section 4 - existing conditions and needs - Martin County, Florida

geographical limits of the CRA. Salerno Creek and Manatee Creek have been studied;
the remaining five have not. Approximately 56% of the CRA is in drainage basins which
have not been studied. Since the CRA is downstream of the basins, caution should be
exercised when proposing improvements impacting the upstream portion of the basins.
Additional studies are warranted to ensure downstream improvements do not adversely
impact existing and future upstream development.
4.8 LEVEL OF SERVICE AND WATER QUALITY RECOMMENDATIONS
The Salerno Creek and Manatee Creek water quality retrofit projects have addressed
44% of the water quality needs of the CRA drainage system. The improvements have
established permissible discharge rates in the CRA. Future projects should use the two
projects as guidelines, where applicable, to prevent complications. The permissible
discharge into Manatee Pocket from Manatee Creek is 0.47 cfs/ac. The permissible
discharge into Manatee Pocket from Salerno Creek is 0.68 cfs/ac. The studies
adequately provided for hydraulic capacity to handle LOS storm events. However, the
system has hydraulic problems when hydraulic connectivity is considered.
Recommendations have been developed to solve the system deficiencies for LOS, water
quality, and nuisance concerns. The recommendations have been compared and
presented in order of their importance and ease of solution. Top ranked
recommendations should be considered as priority projects.
Solutions to system problems and deficiencies are provided below. The
recommendations will address hydraulic and water quality concerns in the CRA district.
The following recommendations are prioritized based on their needs and should be
considered as the necessary projects to meet LOS requirements to the fullest extent
possible for Port Salerno.
4.8.1 New Monrovia
Open space is available throughout New Monrovia for the construction of stormwater
treatment areas (STA’s) to provide water quality treatment. Specifically, the area around
SE 48 th Avenue, where there have been reported flooding issues would be retrofitted
with an STA to provide water quality treatment and storm runoff attenuation. The
southern part of the CRA near the Charles Street Ditch may discharge into the ditch,
after receiving water quality treatment and discharge through the Manatee Creek
Stormwater Quality Retrofit improvements.
4.8.2 Rocky Point
Rocky Point has less vacant land available than other areas in the CRA; therefore,
STA’s may not be feasible. The area possesses highly permeable soils with existing
elevations, which would enable the use of exfiltration trench for water quality treatment.
Low intersections and streets which flood would be retrofitted with drainage structures
and exfiltration trench to reduce the frequency of flooding. Finding positive outfalls for
treated stormwater runoff may be difficult where there are existing bulkheads at Manatee
Pocket.
MARTIN COUNTY STORMWATER/UTILITY CRA MASTER PLAN – PORT SALERNO CRA SECTION 4-8
EXISTING CONDITIONS AND NEEDS (07/03/06)