Bayou Lafourche

Introduction ...................................................................................................... 3
Upper Bayou Lafourche Watershed:............................................................... 4
History ............................................................................................................... 6
Bayou Lafourche Water Quality ..................................................................... 8
Designated Uses....................................................................................................................................... 8
Water Quality Criteria ........................................................................................................................... 9
Ambient Sampling ................................................................................................................................ 10
Impairments .......................................................................................................................................... 11
Total Maximum Daily Loads (TMDLs) ........................................................ 12
TMDL for Dissolved Oxygen and Nutrients ...................................................................................... 12
TMDL for Fecal Coliforms .................................................................................................................. 16
Sources of Impairment ................................................................................... 20
Hydromodification................................................................................................................................ 20
Agriculture ............................................................................................................................................ 25
Urban Runoff ........................................................................................................................................ 27
Onsite Disposal Systems (Septic Tanks) ............................................................................................. 29
Grazing .................................................................................................................................................. 31
Nonpoint Source Management Measures ..................................................... 32
Hydromodification Management Measures ....................................................................................... 33
Agriculture Management Measures ................................................................................................... 36
Urban Runoff Management Measures ............................................................................................... 40
Onsite Disposal System Management Measures ................................................................................ 49
Grazing Management Measures ......................................................................................................... 51
Implementing Change .................................................................................... 53
Public Participation .............................................................................................................................. 54
Regulatory Authority ........................................................................................................................... 54
DEQ Actions .......................................................................................................................................... 55
Actions by Other Agencies ................................................................................................................... 57
Tracking and Evaluation ............................................................................... 60
Implementation Timeline ............................................................................... 61
References ....................................................................................................... 62