EAC Backup 06/05/2013 TRANSMITTAL MEMORANDUM
DATE: June>. 2013
TO: Collier County Board of County Commissioners
Collier County Planning Commission
FROM Andrew Dickman, Chair 2-
Collier County Environmental Advisory Council
RE: Low Impact.Development
Pursuant to Section 2-1193(a) of the Collier County Code of Ordinances, the EA.0 is authorized
to "Identify, study, evaluate, and provide technical recommendations to the BCC' on programs
necessary.for the consenvation, management, and protection of air, land, and water resources
and environmental quality in the County,"
Please find attached the EAC's report on low impact development strategies that will reduce the
impact on the public stormwater management system,and ultimately help prevent pollution from
damaging water resources and fragile coastal ecosystems.
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LOW IMPACT DEVELOPMENT
Introduction.
The environmental Advisory Council is fully committed to doing whatever it can, within
its jurisdiction, to clean and protect Collier's water resources. This environmental report
seeks to implement Collier's multimillion dollar "Watershed Management Plan"
("WMP").
Legal Basis
Pollution discharge into natural water systems is a nationwide and local concern. "The
objective of this Act is to restore and maintain the chemical, physical, and biological
integrity of the Nation's waters." Clean Water Act,33 U.S.C. §1251 et seq. (1972).
[T]he comprehensive plan shall include ... [a] conservation element for the conservation,
use, and protection of natural resources in the area, including air, water, water recharge
areas, wetlands,waterwells, estuarine marshes, soils, beaches, shores, flood plains, rivers,
bays, lakes, harbors, forests, fisheries and wildlife, marine habitat, minerals, and other
natural and environmental resources, including factors that affect energy conservation. §
163.3177(6)(d), Fla. Stat. "Required and optional elements of comprehensive plan..."
Goal 2: "To Protect the County's surface and estuarine water resources." Collier County
Growth Management Plan, Conservation and Coastal Management Element [need to
confirm new language].
Collier County Watershed Management Plan
The WMP's first, non-structural, and least expensive, recommendation is the adoption of
a Low Impact Development (LID) Program. Unfortunately, a LID policy in not in the
County's Growth Management Plan,nor are there LID land development regulations.
LID is a well established progressive approach to stormwater management that relies on
hydrology-based site planning and design. LID aims at minimizing the volume of runoff
and associated pollutants reaching the receiving water bodies and managing it as close as
possible to where it is generated. Techniques defined as micro-controls are implemented
in a dispersed fashion throughout a site.
The basic principle is to attempt to mimic pre-development hydrology by retaining or
treating stormwater runoff close to the source thereby replicating the natural pathways.
Examples of LID techniques include a) use of pervious pavement to minimize runoff
volume; b)construction of rain gardens, localized infiltration areas, or created systems of
filter marshes to treat stormwater runoff; c) storage and re-use of stormwater for
irrigation purposes; and d)minimizing the extent of the directly connected impervious
area hydraulically connected to the stormwater conveyance system, and thence to a
basin's outlet point, without flowing over pervious areas.
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The implementation of the proposed LID program is expected to be, at worst, cost neutral
for the development community. The main benefit of implementing the proposed
program is the achievement of countywide water quality improvements of the County's
water bodies due to pollution load reductions,recharge of groundwater, and reduced fresh
water releases to estuaries.
Research has shown the watershed imperviousness has a direct relationship to stream and
receiving water degradation. In addition, as indicated previously, exclusive reliance on
conventional structural techniques is not allowing streams and receiving waters to meet
water quality standards. Studies for the WMP revealed that four of five major estuaries
in Collier County do not meet clean water standards. Therefore, a new approach based
on the preservation of a site's natural features has been found to be an effective way to
minimize pollution loads and help preserve the natural system.
Growth Management.
