3.2 Water Quantity

  1. Drainage is conveyed through the subwatershed through culverts and small channels to wetlands, most of which are ditched or drain to Painter Creek.  The Upper Watershed Stream Assessment identified 11 locations on the Creek with erosion or bank failure, most of them concentrated in about 1400 linear feet of that study’s Reach 1.   The HHPLS included a study of scour potential in the creek, and concluded that some reaches were at moderate to high risk for erosion. 
  2. The HHPLS identified three locations that are predicted to overtop during the 100 year event: two driveways and a location on Ingerson Road.   More detail is available in the HHPLS.  Local plans should identify these observed or potential locations and assess whether the risk of occasional flooding is acceptable or should be addressed.
  3. The HHPLS identified two locations requiring special attention: the outlet of Katrina Lake and the outlet of the Highway 26 marsh.  Excessive cattail growth can limit the operation of the lake outlet.  At the outlet of the Highway 26 marsh, a channel has formed around the outlet bypassing the control structure.
  4. Development, redevelopment, and reconstruction in the subwatershed may increase the volume of stormwater runoff, increasing nutrient and TSS loads conveyed downstream.
  5. The HHPLS identified several locations where for both existing and future conditions higher velocities than desired may result in erosion at outlets or culverts.   These include three crossings of CR 6, and a crossing of Ingerson Road west of Painter Marsh.  Erosion control or energy dissipation measures may be required in those locations.