Guidelines for Preparing an Operations and Maintenance Plan for Post-Construction Controls

Overview

Boulder County requires that an Operations and Maintenance (O&M) Site Plan (Plan) be submitted for all local projects including a permanent post construction control measure. The Plan shall consist of a single sheet, 22-inches by 34-inches, that includes all the necessary information for long-term maintenance of the site, and shall generally conform to the guidelines that follow. Graphical elements included on the sheet are to reflect as-built record drawing information associated with the completed project.

Contents of Maintenance Site Plan

The following outline shall be used to guide the development of the Plan. Some items may not apply to all projects. Any unique features may warrant inclusion of additional information if pertinent to the anticipated maintenance of the site.

Section 1 – Project Information (can be listed in drawing title)

• General Information
  • Property Owner – contact number
  • Design Engineer – contact number
  • Project Completion Date
  • County Approval Block
• Hydraulic Information
  • Flow Rates – All applicable flow rates should be listed (e.g., base flow, design flow, any storm flows that were evaluated, etc.). Detention facilities should include inflow and outflow rates
  • Facility Description – Include additional design information for the facility, including volumes, water surface elevations, and surface types for forebays and micropools.
  • Outlet Type
  • WQCV Drain Time
• Miscellaneous Information
  • Project Survey Information
    • Include survey control information and at least one on-site “Maintenance Control Point” established during construction for use during maintenance activities.
  • Seed Mix
  • Mow Area – Include area acres and description of mow limits
  • Long-Term Monitoring Requirements
    • If applicable, list monitoring requirements such as 404 permit reports or any other required monitoring.

Section 2 – Project Notes

• General Facility Description
  • Include function, flow source, flow pattern through project, any special features, and any additional information that may be helpful in understanding the basic workings of the facility.
• Maintenance Notes
  • Maintenance Frequency
  • Equipment and Special Tools Required
  • Power Source (if applicable)
• Maintenance Procedure
  • Dewatering
  • Sediment Removal
  • Debris Removal
  • Site Inspection
    • List all general features and equipment that should be inspected to ascertain additional maintenance needs.
  • Materials Testing
    • List any contaminant testing requirements for sediment removed from the pond.
  • Post-Maintenance Considerations
    • Any additional maintenance-related tasks should be listed here. These may include restoring flow patterns, replacing or removing stoplogs, or additional cleanup requirements.

Section 3 – Site Plan

• Vicinity Map
• Plan View – All major features of the facility should be labeled, including:
  • Trickle Channel
  • Forebay, longest reach distance required from access road
  • Micropool, longest reach distance required from access road
  • Entrance Structure
  • Outlet Structure
• Special Maintenance-Related Information Should Be Verified
  • Maintenance control point location and elevation
  • Maintenance entrance/access road/gates/turnarounds
    • List applicable information such as road material, width, maximum grade, etc.
  • Power source
  • Weight-restricted areas
  • Wetland or natural areas to avoid
• Hydraulic Profile
  • Major features
  • Permanent pool elevations
  • Other applicable water surface elevations
  • Flow direction
  • Shading identifying forebay and micropool sediment removal zones

Section 4 – Details (relevant to the BMP on site – rain garden/PLD, EDB, sand filter basin, etc.)

• Trickle channel section
• Maintenance road/access
• Inlet strucutre(s)
• Forebay release structure
• Outlet structure

Submittal Requirements

The Engineer shall submit one 22-inch wide by 34-inch long Maintenance Site Plan with the project’s post-construction submittal package that is required for applicable development sites that disturb one-acre or greater within the County’s urbanized area. Any comments shall be addressed by the Engineer until approval has been granted by the County. Once approval has been granted, the final submittal shall include:

• One electronic PDF of a 22-inch by 34-inch maintenance site plan (stamped by a Professional Engineer)
• CAD files

View an example of the Maintenance Site Plan to be submitted.