Urban

Urban Stormwater Management in Arran-Elderslie

Arran-Elderslie’s urban stormwater system is extensive, with approximately 30 kilometres of storm sewer infrastructure, equal to the distance from the south end of Chesley to Highway 21 in Allenford. The three urban centres—Chesley, Paisley, and Tara—collectively manage a drainage area of about 900 acres, roughly the size of a country block. This network includes 1,053 stormwater structures, such as catch basins and manholes, designed to protect properties and waterways during heavy rainfall. The estimated cost to replace the entire system on a like-for-like basis, without enhancements, is approximately $31 million, underscoring the importance of proactive maintenance and long-term planning to ensure reliable service for our community.

Understanding Stormwater

Stormwater is the water that originates from rainfall, snowmelt, or other forms of precipitation and flows over land surfaces. In natural environments, most stormwater is absorbed into the ground. But in urban areas, where surfaces like roads, rooftops, and sidewalks are impermeable, stormwater runs off into drainage systems.

Storm Water Systems

Minor Stormwater Systems

In general, catch basins collect stormwater runoff and carry it through storm sewers to a dedicated outlet. Such runoff transportation network is termed as the “minor stormwater system”. The minor stormwater system is generally intended to carry runoff from a 1:2-year or 1:5-year storm event.

Major Stormwater Systems

For larger storms, the excess stormwater runoff that cannot be conveyed by the minor system is carried overland, usually in road corridors and ditches, to a dedicated outlet. This is referred to as the “major stormwater system”.

Why Stormwater Matters

Manages Rainfall and Runoff

Stormwater systems help handle large volumes of rain and snowmelt, preventing water from pooling on streets and properties.

Prevents Urban Flooding
Without proper stormwater management, heavy rains can overwhelm streets, homes, and businesses—leading to costly damage and disruptions.

Protects Water Quality
Stormwater can carry pollutants like oil, pesticides, and litter into rivers and lakes. Managing it properly helps reduce contamination and protect aquatic ecosystems.

Supports Green Infrastructure
Modern stormwater strategies often include rain gardens, permeable pavements, and bioswales, which enhance urban green space and biodiversity.

Builds Climate Resilience
As extreme weather events become more common, effective stormwater systems help communities adapt and reduce the impact of storms and flooding.

What are Storm Return Periods

A storm return period is a statistical measure used to estimate how often a storm of a certain intensity is likely to occur. It’s commonly used in engineering, urban planning, and flood risk management.
1:2 Year Storm→ 50% chance per year
1:5 Year Storm→ 20% chance per year
1:10 Year Storm→ 10% chance per year
1:100 Year Storm→ 1% chance per year

Important Notes
• It’s a probability, not a prediction. A 100-year storm can happen more than once in 100 years.
• It’s based on historical data, which may not reflect future conditions—especially with climate change.
• Used to design infrastructure like storm sewers, culverts, and flood defenses to withstand specific storm intensities.

Sewer Surcharging vs. Flooding

Storm sewer surcharging occurs when the stormwater system becomes overwhelmed and the water level inside the sewer pipes rises above the normal flow level, often reaching or exceeding the top of the pipe. This typically happens during heavy rainfall events when the volume of water entering the system exceeds its design capacity.

Key Characteristics of Surcharging:
• Water backs up in the pipes and may rise into connected catch basins or manholes.
• It does not necessarily cause surface flooding, but it indicates the system is under stress.
• If surcharging is severe or prolonged, it can lead to localized flooding, especially in low-lying areas.
• It’s a sign that the system may need upgrades to improve capacity or flow efficiency.

Storm sewer flooding occurs when the stormwater system becomes overwhelmed and water escapes from the sewer network onto the surface. This is different from surcharging, where water rises within the system but hasn’t yet escaped to the surface. Flooding is the next stage—when the system fails to contain the water entirely.

This typically happens during intense rainfall events when:
• The volume of water exceeds the system’s capacity.
• Pipes and catch basins are blocked or undersized.
• Water cannot drain quickly enough, causing it to back up and overflow.

Effects of Storm Sewer Flooding:
• Water may pool on roads, sidewalks, and private properties.
• It can lead to property damage, traffic disruptions, and safety hazards.
• In severe cases, it may contribute to basement flooding or erosion.

