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

4.1 BACKGROUND
SECTION 4 - EXISTING CONDITIONS AND NEEDS
Section 2 - Resources and Data lists the existing information and data collected,
compiled and analyzed as part of the review of the existing conditions of the stormwater,
water and wastewater systems that serve the Port Salerno CRA. In Section 3 -
Governing Rules and Regulations, the required Level of Service (LOS) for stormwater
water quality and storm attenuation is defined as well as the required LOS for water and
wastewater facilities. Based on this information, an analysis has been performed and
exhibits have been created to show existing areas within the Port Salerno CRA that are
currently deficient in providing the required LOS for stormwater, water and wastewater
facilities.
4.2 EXISTING STORMWATER FACILITIES
A series of north-south ridges and depressions form the drainage patterns, in this area of
Martin County, as described by the United States Geologic Survey (USGS) topographic
maps, County records, and geologic reports procured from the South Florida Water
Management District. Figure 11, “Existing Contours” illustrates the existing
topographic features of the Port Salerno CRA (one foot contours, as provided by Martin
County). The Port Salerno CRA is located adjacent to, and east of the Atlantic Coastal
Ridge (see Figure 1). Figure 10, “Soils Map” provides the typical characteristics of
the soil in this area.
The Port Salerno CRA is in the Manatee Pocket Basin. Two principal tributaries drain the
CRA; Salerno Creek (FDOT Ditch 4 and FDOT Ditch 5) west of SE Dixie Highway and
Manatee Creek east of SE Dixie highway. Smaller lateral ditches and local roadside
swales and ditches provide drainage for the CRA. The St. Lucie River is the ultimate
receiving body of water for discharge of stormwater in the area. Permitted discharge
rates in this area are in the 0.68 cfs/ac range (in accordance with permits issued by
SFWMD).
Martin County commissioned Creech Engineers, Inc. to study the Salerno Creek Basin
and recommend water quality improvements to retrofit the area. As a result of the study,
a 24 acre stormwater treatment area (STA) was constructed. The STA provides
approximately 53 ac-ft. of stormwater treatment volume for runoff. Captec Engineering,
Inc. completed the Manatee Creek Stormwater Quality Retrofit design in 2005.
Approximately 40% percent of the CRA has been retrofitted with stormwater facilities
providing water quality. Currently, the remaining CRA does not have adequate
stormwater facilities providing the required minimum treatment according to Martin
County Land Development Code or SFWMD water quality requirements.
MARTIN COUNTY STORMWATER/UTILITY CRA MASTER PLAN – PORT SALERNO CRA SECTION 4-1
EXISTING CONDITIONS AND NEEDS (07/03/06)

The existing stormwater infrastructure in the Port Salerno CRA is limited. The lack of
stormwater treatment and adequate conveyance systems is evident in the stormwater
inventory for the area. Figure 12, “Existing Stormwater Facilities” illustrates the
existing stormwater facilities as identified by Martin County in their GIS system. Prior to
1972 (when the County stormwater ordinances were codified) residential subdivisions,
multi-family housing, and commercial property were not required to provide water quality
treatment or flood attenuation for storm runoff when they were constructed.
More recent development must provide drainage facilities in order to comply with the
required stormwater LOS in accordance with Martin County codes and the requirements
of the South Florida Water Management District (SFWMD). Table 4.2-1 and Figure 7,
“South Florida Water Management District Permits” list the developments within and
adjacent to the Port Salerno CRA, having a SFWMD Surface Water or Environmental
Resource permit. For the purpose of conducting an analysis of existing conditions, they
are assumed to meet current LOS.
Table 4.2-1
South Florida Water Management District Permits
Project Name Permit Number
River Pines 43-00141-S
Emerald Lakes Phases 14 & 15 43-00239-S
Park Place 43-392-S-12
Scammell Construction Office 43-00392-S-12
FECR Fiber Optics Regenerating Facility 43-00392-S-16
Castle Development Warehouse 43-00392-S-17
Lot 10, Block D, Gran Park-Phase I 43-00392-S-20
Lot 9, Block D, Gran Park-Phase I 43-00392-S-21
H & L Marine 43-00392-S-22
Gran Park Commerce 43-00392-S-23
Woodridge 43-00549-S
CR A1A/Salerno Road 43-00664-S
Toyota of Stuart 43-00944-P
Manatee Creek Stormwater Quality Retrofit 43-00971-P
Ebbtide Avenue Bridge 43-00979-P
Salerno Village Square 43-01105-P
Port Salerno Post Office 43-01217-P
Manatee Cove Road Culvert Replacement 43-01271-P
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EXISTING CONDITIONS AND NEEDS (07/03/06)

