Susceptibility of wetland types to degradation by stormwater input
Link to this table
Susceptible |
Non-Susceptible |
Highly Susceptible Wetland Types 1 |
Moderately Susceptible Wetland Types 2 |
Slightly Susceptible Wetland Types 3 |
Least Susceptible Wetland Types 4 |
- Sedge Meadows
- Open Bogs
- Coniferous Bogs
- Calcareous Fens
- Low Prairies
- Coniferous Swamps
- Lowland Hardwood Swamps
- Seasonally Flooded Basins
|
- Shrub-carrsa
- Alder Thicketsb
- Fresh (Wet) Meadowsc,e
- Shallow Marshesd,e
- Deep Marshesd,e
|
- Floodplain Forestsa
- Fresh (Wet) Meadowsb
- Shallow Marshesc
- Deep Marshesc
|
- Gravel Pits
- Cultivated Hydric Soils
- Dredged Material / Fill Material Disposal Sites
|
- 1. Special consideration must be given to avoid altering these wetland types. Inundation must be avoided. Water chemistry changes due to alteration by stormwater impacts can also cause adverse impacts. Note: All scientific and natural areas and pristine wetlands should be considered in this category regardless of wetland type.
- 2a, 2b, 2c. Can tolerate inundation from 6 inches to 12 inches for short periods of time. May be completely dry in drought or late summer conditions.
- 2d. Can tolerate +12” inundation, but adversely impacted by sediment and/or nutrient loading and pro- longed high water levels.
- 2e. Some exceptions.
- 3a. Can tolerate annual inundation of 1 to 6 feet or more, possibly more than once/year.
- 3b. Fresh meadows which are dominated by reed-canary grass.
- 3c. Shallow marshes dominated by reed-canary grass, cattail, giant reed or purple loosestrife.
- 4. These wetlands are usually so degraded that input of urban stormwater may not have adverse impacts.
Notes:
There will always be exceptions to the general categories listed above. Use best professional judgment. Pristine wetlands are those that show little disturbance from human activity.