [ ] Exclusions, reinstatement, access, spoil, utilities and discovery work are addressed.
• [ ] A stop-work and written change-approval process is in place.
• [ ] Handover includes useful as-built information and maintenance access.
• [ ] I know which symptoms require another specialist or urgent response.

Several unchecked boxes do not prove the contractor is unqualified or the project unsafe. They indicate that the owner should clarify what is a prerequisite and what can be confirmed during a defined first stage. A maintenance visit may need less documentation than excavation beside a foundation or connection to a public network. The goal is proportional clarity, not paperwork for its own sake.

Bottom line

A waterlogged garden shows a water-management problem; it does not prove that a French drain is the answer. Record when and where water appears, identify the source and path as far as safely possible, and put the destination at the center of the conversation. Vaud’s infiltration guidance makes clear that water type, receiving environment, local soil and site constraints matter. A visible outlet, generic trench detail or verbal promise cannot replace that check.

Use the event card and uncertainty ledger to turn “the garden stays wet” into a specific question for a contractor or authority. Compare written scopes by assumptions, route, approval, exclusions and failure response before comparing totals. When evidence supports a lawful, maintainable correction, authorize a defined scope and retain a useful handover record. When crucial facts remain unknown, stage the investigation and pause irreversible work. That is a sound outcome: diagnosis is meant to select the right next decision, including not digging yet.

Sources

• State of Vaud: infiltration of unpolluted water
• Vaud property information document
• ETH Zurich: “Renovating – yes! But how?”
• ECAS: Construction Cost Diagnostics
• McKinsey: Focused adaptation in cities
• Homebuilding: garden drainage and French drains

The FTC’s U.S. home-improvement consumer guide recommends written estimates that identify work, materials, timing and price, and advises consumers to retain records. This is a cross-check for the article’s documentation approach only; its legal rights, cancellation rules and licensing guidance concern U.S. jurisdictions and do not apply as Vaud law. The agency’s business guidance portal provides broader U.S. business material, not a source for Swiss construction requirements.

Copyable event-card CSV header

For a spreadsheet or a simple CSV log, copy this header and create one row per event. The fields correspond to the card above. The example intentionally contains no sample observations; owners should enter their own dates and avoid recording a cause as fact until observed.

event_date,start_time,duration,rain_or_irrigation,wet_footprint,first_visible_water,flow_direction,nearby_inputs,building_effect,existing_route,route_confidence,recent_change,open_question,photo_files

Keep photographs outside the CSV and refer to filenames in the final column. Do not store sensitive neighbor information unnecessarily; a parcel sketch can show direction without identifying people. If a professional needs exact elevations, ask them to define a survey or measurement instead of treating this homeowner log as one.