Port Salerno Elementary School 43-01331-P
Murray Cove 43-01375-P
Cove Road Commercial Center Walgreen’s 43-01499-P
Port Salerno Industrial Park 43-01755-P
Salerno Cove/Cove Place 80-00119-S
Grankill Apts. Azimuth St. Port Salerno 82-00033-S
Greenwood Estates 82-00147-S
4.3 EXISTING CONDITIONS – SPECIFIC AREAS
4.3.1 New Monrovia New Monrovia is west of S.E. Dixie Highway, at the south end of the
CRA. New Monrovia was identified in the Port
Salerno Community Redevelopment Plan as a
neighborhood with redevelopment potential. The
area experienced flooding during 1995, 1999, and
2001. The American Red Cross and Martin
County logged complaints received from
residents impacted by the flooding. Captec
Engineering, Inc. studied the problem in the
Manatee Creek Stormwater Quality Retrofit
Report, and modeled storm events approximating
the actual events which caused the flooding.
New Monrovia would be expected to flood again
should a similar event occur, due to the lack of
capacity in existing swales and ditches.
New Monrovia
4.3.2 Rocky Point Rocky Point is east of S.E. Dixie Highway and one of the four residential
areas in the CRA. Rocky Point was built prior to modern stormwater codes and ordinances
requiring water quality treatment. Intersections
are known to flood due to being constructed in
low areas without any drainage outlet (positive
outfall). The Community Redevelopment Plan
listed streets prone to flooding: Broward Street;
Driftwood Avenue; George’s Way; and, S.E.
Mulford Lane. County stormwater inventory
indicates only 2 small swales and pipe in the
area which illustrates the lack of stormwater
facilities available. The soils in the area are
highly permeable; however, when discharge
occurs the flow goes directly into Manatee
Rocky Point
Pocket.
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EXISTING CONDITIONS AND NEEDS (07/03/06)

4.3.3 Port Salerno Platted as Port Salerno in
1912, the subdivision is one of the oldest in
Martin County. The Salerno Creek Water
Quality Retrofit was constructed to improve the
water quality discharging into Manatee Pocket.
Existing isolated roadside swales and ditches
provide drainage to local streets, including S.E.
Salerno Road and the Port Salerno
Elementary School ditch. The County is aware
of recurring flooding at the intersection of S.E.
Salerno Road and Flounder Avenue. In
addition, there is flooding in the upstream
reaches of the elementary school ditch.
Manatee Creek
4.4 EXISTING CONDITIONS – STORMWATER MODEL
Port Salerno
4.3.4 Manatee Creek The main access to the
subdivision is provided by S.E. Primrose Way
at Cove Road. Dead end streets characterize
the layout of the subdivision. Stormwater
treatment areas recommended in the Manatee
Creek Stormwater Quality Retrofit are currently
under construction to provide water quality
treatment to this area of the CRA. Phase I is
under construction, and Phases II and III have
been designed.
In order to confirm reports of existing stormwater deficiencies and to identify additional
areas of concern, stormwater modeling was conducted using the available data for
existing conditions within the Port Salerno CRA. The model used for this existing
conditions study was the Interconnected Channel and Pond Routing Model (ICPR). This
model was selected in order to be consistent with methodology used in the proposed
Stormwater Master Plan modeling included under Section 5.
The Port Salerno CRA was divided into existing drainage basins according to existing
contour maps, basin maps, and stormwater reports. For basins studied and not
modeled, the information was incorporated where applicable. Pervious and impervious
areas within each existing drainage basin were determined using building area
information provided by the Martin County Tax Assessment Office with additional area
MARTIN COUNTY STORMWATER/UTILITY CRA MASTER PLAN – PORT SALERNO CRA SECTION 4-4
EXISTING CONDITIONS AND NEEDS (07/03/06)

