DSAC Agenda 05/04/2011 R DEVELOPMENT
SERVICES
ADVISORY
COMMITTEE
MAY 4, 2011
AGENDA
DEVELOPMENT SERVICES ADVISORY COMMITTEE
AGENDA
May 4, 2011
3:00 p.m.
Conference Room 610
NOTICE:
Persons wishing to speak on any Agenda item will receive up to three (3) minutes unless the Chairman adjusts
the time. Speakers are required to fill out a "Speaker Request Form," list the topic they wish to address, and
hand it to the Staff member seated at the table before the meeting begins. Please wait to be recognized by the
Chairman, and speak Into a microphone. State your name and affiliation before commenting. During
discussion, Committee Members may direct questions to the speaker.
Please silence cell phones and digital devices. There may not be a break in this meeting. Please leave the room
to conduct any personal business. All parties participating in the public meeting are to observe Roberts Rules
of Order, and wait to be recognized by the Chairman. Please speak one at a time and into the microphone so the
Hearing Reporter can record all statements being made.
I. Call to Order - Chairman
II. Approval of Agenda
III. Approval of Minutes from April 6, 2011 Meeting
IV. Public Speakers
V. Staff Announcements/Updates
A. Public Utilities Division Update - Nathan Beals
B. Fire Review Update - Ed Riley
C. Growth Management DivisionlTransportation Planning - Jay Ahmad
D. Growth Management Division/Planning & Regulation Update - Jamie French
VI. Old Business
A. Watershed Management Plan Projects and Alternatives [Mac Hatcher]
VII. New Business
VIII. Committee Member Comments
IX. Adjourn
Next Meetina Dates
June 1, 2011
July 6, 2011
August 3. 2011
September 7. 2011
October 5, 2011
November 2, 2011
December 7, 2011
GMD Conference Room 610 - 3:00 pm
GMD Conference Room 610 - 3:00 pm
GMD Conference Room 610 - 3:00 pm
GMD Conference Room 610 - 3:00 pm
GMD Conference Room 610 - 3:00 pm
GMD Conference Room 610 - 3:00 pm
GMD Conference Room 610 - 3:00 pm
April 6, 20 II
MINUTES OF THE COLLIER COUNTY
DEVELOPMENT SERVICES ADVISORY COMMITTEE
MEETING
April 6, 2011
Naples, Florida
LET IT BE REMEMBERED that the Collier County Development Services
Advisory Committee, having conducted business herein, met on this date at
3:00 PM in REGULAR SESSION in Conference Room #610, Collier County
Growth Management DivisionIPlanning & Regulation, 2800 N. Horseshoe Drive,
Naples, Florida, with the following Members present:
CHAIRMAN:
Vice Chair:
William Varian
David Dunnavant
Ray Allain
James Boughton
Clay Brooker
Laura Spurgeon Dejohn
Dalas Disney
Marco Espinar
Blair Foley (Excused)
Reagan Henry
George Hermanson (Excused)
David Hurst
Reed Jarvi
Robert Mulhere
Mario Valle
ALSO PRESENT: Nick Casalanguida, Deputy Administrator, GMD Planning & Regulation
Judy Puig, Operations Analyst - Staff Liaison
Jamie French, Director ~ Operations & Regulatory Management
Jay Ahmad, P.E., Director ~ Transportation Engineering
Ed Riley, Fire Code Official- Fire Code Office
Nathan Beals, Project Manager - Public Utilities
Claudine Auclair, Manager - Business Center
Amy Patterson, Impact Fee and Economic Development Manager
April 6, 20 II
I. Call to Order:
Chairman William Varian called the meeting to order at 3:05 PM and read the
procedures to be observed during the meeting.
II. Approval of Al!:enda:
Chanzes:
. Under Item VI, "Old Business" ~ add topic
A. Approval of Utilities/RPZ Subcommittee Minutes from January 7, 2011
B. RPZ Discussion - David Dunnavant, Subcommittee Chair
Marco Espinar moved to approve the Agenda as amended. Second by Robert Mulhere.
Carried unanimously, 9 - O.
III. Approval of Minutes - February 2, 2011 Meeting:
Robert Mulhere moved to approve the Minutes/or the February 2, 2011 meeting as
submitted. Second by Clay Brooker. Carried unanimously, 9 - O.
IV. Public Speakers:
(Will be heard when Item is discussed.)