Federal and State laws require Collier County to restore polluted waters and protect
vulnerable natural resources. Anticipating future growth, Collier County adopted policies
to protect surface and estuarine water resources. A LID program must be codified in the
County's Growth Management Plan and implemented in the land development codes
(LDC) that implement the Growth Management Plan. All advisory boards should make
recommendations to incentivize LID tools when reviewing development proposals. Land
use decisions are critical to the success of a LID program and clean water resources.
Intra County and Regional Coordination.
Collier County is diverse. With urbanized, rural fringe, rural, agricultural, and
conservation areas. We have both incorporated cities and unincorporated areas. Growth
management and stormwater management coordination is imperative. Uncoordinated
decisions in one area likely will impact other areas. Preparation for population growth
countywide within planning areas is vital. Conversely, it's useful to understand how
other counties in our region accommodate development and manage stormwater. The
following provides a snapshot of regional stormwater/LID strategies and offers
recommendations for Collier County.
The Collier County Board of County Commission has "accepted"the WMP that
contains significant LID recommendations. The County has formed a staff-level
working group to implement the LID strategies from the WMP. The current
implementation strategy is to compile LID practices that conform to Collier
Collier County's hydrogeological conditions into a manual for use by the development
County community on a voluntary basis (September 2013); identify incentives to
propose to stakeholders for their input (November 2013); finalize input from
stakeholders (February 2014); prepare staff recommendations for LDC
Amendments, if needed, and prepare materials as needed to conform to the LDC
Amendment cycle schedule (March 2014.)
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While Lee County does not specifically name LID as non-structural strategies,
several goals, objectives and policies in the "Lee Plan" promote green
infrastructure and protection of natural resources:
OBJECTIVE 60.5: INCORPORATION OF GREEN INFRASTRUCTURE
INTO THE SURFACE WATER MANAGEMENT SYSTEM. The long-term
benefits of incorporating green infrastructure as part of the surface water
management system include improved water quality, improved air quality,
improved water recharge/infiltration, water storage, wildlife habitat, recreational
opportunities, and visual relief within the urban environment. (Added by
Ordinance No. 03-06).
GOAL 61: PROTECTION OF WATER RESOURCES. To protect the county's
Lee water resources through the application of innovative and sound methods of
County surface water management and by ensuring that the public and private
construction, operation, and maintenance of surface water management systems
are consistent with the need to protect receiving waters.
OBJECTIVE 61.2: MIMICKING THE FUNCTIONS OF NATURAL
SYSTEM. Support a surface water management strategy that relies on natural
features (flow ways, sloughs, strands, etc.) and natural systems to receive and
otherwise manage storm and surface water.
OBJECTIVE 61.3: GENERAL SURFACE WATER MANAGEMENT
STANDARDS. Lee County will continue to provide sufficient performance
and/or design standards for development protective of the function of natural
drainage systems. (Amended by Ordinance No. 94-30, 00-22)
Numerous LID objectives and policies are promoted through the Charlotte
County Comprehensive Plan, Stormwater Management Element.
SWM Objective 3.3 Low Impact Development and Green Infrastructure
To achieve long-term benefits such as improved water quality, improved air
quality, improved groundwater infiltration and recharge, increased water
storage, expanded wildlife habitat, expanded recreational opportunities and
Charlotte visual relief within the urban environment by incorporating low impact
Count development design criteria and green infrastructure as part of the stormwater
y management system.
SWM Policy 3.3.1 Low Impact Development Effort
The County, in partnership with other government, non-profit, and private
entities, shall seek grant funding to establish a Low Impact Development (LID)
research and training facility to clarify best local area practices and to educate
the public and the development community about sustainable site development
best management practices.
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SWM Policy 3.3.2 Low Impact Development Research
Prior to development of a full-scale LID research and training facility, the
County shall establish an LID library and LID advocacy group that will arrange
training from the SWFWMD, and others, that will be responsible for developing
and maintaining the LID research and training facility.
SWM Policy 3.3.3 Low Impact Development Design Criteria
The County shall incorporate LID design criteria, best management practices
(BMPs), and stormwater credits into its Code of Laws and Ordinances and
capital projects practices within one year of the effective date of this
comprehensive plan, and in coordination with State and WMD initiatives.
