A Stormwater Design Manual Toolbox

What Do You Need in a Local Stormwater Manual?
About the Manual Builder

Browse by contents: Choose One Local Review Process Sizing Criteria Performance Criteria Selection Matrices Stormwater Credits Construction Specifications Design Examples Construction & Maintenance Checklists References STP Maintenance
See information on a specific STP Design: Choose One Filtering Systems Infiltration Open Channels Ponds Wetlands

What Do You Need In a Local Stormwater Manual?

The stormwater manual guides local engineers so that they can comply with the stormwater requirements prescribed in the local stormwater ordinance. A good manual contains specific guidance on how to select, size, design, construct, and maintain practices at each development site. A typical manual will contain the following elements:

Basic Stormwater Requirements
The manual will typically detail the legal requirements as set forth in the Stormwater Ordinance.

• Procedures for Reviewing Stormwater Plans
  In this section, the manual outlines the process a community should go through to review the stormwater plan.
• Basic Sizing Criteria
  The manual needs to identify minimum sizing criteria for practices to meet groundwater recharge, water quality, channel protection, and flood control requirements.
• List of Acceptable Practices
  The manual should include a list of practices that can meet water quality requirements. An engineer can choose from this menu of practices to treat stormwater runoff from a new development.
• Performance Criteria
  The performance criteria provide required minimum elements and guidance to ensure that practices are designed and maintained to ensure practice longevity and performance.
• Guidance on STP Selection
  This section presents criteria to guide the design engineer to select the best practice for the site, based on characteristics such as soil type, site slope, and the local watershed conditions.
• Stormwater Credits
  Stormwater credits are reductions in stormwater volume requirements given in exchange for incorporating site design techniques that minimize the need for STPs on the site. Many manuals do not incorporate credits, because they can increase the burden of review on local governments substantially.
• Design Examples
  Design examples step the engineer through designs for a representative group of STP design variations. They should illustrate how to select, size, and locate the practice on the site.
• Construction Specifications
  Construction specifications detail specific materials and construction standards that ensure that the practice will function as designed.
• Checklists for Construction Inspection
  These checklists outline what minimum elements are needed for each practice group during construction.

About the Manual Builder

The Manual Builder provides a toolbox for developing a stormwater treatment practice (STP) design manual. It includes STP design and construction criteria and provides schematics and graphics for each practice. It also provides information about maintenance requirements and the typical local review process for STP design and construction. Each manual needs to be customized to meet the needs of the community where it is being applied. As a result, the manual builder does not prescribe one specific set of criteria, but instead presents a series of options for stormwater managers to choose from. Key decision points for the stormwater manager are identified with this symbol: