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2012 SWMMWW Reference:
• Volume I, Chapter 2 – Minimum Requirements for New and Redevelopment, pages 2-1 to 2-2

2. WHEN DO MINIMUM REQUIREMENTS #1 THROUGH #5 APPLY?

Projects are evaluated based on project type, size, and other thresholds to determine which Minimum Requirements apply to the project. If your project is:
• Creating or replacing between 2,000 and 5,000 square feet of hard surfaces (such as building an addition, adding a new driveway)
• OR disturbing between 7,000 square feet and 33,000 square feet (¾ acre)

Then most likely, Minimum Requirements #1 through #5 will apply to your project. Rain Gardens are not appropriate for larger projects that are
required to meet all Minimum Requirements #1 through #9.

Examples of projects where Minimum Requirements #1 through #5 apply:
Hard surfaces that trigger Minimum Requirements #1 through #5 include any impervious surface, permeable pavement or vegetated roofs. Disturbed
areas include when your project converts vegetation to lawn. Examples of projects that would trigger Minimum Requirements #1 through #5 include:
• A new 2,000 square foot roof.
• A 1,000 square foot asphalt driveway that is replaced (not just overlaid or resealed). This example assumes that existing asphalt is removed to the
underlying gravel and 1,000 square feet of asphalt is added to widen the driveway and increase parking.
• A new 2,000 square foot gravel driveway.

• 7,000 square feet lot is cleared and replaced with a 1,000 square foot building, 500 square feet of asphalt and 5,500 square feet of lawn.

2012 SWMMWW References:
• Volume I, Chapter 2, Section 2.4—Applicability of the Minimum Requirements, pages 2-9 to 2-15
• Volume I, Chapter 2, Section 2.5—Minimum Requirements, Minimum Requirements #1 through #5, pages 2-16 to 2-32

3. HOW DO RAIN GARDENS FIT INTO MINIMUM REQUIREMENT #5?
In the 2012 SWMMWW, rain gardens are considered as an On-site Stormwater Management Best Management Practice (BMP). On-site Stormwater
Management BMPs are a synonym for Low Impact Development (LID) BMPs. It is important to note that rain gardens are not considered as a
“Stormwater Treatment and Flow Control BMP/Facility” (used to satisfy Minimum Requirements #6 and #7).

Minimum Requirement #5: On-site Stormwater Management, requires the use of On-site Stormwater Management Best Management Practices
(BMPs) to infiltrate, disperse, and retain stormwater runoff on-site to the extent feasible without causing flooding or erosion impacts. This requirement