Published and sources reviewed: October 5, 2026. A rain garden can help manage roof and surface runoff, but choosing a low spot is only the start. Use these checks to prepare a site-specific plan.
1. Identify the water source and existing outlet
Sketch the roof areas, downspouts, paved surfaces and visible drains. Record where water travels during rain from a safe position. Before disconnecting a downspout, establish where its current pipe leads and what an alternative discharge would affect. If a connection is unknown, discuss investigation with a drainage contractor first.
A rain garden manages runoff; it does not establish whether buried perimeter drains are sound. If water reaches the house, compare the evidence for surface-water changes and perimeter drain repair before choosing either.
2. Check location and soil before choosing plants
The RDN-hosted rain-garden handout (May 2018) advises avoiding steep slopes, flood-prone locations, foundations, septic beds and neighbouring homes. It also ties the garden’s size to incoming water and absorption. These are screening questions, not a universal setback or excavation depth.
The RDN demonstration garden illustrates why the ground matters: its earlier turf-covered, compacted soil limited infiltration. The RDN describes soil and planting improvements completed in May 2024. This is the RDN’s example, not a Fairytale project. Ask how your proposed location’s infiltration and seasonal wetness will be assessed before ordering materials.
3. Plan for water that exceeds the garden’s capacity
Ask where overflow will go when the garden is full or the soil is already wet. Show nearby doors, foundation edges, slopes, property boundaries and any retaining wall on the sketch. Confirm a suitable discharge arrangement before connecting or changing anything. A low area that collects water needs an overflow plan as well as an infiltration plan.
Make utility identification, access and excavation limits part of planning. Do not excavate beside a foundation or supporting structure on the assumption that a shallow-looking feature is harmless. Use a site-specific assessment where the proposed work affects support or an existing drain.
4. Separate household maintenance from public drainage work
The City of Nanaimo’s homeowner guidance, updated September 15, 2026, recommends keeping leaves and debris off catch basins and keeping yard waste out of ditches. Clear surface debris only where access is safe; avoid traffic and flowing water. The City says not to clear culverts yourself: contact Public Works at 250-758-5222.
Outside City boundaries, do not assume the same department maintains the roadside ditch. RDN drainage guidance explains that provincial, regional and private responsibilities differ. Establish who manages the receiving system before proposing changes. Keep soil, concrete washwater and other waste out of storm drains.
5. Keep a useful rain-event record
For the next event, note the date, time, first pooling location, visible downspout behaviour and how long water remains after rain stops. Take comparable wide photos from safe ground. Bring that record, a site sketch and previous repair information to an assessment. An airport weather observation provides regional context; it does not measure rainfall or diagnose damage at your home.
Bring the plan to a paid diagnostic visit
Fairytale’s residential diagnostic audit is $450, including 1.5 on-site hours; extra time is $150/hour. The pre-purchase inspection is $650. Flush-and-inspect is $950–$1,250, with specialized support when needed. Suitability, scope and charges are confirmed before booking; a rain-garden design or excavation scope is discussed separately.
Start with an inspection plan
Tell Clayton what you have noticed and send property photos. Camera inspections and technical investigations are paid services; suitability, scope and charges are confirmed before booking.
Request a camera inspection