Section 01
Establishing whether the constraint applies at all
The first task is to determine whether the parcel is within the area the City's valley and ravine guidance addresses. Proximity is not obvious from a listing photograph: a house with a ravine view across a road may sit outside the constrained area, while a house with no view at all may sit directly above a bank behind a fence line.
Confirm the parcel's relationship to the valley or ravine and to the top of bank with the City, and where the answer matters to a purchase or a project, with a surveyor and a geotechnical engineer. Everything else on this page is contingent on that answer being yes.
Section 02
Separation and the top of bank
The City states that as part of protecting the valley and ravine system it requires separation between any development and the abutting valley or ravine, and directs owners to the Top of Bank Policy. That separation is a planning constraint on where development may occur relative to the bank, and it is determined for a specific parcel rather than read off a general description.
For an owner planning an addition, a detached structure, a deck or a pool, the separation question comes before the design question. A concept drawn first and tested afterwards is how valley-adjacent projects lose a year.
Section 03
Permits for grade change and water retention
The City sets out owner responsibilities that include obtaining required permits and approvals before any construction or removal of a structure, and before commencing any landscaping activity that alters the existing grade and natural surface drainage pattern of the property. That sweeps in work owners often treat as landscaping rather than development.
Water retention structures — swimming pools, skating rinks, ornamental ponds, hot tubs, cisterns, septic tanks and other water and wastewater retention structures — are identified as discretionary developments requiring a valid development permit, subject to review of the necessary geotechnical reporting. The geotechnical report is part of the approval pathway, not an optional second opinion.
These requirements attach to parcels near or beside the valley and ravine system. Confirm applicability for the specific address before planning any work.
Section 04
Water practices the City asks owners to avoid
Beyond permits, the guidance identifies practices owners near the valley should avoid: excessive watering of lawns, trees, shrubs and other vegetation; installation of granular or rock landscaping that can focus infiltration; altering the grade or adding fill; disturbing natural vegetation; and installing or using geothermal loop systems below ground.
The City also limits hard surfacing in rear and side yards to a stated area per yard, with the remainder landscaped in permeable materials. For a buyer, that list doubles as an inspection checklist for what a previous owner may already have done to the property.
Section 05
Documented and not documented on a valley-adjacent lot
Documented, potentially: development and building permits for structures and site work, any geotechnical reports commissioned for a previous approval, grading records, and the survey with its City Compliance Certificate Report showing where structures actually sit.
Not documented, usually: current slope stability. A historic geotechnical report describes conditions and assumptions at the date it was written for the project it was written for. It is not a warranty of the bank's behaviour today, and it is not transferable in effect merely because it is transferable in paper.
Section 06
Before-offer and pre-construction sequence
Before an offer: confirm the parcel's relationship to the valley system and top of bank, obtain the survey and read where structures sit relative to the bank and to any environmental reserve, search title for registrations affecting the rear of the lot, ask what permits and geotechnical reports the seller holds, and ask a geotechnical engineer what the site conditions warrant.
Before construction: settle applicability and separation, commission the geotechnical work the City's workflow requires, design drainage and irrigation to move water away from the bank, and treat pools, ponds, hot tubs and buried tanks as development permit items from the first sketch rather than as landscaping to be added later.
Section 07
Escalation triggers
Engage a geotechnical engineer where any grade change, water retention structure, excavation or retaining work is contemplated, and where movement, cracking, seepage or tension cracks in the yard are visible. Engage a land surveyor to establish the bank relationship on the ground. Engage a lawyer where an environmental reserve, an easement or a caveat touches the rear of the parcel.
Engage the City early, because the discretionary nature of these developments means the conversation shapes the design rather than merely approving it. Nothing on this page assesses the stability of any slope or the suitability of any project.
Slope conditions are parcel specific. No general guidance, including this page, can substitute for site-specific geotechnical advice.