Maintenance, Rehabilitation and Repair

A Stormwater Tree Trench located on a municipal boulevard in need of general maintenance (Photo Source: Contech Engineered Solutions, 2021).

Overview

The desired level of service for an individual BMP or an entire inspection and maintenance program encompasses the frequency and type of inspection and maintenance activities that will be undertaken. For example, will BMP inspections be done on an annual basis or more frequently for high priority/visibility ones? Will this vary based on the size and type of BMP, whether the practice is on public or private land, or other factors such as implications if treatment performance is not maintained (e.g., within drainage areas of sensitive receiving waters or species at risk habitat)? Will maintenance be performed in response to complaints or emergencies or will it be based on preset schedules and findings from routine inspections? The table below outlines several key level of service decisions that need to be made by a municipality prior to program design and is intended to help managers of stormwater infrastructure with planning for the future as their programs develop and evolve.

Level of Service for Municipal Stormwater BMP I&M Program

Level of Service	BMPs Included	Maintenance Tasks	Maintenance Frequency	Inspectors	Inspection Frequency	Feedback from Experience
	BMPs on public land and within rights-of-way	Repair immediate threats to public health and safety	React to complaints and emergencies	Rely on owners/ managers or their contractors to inspect, maintain and keep track of records.	Complaint driven	Anecdotal
	+	+	+	Inspectors send reports to responsible party and municipality	Annual or semiannual	+
	High priority, high visibility, and/or large BMPs on private land within easements and covered by agreements	Repair structural items: clogged or broken parts, erosion problems	Establish preset schedule for routine inspection and maintenance tasks	Co-inspections with public inspector and responsible party or their consultants	More frequent for high priority BMPs	Feedback used to modify list of acceptable BMPs based on maintenance or performance record
	+	Routine mowing, weeding, remove trash and debris, replace vegetation; and, (+)	+	Periodic Maintenance and Performance Verification inspections	Maintenance Verification inspections every 5 years	+
	All or most BMPs on private land within easements and covered by agreements	Includes retrofitting or reconstructing BMPs; and, (+)	Conduct structural repairs in response to Routine Operation, Maintenance and Performance Verification inspections	System of certified private inspectors	Performance Verification inspections every 15 years	Feedback used to modify municipal programs and BMP design guidance or standards
	Note: (+) denotes s that services are cumulative (level of service includes all previous tasks too).

Responsibility of Maintenance Tasks

Check out the table below that highlights more examples of the differences between routine and structural maintenance tasks. One option for municipalities is to assign responsibility for routine maintenance tasks that are largely aesthetic in nature to the property owner while retaining responsibility for structural repairs. As municipal programs become more sophisticated, some routine maintenance tasks like sediment removal may be taken over by the municipality to avoid or prolong the need for more costly structural repairs.

Routine Maintenance Vs. Structural Repair Tasks

Routine Maintenance Tasks	Structural Repair Tasks
Mowing, trimming, weeding vegetation Removal of trash and debris Replacing individual dead plants, seeding bare spots Core aeration Removal of sediment and debris accumulated in pretreatment practices, inlets or outlets Flushing pipes	Unclogging inlets, pipes, catchbasin sumps, filter beds, outlets Repairing or replacing broken or missing parts (e.g., pipes, wells, grates, manholes, valves, seals, pavements, curbs) Regrading to remedy extreme soil erosion or sedimentation Replacing large quantities of failed plantings, filter media or topsoil

Responsible Parties

Large municipalities and property management organizations with numerous properties and BMPs to maintain may choose to use in-house staff to conduct BMP maintenance. However, for small to medium-sized organizations, employing private contractors is often more efficient than hiring new staff and purchasing equipment. Another option is entering into an agreement with neighboring local municipalities, the upper-tier municipality or other property managers with stormwater BMPs to maintain to share responsibilities and maximize economies of scale in the use of equipment and personnel.

Tracking, Verifying & Enforcing Maintenance Requirements

For municipalities, enabling policies and program tracking and evaluation systems are key components of an effective stormwater BMP inspection and maintenance program. Before a development proposal is approved, each BMP in the SWM plan that contributes to meeting regulatory requirements should at a minimum, have an inspection and maintenance plan prepared and included in submissions for plan review and approval. Ideally, each BMP that contributes to meeting regulatory requirements should be part of an ECA or maintenance agreement that includes inspection and maintenance plans specific to each type of BMP in the associated site or subdivision plan.

When up-to-date inspection and maintenance records are not on file with the municipality and cannot be produced by the property owner, or a BMP is found through inspection to be inadequately maintained, mechanisms to enforce compliance with the conditions of the ECA or maintenance agreement must be in place going forward.

Approaches to Assigning Responsibilities

A critical policy decision facing municipalities regarding inspection and maintenance of stormwater infrastructure is who will be responsible, and for what types of tasks because the decision affects how the program will be designed. In general, there are three (3) approaches a community can use to implement a stormwater infrastructure inspection and maintenance program:

Example of a residential rain garden in Victoria B.C. Eligible for a rebate or ongoing credit under the municipality's "Rainwater Rewards Program" (Photo Source: City of Victoria, 2022).