Pre-design BMPs may include but are not limited to:
1. Tree, topographical,soil, and wildlife surveys;
2. The provision and preservation of native landscaping and natural water
flows;
3. Narrow road designs;
4. The preservation of natural depressions;
5. The conservation of existing vegetation and resulting habitats.
6. Post-design BMPs may include but are not limited to:
7. Bioretention areas, biofilters,and rain gardens;
8. Bioswales or grassed and vegetated swales;
9. Dry wells;
10. Filter buffer strips;
11. Green infrastructure;
12. Green roofs or vegetated roofs;
13. Infiltration trenches;
14. Inlet pollution removal devices;
15. Native landscaping;
16. Permeable or porous pavement and pavers;
17. Rain barrels and cisterns;
18. Soil amendments or soil augmentation;
19. Stormwater planters;
20. Tree planting and tree preservation;
21. Tree box filters;
22. Vegetated buffers; and
23. Wetland restoration.
SWM Policy 3.3.4 Best Management Practices
The County shall encourage new development and redevelopment to design
stormwater management systems to incorporate BMPs including, but not limited
to, filtration marshes, grassed swales planted with native vegetation,
retention/detention lakes with enlar:ed littoral zones,u.land buffers, .reserved
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- or restored wetlands, and meandering flow-ways.
Miami-Dade County has 34 incorporated municipalities. This summary is
focused on the unincorporated jurisdiction of Miami-Dade County.
The County's comprehensive plan does not specifically address the use of LIDs
in stormwater management. Limited information on stormwater management is
available. The County's internet public information describes stormwater
management:
Stormwater is basically a way of describing an accumulation of
rainwater. This rainwater is either absorbed into porous surfaces like
grass, forests, farm fields, and other areas of "open ground," or the
rainwater collects on non-porous (or impervious) surfaces like streets,
parking lots, and rooftops.
It's these impervious areas where rainwater collects that is the
challenge for stormwater planners. In order to keep these impervious
areas from flooding, streets, parking lots and buildings are often
designed with underground pipes and basins that drain this stormwater.
However stormwater managers are faced with three primary
challenges:
Miami- Drain stormwater quickly in order to prevent flooding, and make sure
Dade that stormwater is clean of any contaminants picked up along the way,
County and use that stormwater to recharge our groundwater so that drinking
water supplies will be available.
In addition, these challenges must be accomplished taking into account
existing infrastructure, working within limited space, and using a
limited budget as economically as possible.
Miami-Dade County's strategy for stormwater management is through the use of
a"Utility."
The Stormwater Utility was established in 1991 to properly manage
the environmental impact of stormwater pollution and to provide
adequate flood protection.
The Utility was created to help solve the problem of polluted
stormwater and to improve the drainage capability of areas that are
susceptible to flooding. Reduced open spaces create barriers to
rainwater, limiting the ability of water to soak into the ground and
recharge our aquifer. Special structures need to be built to drain these
areas.
Fees collected by the Stormwater Utility :o toward the .lannin.,
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construction, operation and maintenance of stormwater management
systems in Miami-Dade County — such as canal and drainage
improvement projects and secondary drainage systems in
unincorporated portions of the County and within certain
municipalities.
They also go toward reducing pollution caused by silt, oil, gasoline,
fertilizers, pesticides and other litter carried by the stormwater to the
drainage systems that have been developed to prevent flooding during
heavy rainfall. Stormwater drains not only have to remove water from
the streets as quickly as possible, but they now also have to deal will
all of the contaminants that get picked up along the way.
Stormwater Utility fees are assigned to all developed residential and
non-residential properties and are determined as a function of
equivalent residential units (ERU) for residential properties and by
determining the impervious area for non-residential properties.
Instead of tacking the fee to everyone's property tax, the Utility
measures the size of a given property that is impervious to rainwater
and calculates the fee based on that figure.
