Ground conditions on the Oceanside coast
Parksville Excavating works ground that runs in glacial layers, stacked across Oceanside in a fairly predictable order — sand and gravel near surface, Vashon till underneath and Quadra Sand below that. The Quadra Sand unit averages around 19 metres thick across the Nanaimo Lowland, so we treat a cut near Parksville and a cut at Errington as two different jobs.
Updated September 2026
We can't price your job from the street. Most of what sets your price is under the ground. The coastal strip between Nanoose Bay and Qualicum Beach sits on a stack of glacial deposits laid down in a repeatable sequence, and knowing where a lot sits in that stack is most of knowing how it will dig.
The stack, top to bottom
Dig down here and you go through the same layers in the same order. Under your topsoil we hit recent fluvial Salish sediments, then around two metres of Capilano and Salish sand, then roughly four metres of fine-grained Capilano glaciomarine material, then about eight metres of coarse glaciofluvial sand and gravel. Below that we find Vashon till, a dense sandy material averaging around twelve metres. Under the till we reach the Quadra Sand at around nineteen metres, a well-sorted sand that is the principal aquifer of the lowland. Deeper again you have the Cowichan Head and Dashwood silts at about sixteen metres, and the Dashwood–Mapleguard sands at around nineteen.
Your lot won't match those depths exactly. What does hold is the order, and that's what we plan a cut around. When the digging suddenly gets slow, we've usually hit the till. It stands up almost straight and it's hard work to get through.
Where the bedrock comes up
The bedrock under all of it is the Nanaimo Group — Comox Formation sandstone and conglomerate, roughly 100 to 150 metres thick, over Haslam Formation shale of similar thickness, sitting on Wrangellia basement rock.
We find bedrock at very different depths here, and that separates the coastal lots from the inland ones. Around Errington the Haslam shale is close enough to surface that it is mapped as the aquifer itself, fractured rather than porous, and a cut there can turn from digging into breaking within a metre. That single fact changes machine class, day rate and duration, so we don't book the machine until we know the ground.
Water in the ground
We look at depth to the water table before we look at soil type, because it matters more to a deep excavation. Around Nanoose Bay seasonal fluctuation runs from under half a metre to about three metres in the overburden aquifers, and from one to eight metres in the bedrock units, so the same detail on the same lot behaves differently in February than in August.
The type of ground matters as much as how deep it sits. French Creek sits on a small unconfined deltaic aquifer of Salish sand and gravel, high productivity and high vulnerability, with no confining layer between the surface and the water table. Parksville and Qualicum Beach both sit on confined Quadra Sand, where a till layer sits between the surface and the aquifer.
The Regional District of Nanaimo measures these directly. Its June 2026 analysis put the Parksville aquifer within normal with an increasing trend, the Oceanside bedrock aquifer much above normal, the Qualicum Beach and French Creek surficial aquifers much below normal with stable trends, and the Errington bedrock aquifer below normal.
| Aquifer | Area | Material | Productivity | Vulnerability |
|---|---|---|---|---|
| 216 | Parksville | sand and gravel, confined glacial | moderate | moderate |
| 217 | Qualicum | sand and gravel, confined glacial | moderate | moderate |
| 220 | Errington | bedrock, fractured Haslam shale | low | moderate |
| 1248 | French Creek | sand and gravel, unconfined deltaic | high | high |
| 662 | Big and Little Qualicum | sand and gravel, confined glacial | moderate | low |
BC Groundwater Wells and Aquifers database, mapping updated 2023. Groundwater level classifications from the Regional District of Nanaimo Regional Groundwater Level Analysis, 23 June 2026.
What each layer changes about the work
In sand and gravel we dig fast, but the sides won't stand. We cut them back, so your hole ends up wider and that's more material moved.
In till we're slower, but the sides hold. We plan the schedule around machine class there rather than volume, and a mini that was fine for the topsoil strip is no longer the right tool.
In the fine grey material water barely moves, so we spend the time on where your drain lets out rather than on the pipe itself.
In shale we're breaking rock, which is a different job and a different price. Once we are into rock, how much of it there is matters far less than how we get through it.
Rain and the working year
The reference station for this watershed, at Coombs, records around 1,126 millimetres a year, and the majority of it falls between October and March. Higher ground in the Englishman River watershed takes considerably more.
That's why we can hold a date more easily for deep cuts, driveway build-ups and anything needing compaction in the drier months. Work still happens through the winter; it just needs the drainage thought through first rather than added afterwards.
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