calculations based on existing plans and current aerial photographs of the CRA as
provided by Martin County.
Based on soil conditions and depths to water tables as indicated in Figure 10, “Soils
Map” along with the calculated impervious areas, a Curve Number (CN) was determined
for each basin. Stage/storage calculations for the model are based on the existing
contour map. In order to account for the high permeability of the existing soils in the east
Port Salerno area, a stage discharge rating curve was developed for those areas using
the soils data and hydraulic conductivity in the Martin County Soil Survey.
Stormwater models were run (see Appendix - Pre-redevelopment ICPR Model) for
each basin using a 10 year 1 day design storm event of 7” inches of rainfall, the 25 year
3 day design storm event of 12” inches of rainfall, and the 100 year 3 day storm event of
14” inches of rainfall. The design storm rainfall totals are from the SFWMD, Volume IV,
Surface Water Design Aids, Figures C-6, C-8, and C-11 (see Appendix – Rainfall
Information).
The stormwater model results show maximum stages within each basin for the design
storms. These stages were compared to the existing contours within the basin to
determine the potential level of flooding.
The modeling effort is based on available information and has not been calibrated using
actual specific soil test data or specific elevations within the existing basins. Therefore,
the results of the modeling provide general information on potential areas of concern. In
order to conduct an in-depth analysis, it would be necessary to obtain specific
geotechnical information and to perform field survey the areas in question.
4.5 STORMWATER SYSTEM LEVEL OF SERVICE DEFICITS
Approximately 40% percent of the area within the Port Salerno CRA is served by
existing conveyance and flood protection facilities providing an adequate LOS.
Areas within the Port Salerno CRA currently not served by regional conveyance and
stormwater treatment areas/systems are considered to be deficient relative to the LOS
definition. In addition, there are a number of areas serviced by inadequate infrastructure.
While these systems are sufficient for providing the daily drainage needs of the area,
they are insufficient when compared to the current LOS criteria needed for water quality,
stormwater attenuation, and basic flood protection.
In addition to the LOS considerations, the analysis included a review of nuisance
flooding concerns. Although most residents do not have structure flooding, they may
encounter nuisance ponding in front of their homes and businesses. It should be noted
the cost of removing all the nuisance ponding may be expensive and the benefit to the
drainage systems LOS may be minimal.
In discussions with Martin County staff, several areas of concern were identified.
Specific information on these areas is shown Section 4.6, Summary of System Deficits.
The American Red Cross provided information related to flooding during 1995, 1999,
and 2000. The Martin County Health Department did not indicate specific concerns
about failed onsite sewage disposal (septic) systems within the Port Salerno
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EXISTING CONDITIONS AND NEEDS (07/03/06)

Redevelopment Area. However, the area is identified as a wastewater system deficiency
but is also an indication of stormwater concerns due to high water table levels affecting
the operation of the septic systems.
In addition to analyzing the existing data, stormwater modeling of the general existing
conditions has been conducted to confirm the existing deficiency information or identify
other potential deficient areas. Methodology for existing conditions analysis is shown
below in Section 4.4.
Figure 13, “Existing Stormwater System Deficits” delineates the existing stormwater
and conveyance system areas within the Port Salerno CRA identified as stormwater
deficiencies by either Martin County staff, other regulatory agencies, or by site
observations.
4.6 SUMMARY OF STORMWATER SYSTEM DEFICITS
A summary of deficiencies in the stormwater system is listed below in Table 4.6-1. This
includes deficiency criteria on hydraulic performance, structural integrity and nuisance
concerns. Each adverse condition identified during the assessment has been tabulated
for each of these three categories.
*Table 4.6-1
Areas of Existing Stormwater Needs
LOCATION CONDITION
Flooding in the area of S.E. 48
New Monrovia
th Avenue and S.E. Field Street
No stormwater infrastructure and local intersection and street
Rocky Point
flooding
No water quality, conveyance, or flood protection in compliance
Port Salerno (North of S.E. Salerno Rd.) with above.
Existing swales need continued maintenance; Salerno Creek from
Ebbtide Road to S.E. Dixie Highway; the Port Salerno Elementary
CRA wide maintenance
School ditch
Fifty six (56) percent of the CRA has no known formal water
quality treatment or traditional methods of flood protection. This
includes developments constructed prior to 1979 that are not in
Overall CRA Area Water Quality the 2 retrofitted basins.
* See Figure 13 – “Existing Stormwater System Deficits”
4.7 CRA PROJECT STORMWATER NEEDS
Fifty six percent of the CRA does not have adequate stormwater facilities to provide the
minimum treatment required by the Martin County land Development code or to comply
with the SFWMD water quality requirements. Large areas of the CRA need to be
studied to determine the best way to increase the LOS provided for stormwater quality
and attenuation.
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EXISTING CONDITIONS AND NEEDS (07/03/06)

