Low Impact Development Manual for Michigan - OSEH - University ...

BMP Fact Sheet
Protect Natural Flow
Pathways
A main component of LID is to identify, protect, and use natural drainage
features, such as swales, depressions, and watercourses to help protect water
quality. Designers can use natural drainage features to reduce or eliminate
the need for structural drainage systems.
Natural flow pathway in residential development
Source: Brandywine Conservancy, Environmental Management Center, 1998
Applications Stormwater Quantity Functions
Residential Yes Volume Low/Med
Commercial Yes
Groundwater
Recharge
Variations
• Check dams to slow velocity
• Earthen berms for additional
storage
• Additional native vegetation
for increased infiltration
Key Design
Features
• Identifies and maps natural
drainage features (e.g., swales,
channels, ephemeral streams,
depressions, etc.)
• Uses natural drainage features
to guide site design
• Distributes non-erosive
surface flow to natural
drainage features
• Keeps non-erosive channel
flow within drainage pathways
• Uses native vegetative buffers
Benefits
• Maximizes natural hydrological
functions
• Reduces structural management
practices
• Reduces management costs
Limitations
• Minimal water quality benefits
LID Manual for Michigan – Chapter 6 Page 83
Low
Ultra Urban No Peak Rate Med/High
Industrial Yes Stormwater Quality Functions
Retrofit Yes TSS Low/Med
Highway/Road Yes TP Low/Med
Recreational Yes
NO3 Temperature
Low
Low
Additional Considerations
Cost Low
Maintenance Low/Med
Winter Performance Low/Med