1. Property Owner Approach: Property owners are responsible for performing all inspection, maintenance and repair/rehabilitation for BMPs on their properties and associated record keeping. The municipality provides inspection and maintenance plan templates, property owner outreach education resources and inspects, maintains and repairs BMPs on their land and within infrastructure rights-of-way. See this approach currently being considered by example CVC by utilizing Ontario's Drainage Act in future SWM plans with municipalities located within their watershed (CVC, 2021).
   
2. Public Approach: Municipality is responsible for performing or tracking inspection, maintenance and repair/rehabilitation of all BMPs that qualify for inclusion in their stormwater infrastructure program, whether located on public or private land (e.g., could include those implemented as part of a stormwater utility fee credit program or CSO abatement plan). See this approach currently being implemented in Mississauga under their Stormwater Charge which included a Stormwater Credit program for ICI and MUR properties within their jurisdiction. This charge program lists eligible LID BMPs to be considered for for meeting the stormwater credit requirements for peak flow reduction, runoff volume reduction and/or quality control (City of Mississauga, 2022)
   
3. Hybrid Approach: A hybrid approach consisting of both public and private entities responsible for various inspection, maintenance and repair tasks. An example of this approach currently being used is in Victoria, B.C. through their Rainwater rewards Program, which helps offset the cost for private property owners to implement one of their recognized LID BMPs. If homeowners are already managing rainwater on their properties they are eligible for further discounts (City of Victoria, 2022.)

The 3 Approaches to Assigning Responsibilities for BMP Management & Repair

Typical Program Characteristics	Strengths / Weaknesses
Property Owner Approach
Property owner responsible for all inspection and maintenance tasks Property owner responsible for maintaining an inventory of all BMPs they own and record keeping related to inspection, maintenance and repair, including results from periodic inspections to verify performance Municipality responsible for educating property owners about the BMP and inspection and maintenance needs Municipality responsible for legal tools to require/enforce maintenance for regulated BMPs on private property	Strengths: Least costly approach for municipalities Weaknesses: Highest potential for non-compliance
Public Approach
Municipality responsible for inspection and maintenance tasks for all regulated BMPs and any others that qualify for inclusion in their program (e.g., part of a stormwater utility fee credit program or CSO abatement plan) BMPs required to meet regulatory requirements should only be located on public property or in rights-of-way Municipality responsible for maintaining an inventory of all BMPs that qualify for inclusion in their program and record keeping related to inspection, maintenance and repair, including results from periodic inspections to verify maintenance and performance	Strengths: Municipality has the most control over maintenance practices and schedules Compliance enforcement issues are minimized Weaknesses: Most costly approach for municipalities
Hybrid Approach
Municipality inspects and maintains BMPs on public land, and within rights-of-way or easements on private property Property owner responsible for performing some inspection and maintenance tasks and record keeping Municipality responsible for an inventory of all BMPs that qualify for inclusion in their program, and periodic inspections to verify maintenance and performance Municipality responsible for educating property owner about the BMP and inspection and maintenance needs Municipality responsible for legal tools to require/enforce maintenance of regulated BMPs on private property	Strengths: Maximum flexibility Useful during transition from property owner to public approaches as programs mature Weaknesses: Potential for noncompliance if roles & responsibilities are not made clear to all parties at the beginning and at regular intervals throughout the lifetime of the program

Best management practice. State of the art methods or techniques used to manage the quantity and improve the quality of wet weather flow. BMPs include: source, conveyance and end-of-pipe controls.

Watercourses and Lake Ontario, to which Stormwater and Combined Sewer Overflows discharge.

Soil, sand and minerals washed from land into water, usually after rain. They pile up in reservoirs, rivers and harbors, destroying fish-nesting areas and holes of water animals and cloud the water so that needed sunlight might not reach aquatic plans. Careless farming, mining and building activities will expose sediment materials, allowing them to be washed off the land after rainfalls.

Box like underground concrete structure with openings in curb and gutter designed to collect runoff from streets and pavement.

Deposition of material of varying size, both mineral and organic away from its site of origin by the action of water, wind, gravity or ice.

Settling-out or deposition of particulate matter suspended in runoff.

Stormwater Management

A lot level bioretention cell designed to receive and detain, infiltrate and filter runoff, typically used for discharge from downspouts.

Credit Valley Conservation

A discharge to the environment from a combined Sewer system that occurs because of a precipitation event when the capacity of the interceptor sewer or treatment plant is exceeded. It consists of a mixture of sanitary wastewater and Stormwater runoff.

The portion of water precipitated onto a catchment area, which then flows as surface discharge from the catchment area past a specified point.

Water from rain, snow melt, or irrigation that flows over the land surface.

Land owned by private individuals or companies.

Low Impact Development. A stormwater management strategy that seeks to mitigate the impacts of increased urban runoff and stormwater pollution by managing it as close to its source as possible. It comprises a set of site design approaches and small scale stormwater management practices that promote the use of natural systems for infiltration and evapotranspiration, and rainwater harvesting.

Land owned by the City Toronto or any other level of government or public agency (such as Toronto and Region Conservation Authority, Toronto Transit Commission, school boards).

A shallow excavated surface depression containing prepared filter media, mulch, and planted with selected vegetation.