For Stormwater Professionals

The Keep it Clean partners have adopted ordinances that control all construction and development activity that disturbs one or more acres of land, as well as activity that disturbs less than 1 acre of land, but is part of a larger common plan of development.

The owner and/or operator of the construction site will be responsible for complying with these requirements and plays a key role in protecting our water quality. These requirements include temporary erosion and sediment control practices during construction and the installation of permanent stormwater quality facilities to ensure long-term protection of the water quality for runoff from the developed site. Fines up to $1,000 per day may be imposed for ordinance violations.

In general, construction and development contractors are responsible for:

During Design Review— Owner/operator must develop the following:

1. 1. Stormwater Management Plan (SWMP), including erosion and sediment control practices and proposed permanent stormwater quality controls or Best Management Practices (BMPs). Guidelines for preparing a SWMP can be found at CDPHE’s website. Temporary and permanent stormwater quality controls, or BMPs, are to be designed according to the Urban Drainage and Flood Control District’s Urban Storm Drainage Criteria Manual –Volume 3, or other methods approved by the community.
   2. Owner/operator is responsible for the following: executing a maintenance agreement with the municipality to ensure future inspection, maintenance, repairs, and proper functioning of the permanent BMPs.

During Pre-Construction Meeting— Owner/operator must provide:

1. 1. A copy of the application submittal for coverage under the State’s General Permit of Construction Activities.
   2. Documentation of an erosion and sediment control administrator for personnel responsible for supervising the installation and maintenance of sediment and erosion control practices.

During Construction— Owner/operator is responsible for the following:

1. 1. Maintain a copy of the SWMP onsite at all times. The approved SWMP must be maintained and made available upon request.
   2. Install and maintain erosion and sediment control BMPs as specified in the SWMP. Sediment, debris or other pollutants from construction operations must be managed to prevent flow to the storm drainage system.
   3. Maintain inspection and maintenance records of BMPs onsite with the SWMP.
   4. The installation and maintenance of BMPs shall be supervised by personnel certified in erosion and sediment control.

After Construction— Owner/operator is responsible for the following:

1. 1. Implement ongoing inspection, maintenance, and repairs of permanent BMPs according to the maintenance agreement with the municipality.
   2. Submit written documentation that permanent BMPs were constructed in accordance with approved plans submitted in the design review phase.

General Requirements for all Construction Activities (regardless of size) –
Owner/operator is responsible for the following:

1. 1. Manage construction activities to prevent the illegal discharge of sediments or other pollutants to the storm drainage system.
   2. Receive a permit from CDPHE to discharge any non-stormwater discharge to the storm drainage system. These discharges may include those covered under the State’s CDPS permit system, such as construction dewatering.

For more specifics about these requirements contact the Keep it Clean Partner responsible for the jurisdiction in which your project is located.

Training

• Colorado Stormwater Center at Colorado State University

Resources

• The International Stormwater Best Management Practices Database

Research

• International Stormwater BMP Database

Colorado Stormwater Resources

• Colorado Water Quality Control Division
• Urban Drainage and Flood Control District
• Colorado Association of Stormwater and Floodplain Managers
• Colorado Stormwater Council
• Nonpoint Source Colorado

What is Low Impact Development (LID)?

The literature is full of terms such as “Smart Growth”, “Low Impact Development”, and “Sustainable Development.” All of these terms refer to stormwater management practices that promote the reduction of runoff volume from urban areas.

The goal of LID is to allow for development of a site while maintaining as much of its natural hydrology as possible, such as infiltration, frequency and volume of discharges, and groundwater recharge.

In the LID approach, stormwater is managed in small, source control landscape features rather than in large, end-of-pipe pond structures located at the downstream extent of drainage areas. However, ponds may be required in addition to LID to create a “treatment train” effect. Through LID, hydrologic functions such as infiltration, peak and volume of discharges, and ground water recharge can be maintained with the use of reduced impervious surfaces, functional grading, open channel sections, disconnection and utilization of runoff, and the use of bioretention/filtration landscape areas.

With the LID approach, receiving waters experience little change in the volume, frequency, or quality of runoff or in the base flows fed by groundwater.

Design Before Construction

All the KICP communities reference Urban Drainage and Flood Control’s Volume 3 for SCM design. The Urban Drainage Flood Control District Volume 3 Outlines the four-step SCM planning process:

1. Implementing stormwater runoff reduction practices.
2. Providing treatment of the Water Quality Capture Volume.
3. Implementing streambank and channel stabilization techniques for any drainage ways within or adjacent to a project site.
4. Providing additional treatment for pollution hot spots.

Developers, please consider LID when submitting your plans

Stormwater quality needs to be addressed early in the design process. It is recommended that discussions regarding proposed LID elements occur early in each project between the developer’s planner, engineer, and municipal staff. Here are some ideas to consider as you think about ways to incorporate LID into your plans:

• Implement source controls to prevent and minimize the discharge of pollutants and incorporate stormwater treatment controls to remove pollutants from runoff.
• Minimize directly connected impervious areas and maximize permeability at a project site.
• Select treatment areas that promote greater infiltration and use drainage as a design element.
• Reduce runoff rates and volumes to more closely match natural conditions and look for opportunities to assist with flood control.
• Protect sensitive areas from encroachment with design elements.

The focus of LID design is to manage the stormwater as close as possible to its source. This means managing stormwater on each individual lot rather than conveying the runoff to a larger regional pond. Retrofitting sites to improve water quality is also essential to the health of our streams.

All the KICP communities require that owners inspect and maintain their SCMs to ensure that they are working properly. Inspections and maintenance are necessary to ensure the SCM functions as designed and has a positive impact on local stream quality.

Inspection and maintenance plans detailing inspections, maintenance, frequency, and estimated costs are highly recommended, and in some cases it is required.

Gather your resources

• Review the Colorado Stormwater Center’s Permanent Water Quality BMP Inspection and Maintenance Field Guide or this Owner’s Guide Stormwater Control Measure Maintenance by the City of Boulder.
• Get a copy of your communities’ site plan and as-built drawings.
• Locate your SCM(s).
• Contact a representative from your community to help determine the inspection and maintenance needs of your BMP to ensure it continues to function as designed.
• Write up an inspection and maintenance plan with the corresponding budget.
• Enter into a contract or schedule internally for inspection and maintenance.
• Save your inspection and maintenance records. Your community may request to review them or you may be required to submit them annually.