Each of the neighborhoods previously mentioned are identified in the Port Salerno
Community Redevelopment Plan, and each has a project which is proposed to enhance
the quality of life in the neighborhood. This section of the report will expand upon the
stormwater needs and opportunities associated with specific projects identified in the
Community Redevelopment Plan.
4.7.1 New Monrovia
Flooding occurs at SE 48 th Avenue, SE Field Street, and SE Front Avenue S, according
to records of Martin County and the American Red Cross. A need exists to improve
drainage in the existing ditches paralleling SE 48 th Avenue, between SE Field Street and
SE Murray Street. There are lots available for surface water quality improvements due to
55% of the subdivision consisting of vacant lots.
4.7.2 Rocky Point
The Rocky Point neighborhood is in need of a retrofit program to provide water quality
treatment for storm runoff in the area: improvements will be designed and permitted
through the agencies as outlined in Section 3. Stormwater exfiltration trenches could be
used to create an acceptable and workable system for the community. Exfiltration
trenches are a compatible Best Management Practice (BMP) promoting aquifer
recharge, while reducing runoff and treating stormwater. Legal positive outfalls should
be identified to allow the runoff to discharge after being treated. Opportunities exist to
incorporate certain remedial stormwater plans addressing existing deficiencies.
4.7.3 Port Salerno
While the Salerno Creek Stormwater Quality Retrofit considered 179 acres of the CRA,
additional improvements are needed. Projects which alleviate localized street flooding
and improve connections to the Salerno Creek Stormwater Quality Retrofit project are
needed. The intersection of SE Broward Street and SE Driftwood Avenue is known to
flood. Salerno Creek east of SE Ebbtide Avenue, needs to have the pervasive stand of
Brazilian Pepper removed as well as remedial work to replant and restore the banks.
North of SE Salerno Road, the Port Salerno elementary School ditch should be enlarged
and maintained. Other roads in the subdivision also have flooding problems requiring
attention. Roads without drainage improvements, such as, SE Isabelita Avenue between
SE Seaward Street and SE Salerno Road, should have swales or underground storm
systems. A 60’ right-of-way exists which could support a swale system, according to the
Martin County Land Development Code.
4.7.4 Manatee Creek
The Manatee Creek residential area’s stormwater quality needs have been met by the
Manatee Creek Stormwater Quality Retrofit Study. However, most of the streets are
dead-end streets needing to be properly connected to the water quality improvements
being constructed.
4.7.5 Additional Basin Studies
Hydrological, geographical, and political boundaries frequently differ. The Port Salerno
CRA is in seven drainage basins: all of the basins extend beyond the political and
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EXISTING CONDITIONS AND NEEDS (07/03/06)

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.
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EXISTING CONDITIONS AND NEEDS (07/03/06)