That way, the Stormwater Utility is charging a fee based on the runoff
generated from those impervious surfaces (like rooftops and parking
lots), since this runoff is what the Stormwater Utility is going to have
to handle.
Monroe County is required by their adopted Year 2010 Comprehensive Plan to
prepare a Stormwater Management Master Plan. The SMMP emphasizes land
use planning and public education as part of its LID strategy. The PIan
identifies several preferred LIDs.
2.6.2.12 Low Impact Development
Low impact development emphasizes environmental sensitive design
development principles. Applying the principles together, planners, developers,
Monroe and local officials can measurably reduce impervious cover, conserve natural
County areas, and reduce the impacts of stormwater from new development while at the
same time enhancing both the natural environment and community well-being.
Listed below are some examples of low impact development ideas:
1. Residential streets designed for the minimum required pavement width
needed to support travel lanes, on-street parking, and emergency
vehicle access.
2. Reduction of residential street lengths by examining alternative street
la outs.
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3. Minimization of the number of street cul-de-sacs and incorporate
landscape areas to reduce their impervious cover.
4. Where density, topography, soils and slope permit, vegetated open
channels should be used in the street right-of-way to convey and treat
runoff.
5. Reduce excessive parking, minimize stall dimensions, encourage
shared parking, and use pervious materials in spillover parking areas
where possible.
6. Provide stormwater treatment for parking lot runoff using bioretention
areas, filter strips, and/or other practices that can be integrated into
required landscaping areas and traffic islands.
7. Advocate open space design development incorporating smaller lot
sizes to minimize total impervious area, conserve natural areas,provide
community recreational space, and promote watershed protection.
8. Relaxation of setbacks to reduce overall lot imperviousness.
9. Consider locating sidewalks on only one side of the street and
providing common walkways linking pedestrian area.
10. Promote alternative driveway surfaces and shared driveways to reduce
overall lot imperviousness.
11. Direct rooftop runoff to pervious areas.
12. Clearing and grading of forested and native vegetation at a site should
be limited to the minimum amount needed to build lots.
13. Conserve trees and other vegetation at each site by planning additional
vegetation, clustering tree areas, and promoting the use of native
plants.
In 2011, Sarasota County published its "SARASOTA COUNTY LOW-
IMPACT DEVELOPMENT MANUAL." At the same time, the C
comprehensive plan and land development codes implement LID practices unty's
The Manual describes LID as "a stormwater management approach that uses a
suite of hydrologic controls (structural and non-structural) distributed
throughout the site and integrated as a treatment train (i.e., in series) to replicate
the natural hydrologic functioning of the predevelopment landscape."
Sarasota Some site-specific LID integrated management practices included in the:
County
1. Preserve or conserve existing site features and assets that facilitate
predevelopment hydrologic function.
2. Minimize generation of runoff from impervious surfaces (i.e., use peak
and total volume controls) and contamination (i.e., use load controls) as
close to the source as possible.
3. Promote distributed retention, detention, treatment, and infiltration of
runoff.
4. Capture and reuse stormwater on site.
5. Minimize site disturbance and corn'action of soils throu.h low im.act
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clearing, grading, and construction measures.
The stated purpose of the manual is to support "Sarasota County's goal of
applying the LID concept and design where feasible to enhance existing
stormwater management measures and reduce the adverse impacts of land
development projects on the county's natural resources."
Recommendations.
1. Dedicate sufficient funding and staffing to complete the Collier LID strategy
already underway by the staff-level working group described above.
2. Target the following LID techniques for initial implementation: bio retention
swales, pervious pavers, green roofs, stormwater harvesting, sunken landscape
islands in parking lots, and overflow grass parking areas.
3. Create a tax reduction incentive for any property owner that implements approved
LID techniques which reduce the stormwater impact on the public structural
stormwater management systems.
4. Establish an LID public information strategy.
5. Coordinate with the City of Naples to promote LID techniques to clean and
protect shared receiving waters and estuaries that are impacted by polluted
stormwater.
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