V. Growth Manal!:ement Division - Staff Announcements/Updates:
A. Public Utilities Division: Nathan Beals, Project Manager - Public Utilities
. No updates to announce
. There were no questions
(David Dunnavant, Laura Spurgeon De John, and Dalas Disney arrived at 3.'08 PM)
B. Fire Review: Ed Riley, Fire Code Official- Fire Code Office
. Monthly Activity Reports for January and February were submitted.
. Reviews conducted: January - 633 and February - 560
Conceming the pending move, Mr. Riley explained the Fire Code Office will make
two trips per day to pick up/drop off Plans until the system becomes digital.
. Regarding computer system: will use "C-D Plus" until "City View" is ready
. Will also use a program entitled "Mobilize" to email review comments
. Anticipated move-in: early May
. Fire Code Office will have a new telephone system and new numbers
Public Speaker:
Kathy Curatolo, CBIA, asked ifthere will be a decrease in review fees.
Ed Riley replied an analysis for the planning side is in process and the overall fee structure
will be reviewed. An analysis for the building side has not yet begun. He noted the Fee
Schedule has not changed since 2003.
2
April 6, 2011
(Reed Jarvi arrived at 3: 15 PM)
C. Transportation Planning Division: Jay Ahmad, P.E., Director - Transportation
Engineering
. The Davis/Collier Project received three (3) bids from Industry
. Bids were opened on March 30th
o Winning bid - $28.2M
o Approximately 19.7% below the County's estimate
. There is a Joint Participation Agreement ("JPA") with the FDOT ("Florida
Department of Transportation") in the amount of $20M
o Collier County will be reimbursed - 10 quarterly payments - commencing
in July 2012
Q. Is the low bidder the same contractor used for Vanderbilt Beach Road who was so
difficult?
A. No, and this Contractor has completed three other projects for the County.
Mr. Ahmad noted the County is in litigation with the former Contractor of the
Vanderbilt Beach Road project.
D. Planning and Regulation: Jamie French, Director - Operations & Regulatory
Management
. With reference to the County's interface with the Fire Code Office computer
system, "City View" will incorporate "Terminal Services" to control the flow
of information on the network and prevent contamination by viruses
. The Fire Code Office will be required to pay for the licensing to access "City
View" as a temporary solution ($511 per month)
. Goal: to avoid redundancy of work between the two systems, and to automate
them
. "City View" went through the validation/testing period and found 100+ issues
which are being reviewed/corrected
o Will not "go live" until May 15th
o Will run both systems ("C-D Plus" and "City View") in parallel
. Will not add staff - may contract "outside" help, as needed
Chairman Varian mentioned problems using the AIRS system/inspection call-in.
The system has been down frequently.
Mr. French noted it was converted from "Windows 95" to "Windows 981XP" and will
be converted to "Windows 7" in the near future. He was not aware anyone had been
experiencing problems connecting to it and stated when "City View" goes live, AIRS
will no longer function.
Jamie French stated he will appear before the Board of County Commissioners
regarding a change to the Fee Schedule concerning payments and refunds.
. Proposed change: collect 50% of fees at application and the balance at the Pre-
Construction Meeting (Land Development services)
. There is a provision in the Land Development Code, under Section RR of the
Fee Schedule, that allows the County to issue up to a 50% refund for those
3
April 6, 2011
Land Development services (inspections/reviews for SDP and SDPI) that were
not completed as long as an application for refund was made within thirty days
of withdrawal of the project
. The County Attorney's Office suggested removing the 30-day time limit from
the Fee Schedule
Mr. French requested direction ffom DSAC.
Dalas Disney concurred, stating if the work has not been done, the Contractor/Builder
(i.e., Applicant) should receive a refund, and suggested the following language:
"incomplete work will be refunded to the extent that funds are available. "
Mr. French stated he was more comfortable tying any refund to the cost of services
provided. He continued the Fee Schedule will continue to be reviewed. The subject of
whether or not another Fee Schedule Study is necessary can be discussed at the next
DSAC meeting.
A question was asked concerning the number of refund applications received.
Mr. French stated approximately $130,000 had been budgeted to cover the requests
which were 13 I-based Fees.
Objective: To draft language that will outline a pattern of practice to allow the Growth
Management Division to handle refund requests administratively, rather than submit
each one to the BCC via an Executive Summary.
It was suggested to compare Collier County's Fee Schedule with other Counties at the
next Fee Schedule review.