4.8.3 Port Salerno
The Port Salerno Elementary School Ditch would be enlarged to contain the 25 year 3
day storm event within its banks. Streets draining into the ditch should have swales
improved to enhance attenuation. Credit for 20% of the required water quality treatment
can be obtained if the swales are dry. The 60’ foot rights-of-way can be used for swales
according to the County land Development Code. There are four vacant lots between SE
Isabelita Avenue and SE Grouper Avenue, which may be acquired to provide additional
storage and treatment to augment the treatment provided in the swales.
4.8.4 Manatee Creek
The Manatee Creek Stormwater Quality Retrofit will provide water quality treatment for
197 acres of the CRA; construction of the recommended Phase I improvements will
begin in spring of 2006. It is anticipated hydraulic connectivity in Manatee Creek will
continue to be a problem.
4.8.5 Overall Stormwater Quality Port Salerno CRA
To fully address the overall stormwater quality for the existing area, the area will need to
follow the master plan as proposed and provide Stormwater Treatment Areas (STA)
throughout the region. As a result of the ongoing Salerno Creek and Manatee Creek
retrofits, issues will be resolved at the subsequent completion of the project for 44% of
the Port Salerno CRA.
4.9 RECOMMENDED IMPLEMENTATION
The recommended improvements developed in this analysis, are a combination of LOS,
water quality, and nuisance improvements. The improvements will be phased into the
overall CRA improvements as development occurs. In areas where health, safety and
welfare concerns are critical, immediate attention will be required. In order of
importance, these areas are:
1. Additional Basin Studies
2. Port Salerno (north of S.E. Salerno Road)
3. New Monrovia
4. Rocky Point
5. Manatee Creek
6. Additional Basin Studies
MARTIN COUNTY STORMWATER/UTILITY CRA MASTER PLAN – PORT SALERNO CRA SECTION 4-9
EXISTING CONDITIONS AND NEEDS (07/03/06)

4.10 SUMMARY OF OVERALL STORMWATER NEEDS OF THE PORT SALERNO
COMMUNITY REDEVELOPMENT AREA
The stormwater needs in the Port Salerno Community Redevelopment Area were
assessed based on the water quality and water quantity criteria described in Section 3
Governing Rules and Regulations. The CRA’s existing conditions indicate treatment of
stormwater runoff for water quality is formally lacking: it is evident by the deficient
stormwater infrastructure in the CRA, compared to the immediate surrounding areas of
newer development. Attenuation of peak discharge rates after storm events is currently
not provided in 56% of the CRA due to the lack of a local or regional stormwater system
to protect streets from flooding and property from damage.
4.11 EXISTING WATER SYSTEM
4.11.1 Existing Water System
The Port Salerno CRA is currently supplied water from Martin County Utilities and Solid
Waste (a.k.a. Martin County Utilities). According to Martin County Utilities, they provide
water to 25,000 households and 1,500 commercial developments in unincorporated
Martin County, Ocean Breeze Park and Sewall’s Point. Potable water demands are
currently met through four water treatment plants; Martin Downs, North County, Tropical
Farms, and Vista Salerno; which are located throughout the County.
An inventory of the Martin County Utilities water lines are included in Table 4.11-1, for a
total of 658,750 linear feet of piping.
Table 4.11-1
Water Line Pipe Inventory*
Water Line Inventory* Length
6” inch 61,187 ft
8” inch 169,967 ft
10” inch 62,373 ft
12” inch 232,554 ft
16” inch 121,213 ft
20” inch 8,969 ft
24” inch 2,487 ft
Total Length 658,750 ft
*Source: Martin County Water CAD hydraulic model of the system in 2003.
The existing water system includes 2” inch, 3” inch, and 4” inch PVC waterlines.
However, they were not modeled since fire hydrants require a minimum 6” inch line to
provide pressure for fire fighting purposes.
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EXISTING CONDITIONS AND NEEDS (07/03/06)