Urban Stormwater Needs Studies

The Municipality hired GSS Engineering to conduct a Stormwater Needs Study for Chesley, Paisley, and Tara. The study evaluates current stormwater systems, identifies capacity deficiencies, and recommends targeted upgrades to reduce flooding during 1:5-year storm events, while acknowledging that eliminating all overloading may not be feasible or affordable. The report assesses infrastructure, prioritizes improvements, estimates costs, and aims to help Arran-Elderslie make informed decisions for effective and sustainable stormwater management.

Chesley Stormwater Needs Study

Paisley Stormwater Needs Study

Tara Stormwater Needs Study

As of January 1, 2026, urban stormwater management will be supported through a utility model that introduces a levy on users of the urban stormwater system to create a dedicated fund for constructing, operating, and maintaining stormwater infrastructure within the urban centres of Chesley, Paisley, and Tara. This shifts the financing for stormwater-related expenses away from general taxation and aligns it with how water and sanitary sewer infrastructure currently is funded.

The utility levy applies to users of the urban stormwater system and introduce service levels that establish and maintain curb and gutter along all urban streets, eliminating open ditches.

Below are some documents related to creation of the stormwater utility.

Level of Service - Streetscape Rendering Video

Public Information Session Presentation - Building a Resilient Future: Establishing a Stormwater Utility

July 14 Council Presentation from Hemson Consulting

July 14 Council Meeting

Sept 22 Council Meeting

October 14 Council Meeting

October 27 Council Meeting

November 24 Council Meeting - Passing of By-Law

WHEREAS sections 8, 9 and 10 of the Municipal Act, 2001, S.O. 2001, c.25, as amended, authorizes the Municipality of Arran-Elderslie to pass by-laws respecting public assets of the municipality acquired for the purpose of exercising its authority under the said Act or any other Act and respecting services the municipality considers necessary or desirable for the public, including the provision of public utilities such as water and sewage as defined in the Municipal Act, 2001;

WHEREAS subsection 391(1) of the Municipal Act, 2001 provides that sections 9 and 10 of that Act authorize a municipality to impose fees or charges on any class of persons for services or activities provided or done by or on behalf of the municipality and for the use of the municipality’s property, including property under its control;

WHEREAS subsection 391 (3) of the Municipal Act, 2001 provides that the costs included in a fee or charge may include costs incurred by the municipality or local board related to administration, enforcement and the establishment, acquisition and replacement of capital assets;

WHEREAS the Municipality is operating and maintaining a stormwater management system for the benefit of residents and business property owners within the urban centres of Chesley, Paisley and Tara;

WHEREAS the Council of the Municipality of Arran-Elderslie deems it necessary and desirable to maintain a dedicated funding option for the long-term sustainability and enhancement of its existing urban stormwater management system within the urban centres through effective and efficient capital construction, operation and maintenance programs;

WHEREAS the creation of a separate stormwater charge to fund such urban stormwater management program will bring transparency to the actual costs of providing and maintaining the urban stormwater drainage system;

WHEREAS it is deemed just that the cost of administering, operating, maintaining and upgrading the urban stormwater management system is paid for by those who benefit from the system;

NOW THEREFORE the Council of the Municipality of Arran-Elderslie enacts as follows:

PART 1 – DEFINITIONS

1. In this By-law,

“Business Park” means a property zoned:

· BP1 - Business Park 1

· BP2 - Business Park 2

“Commercial” means a property zoned:

· C1 – Central Business District Commercial

· C2 - Transition Commercial

· C3 - Highway Commercial

· C4 - Large Format Commercial

“Council” means the elected Council of the Municipality of Arran-Elderslie.

“Institutional” means a property zoned:

· IN - Institutional Zone

“Multi-Residential” means a property zoned:

· R3 – Residential: Medium Density

· MU – Mixed Use

“Semi-Detached” means a property zoned:

· R2 – Residential: Low Density Multiple

“Single Detached” means a property zoned:

· R1 – Residential: Low Density Single

“Stormwater Charge” means the Municipality’s stormwater fees and charges in respect of the Urban Stormwater Management System, as listed in Schedule “A” and imposed pursuant to ss. 9 and 10 and Part XII of the Municipal Act, 2001;

