London flood prevention - property owner bylaw guide

London, Ontario property owners must take practical steps to reduce flood risk on private land and around their building envelope. This guide explains municipal responsibilities, common prevention measures, reporting routes and how local bylaws and conservation authority rules affect landscaping, drains, sump pumps and structural changes. It summarizes actions to prepare before heavy rain, what to do during flooding and how to work with City of London and conservation staff to reduce future risk. Follow the links to official sources for emergency warnings, stormwater information and permit requirements.

Common prevention steps

Start with property-level measures and documentation so you can act quickly and show compliance if inspected. Typical steps include:

• Check and maintain eavestroughs and downspouts; ensure downspouts discharge at least 1.5 m from the foundation where possible.
• Install or test a battery-backed sump pump and a one-way backflow valve on sewer connections where allowed.
• Document elevations, grading and any drainage changes in photographs and simple sketches for permit or insurance purposes.
• Keep a maintenance schedule for gardens, retaining walls and patios to prevent blocked overland flow paths.

For guidance on stormwater management and City-recommended practices, consult the City of London stormwater and flooding pages City of London flood and stormwater information^[1] and the local conservation authority for flood forecasting and mapping Upper Thames River Conservation Authority flood information^[2].

Penalties & Enforcement

Responsibility for enforcing flood-related restrictions typically falls to City of London By-law Enforcement, Building Services and the Upper Thames River Conservation Authority for regulated floodplain activities. Specific penalties and escalation for contraventions should be confirmed on the cited official pages; where amounts or escalation rules are not shown on those pages the text below notes that fact.

• Fines: not specified on the cited page; check the City of London bylaws and enforcement pages for exact dollar amounts and schedules.
• Escalation: first, repeat and continuing offence procedures are not specified on the cited page; standard practice may include tickets, increased fines and court proceedings.
• Non-monetary sanctions: municipal orders to remedy drainage or alterworks, stop-work orders, demolition or removal orders, and court enforcement are possible where contraventions affect public safety or drainage.
• Enforcer and complaints: City of London By-law Enforcement and Building Services handle private-property drainage and permit compliance; floodplain and regulated works are enforced by the Upper Thames River Conservation Authority UTRCA flood information^[2].
• Appeals and review: appeal routes depend on the specific order or ticket; time limits are not specified on the cited page—refer to the issuing body for review deadlines.

Applications & Forms

• Building permits: required for structural changes that affect grading or roof drainage; see City of London Building Services for application details.
• Conservation authority approvals: works in regulated areas may need UTRCA permit applications; check the UTRCA for application forms and submission instructions.
• Fees and deadlines: fees and deadlines vary by application type and are listed on the issuing agency pages; if a form or fee is not published, it is not specified on the cited page.

How to respond during heavy rain or flooding

Take immediate steps to protect people and property, then report damage and follow official warnings.

1. Move valuables and electrical items above expected flood level and shut off power if safe to do so.
2. Report active flooding or blocked municipal drains to City of London services during business hours or emergency lines after hours; consult official city pages for the correct contact.
3. After immediate risks pass, document damage with photos and contact your insurer and the issuing municipality or conservation authority for guidance on remediation and permits.

FAQ

Who enforces flood-related rules in London, Ontario?

City of London By-law Enforcement and Building Services enforce municipal bylaws; the Upper Thames River Conservation Authority enforces regulations for regulated floodplain areas and issues approvals where required.

Do I need a permit to change grading or add a retaining wall?

Structural changes that affect drainage or are within regulated areas often require a building permit and possibly a conservation authority approval; check the City building permit page and UTRCA permit requirements.

How do I report a blocked storm drain or basement flooding?

Contact City of London service or emergency lines as directed on the city website and follow conservation authority flood warnings if active.

How-To

1. Inspect your roof, gutters and downspouts and remove debris to ensure free flow.
2. Install or test a sump pump and backflow valve where appropriate and permitted.
3. Before changing grading, consult City of London Building Services for permit requirements and contact UTRCA if your property is in a regulated area.
4. Store documentation and photos of drainage conditions and permit approvals to support compliance and any insurance claims.

Key Takeaways

• Maintain gutters and direct downspouts away from foundations to reduce basement flooding.
• Check permit and conservation authority requirements before altering grading or working in a floodplain.

Help and Support / Resources

• City of London report a problem / service request
• City of London Building Services and permits
• City of London By-law Enforcement
• Upper Thames River Conservation Authority (UTRCA)

1. [1] City of London flood and stormwater information
2. [2] Upper Thames River Conservation Authority - Flood information