Current County customers in the Port Salerno CRA are served through two major trunk
lines. A 16” inch water line runs along SE Dixie Highway and a 20” inch water line runs
along SE Cove Road as shown in Figure 8, “Existing Water Piping.” The development
of Figure 8 was based on information extracted from the electronic Utility Atlas supplied
by Martin County Utilities, which graphically depicts the current water lines in the Port
Salerno CRA.
4.11.2 Summary of Water System Needs
Customers within the CRA served with existing water, are generally provided with an
adequate LOS. No known operational deficiencies, such as low operational pressures or
fire flows in the water system, have been identified in our discussions with the utility
provider.
Areas currently not served by central water service, are considered to be deficient
relative to the LOS definition. In addition, there are a number of areas serviced by 2”
inch, 3” inch, and 4” inch diameter water mains. While these lines may be sufficient for
providing the daily needs of the customer, they are insufficient when compared to the
minimum 6” inch diameter fire flow needed to support basic fire service; unless a hydrant
is fed from a 6” inch line in close proximity of the structure.
4.12 EXISTING SANITARY SEWER SYSTEM
4.12.1 Existing Sanitary Gravity Sewer System
Martin County Utilities provides wastewater within unincorporated Martin County,
Seawall’s Point, and Ocean Breeze Park. Only part of the CRA is currently connected to
a centralized sewer system. These areas include the neighborhoods of Manatee Creek,
Murray Cove and Bollard Avenue.
4.12.2 Existing Sanitary Forcemain Transmission System
Port Salerno is located in Martin County Utilities South Wastewater System. The south
system consists of the Tropical Farms, Parkwood, Rocky Point and North A1A service
areas. Currently, the wastewater system is interconnected, where flows are divided
between the Dixie Park Wastewater Treatment Plant and the Tropical Farms
Wastewater Treatment Plant. Martin County Utilities plan to take the Dixie Park
Wastewater Treatment Plant off-line (out of service) in the future, leaving Tropical Farms
Wastewater treatment Plant the only facility in the south system. Dixie Park will be used
as a master re-pumping station to redirect flows from the east side of the service area to
the west for treatment.
There are several lift stations within the CRA boundary; most are located in the SE
section of the CRA. All the lift stations pump to an 8” inch or 6” inch forcemain: the
majority of which pump to the Dixie Park WWTP. The lift station west of the Murray
Middle School, has the option of being redirected to the Tropical Farms Wastewater
Treatment Plant by shutting-off the forcemain valve near the School.
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EXISTING CONDITIONS AND NEEDS (07/03/06)

4.12.3 Sewer System Needs
The majority of the residences/lots within the CRA boundary lack connection to a
centralized sewer system. The exceptions being the Manatee Creek and Murray Cove
neighborhoods, as well as an 8” inch sewer main of Bollard Avenue. There are some
private lift stations for some commercial and institutional buildings. In an effort to
connect the CRA to the South System, a comprehensive wastewater collection system
will have to be designed, permitted, and constructed.
4.13 WATER AND WASTEWATER SYSTEM LEVEL OF SERVICE DEFICITS
Areas currently not served by central water and sewer service are considered to be
deficient relative to the LOS definition. There are a number of areas serviced by 4” inch
and 2” inch diameter water mains. While these lines may be sufficient for providing the
daily needs of the customer, they are insufficient compared to the minimum 6” inch
diameter pipe needed to support basic fire service, unless a hydrant serviced by a 6”
inch line is in close proximity of the structure.
Figure 8, “Existing Water Piping”, delineates the existing central water piping system
within the CRA as reported by Martin County Utilities. The water piping shown in the
exhibit is limited to 6” inch diameter and larger. Areas shown in the exhibit which do not
have existing piping are considered to be deficient in accordance with the LOS
standards.
Figure 9, “Existing Wastewater Piping”, delineates the existing wastewater piping
system within the CRA as reported by Martin County Utilities. The gravity portion of the
sewer system installed does not have any known service deficits. According to the
March 2000 Forcemain System Hydraulic Analysis by Hutcheon Engineers, 100% of the
lift stations within the CRA boundary are able to deliver the required flows during peak
flow conditions.
4.14 LEVEL OF SERVICE RECOMMENDATIONS FOR WATER AND WASTEWATER
Level of Service (LOS) standards for the water and wastewater systems are identified
through a combination of engineering standards, utility purveyor policies, community
practices, and regulatory requirements as presented in Section 3. Throughout the CRA
area (as well as other areas of the County) there are large tracts of land lacking central
water service and rely on individual wells for their water supply. Similarly, there are
large areas which do not have access to a central sewer system and utilize on-site
septic systems to dispose of their sewage.
The intent of the CRA utility redevelopment process is to: provide central water and
sewer service to all parcels within the CRA; provide consistent quality potable water to
all residents; provide sufficient fire flow to respond effectively to emergencies; and,
eliminate operational and environmental problems associated with on-site treatment
systems. Accordingly, the basic LOS standard for all areas within the CRA incorporates
the following:
MARTIN COUNTY STORMWATER/UTILITY CRA MASTER PLAN – PORT SALERNO CRA SECTION 4-12
EXISTING CONDITIONS AND NEEDS (07/03/06)