”Urban Stormwater Management System” refers to stormwater system within the urban centres of Chesley, Paisley and Tara and means the infrastructure or measures used, controlled, maintained or operated by the Municipality to manage stormwater flow and drainage systems and all appurtenances thereto owned, and includes, but is not limited to, storm sewers, catch basins, storm service connections, drains, pipes, outfalls, overland conveyance systems including road corridors, culverts, channels, ditches, swales, dykes, rivers, streams, creeks and watercourses, stormwater management facilities including landscaping and low impact development features, storage ponds or underground tanks, and oil and grease treatment devices that control quantity or quality of stormwater runoff, pumping stations and all equipment laid within any highway or road allowance, Municipality right- of-way or easement or Municipality property used for the collection, transmission, detention and treatment of stormwater or uncontaminated water;

PART TWO - IMPOSITION OF CHARGE

2.1 A Stormwater Charge shall be imposed upon all property owners in the Municipality that are connected to the municipal water and/or sanitary sewer system, namely those located within the urban centres of Chesley, Paisley and Tara.

2.2 Stormwater charges shall be determined by the property zoning in accordance with the Arran-Elderslie Comprehensive Zoning By-Law, as amended from time to time, and property size in square metres as per the Bruce County Geographic Information System.

2.3 Where a property's zone is undefined or disputed, the determination will be made in accordance with the Arran-Elderslie Comprehensive Zoning By-Law, in consultation the Municipal Zoning Administrator.

2.4 The Stormwater Charge shall be in accordance with the Stormwater Rate Structure set out in Schedule “A” to this By-law.

2.5 The Stormwater Charge shall have priority lien status under Section 398(2) of the Municipal Act, 2001.

2.6 The Stormwater Rate Structure set out in Schedule “A” to this bylaw shall be subject to a 2.4% inflationary increase in year 2027, 2028, 2029, 2030, 2031, after which, the increases will follow the Arran-Elderslie Financial Plan for water, sanitary sewer and stormwater.

PART THREE - ADMINISTRATION

3.1 The Municipality of Arran-Elderslie is hereby authorized to collect the Municipality’s Stormwater Charges annually through the property tax bill in accordance with the Stormwater Rate Structure set out in Schedule “A” to this by-law subject to any increases in accordance with section 2.6 above.

3.2 On or before February 1st of each year, the Municipality will undertake a verification of the property zoning and square metre area all properties within the Urban Stormwater Management System.

3.3 All revenues generated through the Stormwater Charge and collected in accordance with section 3.1, shall be allocated to a dedicated stormwater reserve which is hereby deemed to be 01-0000-7234 – Stormwater.

3.4 The stormwater reserve shall be used to fund the on-going administration, operation, maintenance and capital expenditures associated with the Urban Stormwater Management System.

3.5 Any decision or determination required to be made by the Municipality or any official of the Municipality under this By-law shall be made in the sole and absolute discretion of the Municipality or the Municipality official.

3.6 This By-law shall be known as the “Stormwater Charge By-law”.

3.7 This By-law comes into force on January 1, 2026.

Read a first and second time this 24th day of November 2025.

Read a third time and finally passed this 24th day of November 2025.

Original Signed By Original Signed By

_________________________ __________________________

Mayor Steve Hammell Clerk – Christine Fraser-McDonald

Schedule “A” to By-Law 84-2025

Stormwater Rate Structure

1. The following rates are hereby imposed for the year 2026 and shall be applied to properties in accordance with section 2.1 of the bylaw.

2. Following year 2026, the rate shall be subject to inflationary increases in accordance with section 2.6 of the bylaw.

Property Type	Rate per Square Metre
Single Detached	$0.1117
Semi-Detached	$0.1117
Multi-Residential	$0.1421
Commercial	$0.2234
Business Park	$0.2234
Institutional	$0.2234

The Stormwater Utility ensures sustainable funding for the maintenance and improvement of our stormwater infrastructure, which protects homes, businesses, and waterways from flooding and pollution. Funds collected through this program are dedicated exclusively to stormwater services, including inspections, repairs, and upgrades.

The annual contribution rate for each property is calculated using the property size in square metres and the property type. This amount is added to the property tax bill and divided amoungst the four tax installments throughout the year.

The annual median bill for a residential property is approximately $103.00. This amount will vary by property based on size and property type.

The 2026 Rate Structure is as follows:

Property Type	Rate per Square Metre
Single Detached	$0.1117
Semi-Detached	$0.1117
Multi-Residential	$0.1421
Commercial	$0.2234
Business Park	$0.2234
Institutional	$0.2234

Municipality of Arran Elderslie
1925 Bruce Road 10, Box 70
Chesley ON, N0G 1L0

Phone: 519-363-3039
Fax: 519-363-2203