The intent of this credit is to reduce or limit the stormwater run-off rate and quantity to minimize impact on natural hydrology. Many jurisdictions require stormwater management that fulfill the requirements of this credit.

Requirements for Certification:

Option 1 - Existing Imperviousness is less than or equal to 50%. Prevent the post-development peak discharge rate and quantity from exceeding the pre-development peak discharge rate and quantity OR Protect receiving stream channels from excessive erosion through the use of a stream channel protection strategy and quantity control strategies.

Option 2 - Existing Imperviousness is greater than 50%. Decrease the volume of pre-development stormwater runoff volume by 25%.

Successful Strategies:

• Retention Ponds
• Detention Ponds
• Pervious paving materials
• Bioswales
• Green Roofs and/or Stormwater reuse

Helpful Hints:

1. When doing the calculations for this credit do not overlook run-off from the roof.
2. The stormwater management for this credit can be costly depending on the design.
3. Underground water storage has become more prevalent, but can be costly.
4. Many of the strategies used for this credit will also contribute to SSc6.2.
5. LEED uses a two-year storm event as the basis for the LEED SSc6.1 calculation.

Historical Data (updated June 2006):

• 33% of all California LEED Certified projects achieved this credit for LEED v2.1

Additional EDR Resources

Case Studies: Thinking outside the Box

Design Briefs: Design For Your Climate

E-News for Designers: e-News #7: Design Communities with Built-in Energy Efficiency.