− Centralized potable water service to supply the consumptive needs of all
parcels within the service area
− Minimum fire flow to every parcel consistent with the potential use of all
parcels
− Centralized Sewage collection service for all parcels
Inherent in providing the LOS standards are implied minimum design standards utilized
for sizing the pipes and related facilities. Design standards are developed from a
combination of: national standards; Martin County policies and practices; and, regulatory
requirements and guidelines. These include the following:
1) Water systems
a. Minimum 6” inch diameter water lines – In order to provide a basic
level of fire protection, fire hydrants are required to be connected to
minimum 6” inch diameter water lines. A number of areas within the CRA
have 2” inch and/or 4” inch diameter lines which can provide basic water
service but do not provide adequate flow for fire protection.
b. Provide Fire Hydrant availability to all Parcels – Installation of fire
hydrants at approximately 500’ foot intervals ensures adequate hydrant
availability for each structure.
c. Minimum system pressure under peak flow condition is 40 pounds
per square inch (psi) – During the maximum anticipated flow condition,
minimum pressure requirements at the point of the service connection
provides sufficient pressure to adjacent structure plumbing systems.
d. Minimum system pressure under fire flow condition is 20 psi –
During a fire, the minimum requirement for 40 psi at the service
connection is relaxed to 20 psi for the period required to respond to the
fire. Unless unusual conditions require special consideration, it is
assumed the fire flow event is run in conjunction with Maximum Day Flow
on the system, rather than the peak flow condition.
e. Fire Flow Requirements – Minimum standards include providing a 500
gallon per minute (GPM) fire flow to single family residential areas and a
maximum fire flow demand of 1500 GPM to non- residential areas. While
many areas of the system can obtain larger fire flows, this is the
maximum the system would deliver at the most remote point on the
anticipated day of the year with the highest water demand. Demands in
excess of this amount may require additional pumping or storage on site.
2) Wastewater systems
a. Wastewater Service provided by central collection system – A
number of areas within the CRA boundary have an on-site treatment
system (septic tanks or small package plants). It is the intent of this
project to eliminate the on-site treatment systems and tie the customers
into the central sewer system as a basic LOS.
MARTIN COUNTY STORMWATER/UTILITY CRA MASTER PLAN – PORT SALERNO CRA SECTION 4-13
EXISTING CONDITIONS AND NEEDS (07/03/06)

. Minimum 8” inch diameter gravity line – In accordance with generally
accepted engineering standards (Florida Department of Environmental
Protection Regulations, Ten State Standards, and the Water Pollution
Control Federation Manual of Practice) the minimum acceptable diameter
sewer line in a system is 8” inch diameter. The vast majority of the sewer
lines to be installed in the CRA area project would fall into this category.
c. Minimum four 4” inch diameter force main – In accordance with
generally accepted engineering standards Florida Department of
Environmental Protection Regulations, Ten State Standards, and the
Water Pollution Control Federation Manual of Practice) the minimum
acceptable nominal diameter sewer line in a force main is 4” inch
diameter.
d. Maximum Manhole spacing of 400’ feet – This standard is set by Martin
County Utilities and is determined by the maximum length of pipe
cleaning equipment available to the system operator.
MARTIN COUNTY STORMWATER/UTILITY CRA MASTER PLAN – PORT SALERNO CRA SECTION 4-14
EXISTING CONDITIONS AND NEEDS (07/03/06)