Climate Resilience Design and Engineering


Developing a Risk-based Plan

Maintenance based on level of risk and consequence of failure is the optimal solution and best practice for asset management. Risk-based maintenance incorporates some key issues not dealt with by other maintenance programs. It recognizes that:

  1. Certain equipment may be more important for facility safety and processes
  2. Equipment design and operations differ
  3. Different equipment will have a higher probability to undergo failures from different degradation mechanisms than others

Risk-based maintenance programs recognize that a facility does not have unlimited financial and personnel resources, and that the use of both must be prioritized and optimized. Follow the steps below to develop a Risk-based plan.

Build an Asset Inventory

Your risk-based plan must include a standard for defining, identifying, and storing asset data to keep those data consistent and correctly labeled to best meet the utility’s needs. This is called an "asset inventory." Construction of an asset inventory allows an owner to prioritize the assets, calculate risk, and identify lifecycle costs. (Note, asset management and computerized maintenance management system (CMMS) software is ideal for preparing an asset inventory.)

Construct the Inventory

To build the inventory, you should identify key attributes of each asset:

  • Type and Function: Municipalities should consider hard assets (i.e., storm drain system pipes and related control components), human-based resources, and natural assets
  • Location: Geospatial location coordinates are a prerequisite best practice asset management
  • Installation/Repair Information: Attributes such as installation date, repair dates, replacement dates, maintenance frequency, staff-hours, equipment, and materials

Prioritize Assets and Calculate Risk

To prioritize assets, assign a "risk score." Consider each asset’s:

  • Condition: An asset’s condition is indicative of its likelihood of failure and how much attention it may need to continue to deliver at the desired level. This can be guided by a pre-developed rating system.
  • Remaining Useful Life: Determining the remaining useful life of an asset is critical to ensuring that an asset continues to meet its performance objectives before unforeseen failure
  • Probability of Failure: A probability of failure score can be based solely on an asset’s condition or calculated as a composite score incorporating more information, such as age, performance, and maintenance history
  • Consequence of Failure: This indicates the potential for a disruption in service and the magnitude of its effect, considering the social, environmental, and financial consequences of failure, including health and safety

Undertake Lifecycle Costing

Lifecycle costing is a tool that uses information on owned assets, the function of those assets, and an assessment of which ones are critical to the sustained operation to help municipalities make informed decisions about operations and maintenance (O&M) and asset replacement. Although the lifecycle costing process is the most complex part of asset management, it allows the best use of limited dollars.

Develop Performance Metrics

Having a completed asset inventory allows a municipality or utility to establish performance metrics and indicators for each asset, in the context of entire system, to meet system-wide Level of Service (LOS) standards. It is likely that some assets play a more critical role in meeting system-wide LOS standards than others. A utility can take the following steps to determine the key assets and performance indicators that should be monitored:

  1. Identify those assets that affect performance of the stormwater system (environmental, cost, and/or community/safety)
  2. Identify the metrics associated with these assets that are indicative of asset performance
  3. Develop thresholds for these metrics that trigger actions beyond the prescribed maintenance actions for that asset

For gray infrastructure, conveyance pipes and ditches, vaults, ponds, tide gates, and mechanical systems can be monitored in terms of (a) functionality or (b) physical condition to determine a performance indicator.

For green infrastructure, vegetation/soil condition, sedimentation/debris accumulation, and ponding/infiltration (functionality) can be monitored to serve as performance indicators.

Examples of performance metrics may include:

  • Measuring annual performance goals for system inspection, cleaning, maintenance, rehabilitation, and capital improvement
  • Correlating education and enforcement measures with expected reductions in services calls, floods, and customer complaints
  • Establishing maximum emergency response time to emergency calls and tracking customer complaints and claims for private property restoration (e.g., customer complaints will be responded to within X hours, Monday through Friday)
  • Performing cost-benefit analyses of key completed activities, taking into account expected versus actual outcome and budgeted versus actual cost

Create an Asset Management Plan

Creating a stormwater Asset Management Plan (AMP) is the key step towards integrating your asset inventory, condition assessment, financial analysis, and other information into an asset management framework for your stormwater facilities and operations (as outlined below). The current best management practice for ensuring asset planning is through the development and implementation of an AMP.

Asset management planning consists of developing a plan to reduce costs of stormwater management while increasing the efficiency and the reliability of assets. An AMP incorporates asset inventories, operation and maintenance tasks, and long-range financial planning to ensure that annual revenue reserves and reinvestment are sufficient to facilitate long-term viability of the system.

The five major, generally recognized components of an asset management plan include the following items:

Getting Started

An AMP does not have to be complicated or lengthy to be useful. It can be a very simple document written in such a way that everyone can understand it. There are several actions you can take to get started on an AMP:

  1. Establish a mission statement
  2. Inventory your sources of data regarding facilities and condition
  3. Identify needed financial information: current funding, cash flow, future needs

A stormwater AMP should provide:

  • Mission statement and service goals for your stormwater management operations;
  • History and present state of your stormwater system: indicate when major system components/assets began operation, how the stormwater system has evolved, describe how runoff is generated, the miles of pipe, the number of catch basins, inlets, and discharge and other structures, and the condition and maintenance processes for important assets;
  • Future outlook for stormwater services: how does private construction add drainage system elements to the stormwater system; how does the local jurisdiction require and review drainage system installation; does the town own and operate stormwater facilities on public land (aside from streets); what future conditions will apply to the stormwater system, such as implementation of green stormwater infrastructure, and changes in development requirements and patterns; and if the type and extent of stormwater services are expected to evolve or change in the future;
  • How to fund the desired level of stormwater operations and maintenance, and capital expansion (if needed)

Value and Benefits of a Stormwater AMP

  • Helps to create an inventory of key stormwater system assets and their condition
  • Identifies high priority asset needs that are critical to stormwater system performance
  • Improves response to emergency situations
  • Provides information to aid communications inside and outside the stormwater operation
  • Clarifies the costs of existing operation and maintenance, and future O&M
  • Supports planning for future capital and operating expenditures to meet service objectives
  • Helps with decisions on the best way to spend limited funds for stormwater service
  • Can help fulfill funding requirements or activities that provide additional points or a higher ranking on a funding application
  • Helps characterize and respond to the risks of stormwater system failures, especially characterizing flood and quality of life risks

This page was informed by these resources.