VI. Old Business:
A. Approval ofUtilities/RPZ Subcommittee Minutes of January 7, 2011
(Note: David Dunnavant, Melissa Ahern, Joey Hatfield, David Hurst, and Chris Mitchell
attended the Subcommittee meeting. They were present at the DSAC meeting and eligible
to approve the Minutes.)
Subcommittee Chairman David Dunnavant moved to approve the minutes of the
UtilitiesIRPZ Subcommittee meeting held on January 7, 2011 as submitted.
Second by David Hurst. Carried unanimously, 5 - O.
B. RPZ Discussion - David Dunnavant, Subcommittee Chairman
Three primary issues were discussed during the Subcommittee meetings.
. The issue of a Fire-line Service charge vs. a Fire-line meter is "on hold"
David Dunnavant stated the BCC asked the Subcommittee to examine the issue of
RPZ ("reduced pressure zone") back-flow device put in place by Utilities over the
objections ofDSAC.
4
April 6, 2011
He outlined the following:
. The RPZ has been presented as the safest back-flow device and its use would
place Collier County in an elite realm among municipalities.
. There is a signiticant cost to Industry to install RPZs.
. The American Water Works Association recommends that, unless there is a
known contaminate in a water supply system, there is no real need for RPZs.
. Collier County's water supply has been adequately protected for the past 30 to
40 years by the Double Detector Check Valve system.
. The Subcommittee has not been convinced that the improvement to the existing
system warrants the substantial, additional cost.
. There is no current problem - no inherent danger has been substantiated.
. The Subcommittee reviewed the documentation presented by Utilities and did
not reach the conclusion that RPZs are necessary.
David Hurst confirmed, as an engineer who has been dealing with the issue for the
past twelve years, an RPZ would be an improvement to any system. He stated the
main questions were: (I) "Does the "benefit" outweigh the cost~" and (2) "Is there
truly an imminent danger to the County's water system?" He continued that, based on
his observations, the benefit was not measurable while the cost to the Industry could be
substantial (meter cost, increased pipe size due to pressure drop, and changes to design
parameters). His conclusion was installation of RPZs as not warranted. He
volunteered to assist in compiling a formal presentation.
David Dunnavant stated the claim of inherent danger to the County's existing system
was not substantiated and the Subcommittee did not understand why it was necessary
to pursue additional costs.
He further stated the issue of pressure was under review and tabled until the results
from a one-year test (jointly conducted by Fire and Utilities) were available for review.
He noted there were no statistics presented concerning problems created under the
current system.
Chairman Varian asked if there was a motion to recommend to the Board of County
Commissioners.
Clay Brooker asked about the direction from the Board of County Commissioners.
David Dunnavant explained DSAC was directed to return with a report on whether
DSAC recommended the implementation or retaining the RPZs that Utilities put into
place as a required standard.
David Hurst noted the RPZ requirement is currently "on-hold."
David Dunnavant stated that based on the discussions of the Subcommittee and on the
minutes, he asked ifDSAC could make a recommendation to the Board that the
currently "on-hold" ("stayed") adopted RPZ requirement is not supported by Industry
and we ask that it be removed from the requirement and the previous, long-standing
system of Double Detector Check Assembly Valves remain.
Chairman Varian asked Mr. Dunnavant if the previous statement constituted his
Motion and he agreed. Second by David Hurst.
5
April 6, 2011
David Dunnavant reiterated if the RPZ requirement was adopted, it would place
Collier County in the top 1 to 2% of jurisdictions in the entire country.
David Hurst confirmed it (RPZs) was not the norm for the application.
Dalas Disney stated the issue was presented at one time as a Health/Safety and
Welfare issue by Utilities. Because the claim was not supported, he suggested
informing the BCC that "after exhaustive investigation, it has not been presented or
supported in the manner that was previously approved"
David Dunnavant amended his Motion to include that the Health/Safety and Welfare
issue was raised by Utilities but no instances were presented where a Double
Detector Check Assembly Value created a health problem or danger to the citizens of
the community. DSAC does not understand why it is logical and is part of the basis
for recommending the repeal of the adoption {of the RPZ requirementj.
David Hurst stated the back-flow preventer is an enhancement to the system and the
key component to be mentioned is that the lack of an RPZ does not significantly
minimize health of the Collier County community. He concluded he agreed with the
concept ofMr. Dunnavant's amended motion.
Mario Valle noted Utilities stated to the Subcommittee there was an immediate and
imminent threat to public safety yet the Subcommittee did not receive any information
or evidence to support the claim.
DaIas Disney concurred there was a transcript provided of the BCC meeting where it
was asked and answered specifically, "Yes, there is a Health/Safety problem in Collier
County."
[Excerpt from Page 222 of Minutes for BCC's July 27'h Meeting:
"Chairman Coyle: Okay. Now, our Water Department's concern is that
backflow preventers are a safety measure?
Chairman Halas: Health, safety.
Chairman Coyle: And it 's sort of critical that we made some decisions
with respect to that. And if we improperly extend that
decision and something happens and somebody gets
sick as a result of unintended -- or back flow, then we
could be liable
So, now, what i don't understand is, why does it take
90 days for you to develop a position on backflow
pre venters ?" ]
[Excerpt from Minutes ofthe August 27, 2010 Utilities/RPZ Subcommittee Meeting:
"David Hurst: ... 1 was at the Board's meeting. The Board was under the
impression that it was an imminent Health/Safety/Welfare issue. Where they
got that information, I am not sure. But I am positive that was the impression
they were under."]
6
April 6, 2011
Dalas Disney suggested bringing to the Commissioners' attention that the issue was
examined and investigated - the DDCA Valve is in place and has been doing its job.
Installing the RPZs would enhance the system - and spend more money to do it -
when it is apparently not necessary.
David Hurst agreed the Board should be advised the current Health and Safety of the
system is not at risk and would not be substantially improved by the use of RPZs.
Clay Brooker asked Mr. Hurst if the Motion stated no existing threat versus
enhancing, would he second it and he agreed.
David Dunnavant withdrew his Motion and Amended Motion.
David Dunnavant moved as follows:
"The Board of County Commissioners asked DSAC to review the RPZ
adoption by Utilities as a back-flow prevention standardfor Collier County.
After exhaustive study and review, DSAC has determined that there is not
an inherent danger in the current Double Detector Check Assembly Valve
system. Although an enhancement would be provided by the installation of
RPZs, the cost and nominal benefit of the enhancement does not warrant
implementation and the additional expense to the County's citizens.
Thefinal recommendation is that the Board of County Commissioners
repeal the currently adopted Utilities Ordinance which implements RPZs
as the only accepted back-flow device and return to the original Double
Detector Check Assembly Valve ("DDCA'~ system that has been in place
for year. "
Second by Chairman Varian. Carried unanimously, 13 - O.
VII. New Business:
A. Request for Volunteers for Subcommittee to meet/review School Impact Fee
Update Study - Amy Patterson, Impact Fee/Economic Development Manager
. The School Impact Fees, based on a recommendation by the School Board,
were reduced in October 20]0.
. The Impact Fee Study is required to be updated and adopted.
. The 50% reduction in fees will be in place for two years.
Robert Mulhere, Mario Valle and Reed Jarvi volunteered to serve on the
Subcommittee.
B. Review of SDPI / SIPI Process - Claudine Auclair, Manager - Business Center
(A draft copy of the document entitled "Project Request: Application and Submittal
Instructions" was distributed to DSAC.)
7
April 6, 2011
. Determine who will be the reviewer participating in the project
. Goal is to decrease review time - make process faster
. Will need some "tweaking"
Suggestedformat changes:
. Under Step One, "Signature of Agent" and "Date" should immediately follow
signature line (it drifted over one page)
. Under Step Two, insert boxes for choices "Yes" and "No" [_J
. Under Step Four-A, remove the question. It is not clear.
. Under Step Five, specify the applicable Section of the LDC (Land Development
Code)
. Under Engineering, the first sentence is confusing. It should be re-worded.
. Under Transportation, the entire section is difficult to follow and very confusing.
o The last sentence ("Verify this site ...") - remove "current" and substitute
"ADA Guidelines that were valid during construction"
o Additionally, if the engineer did not design it, it cannot be verified
. Under Step Six, the final paragraph should read as follows:
"If NO to any question, then an SDPA or SDPI pre-application
meeting is required. You will be contacted by Staff to arrange
the date and time. Please note that, at the meeting, Staff will
determine if the improvements proposed may be submitted as
an SDPA or if an SDPI is required."
Members were asked to email their comments/suggestions as soon as possible.
Ms. Auclair will present a revised draft at the May 4th DSAC meeting.
c. Vehicle Replacement - Jamie French for Nick Casalanguida
. Maintenance is required for vehicles in service
. There are two vehicles for which repairs exceeded the value
. Intent: (on 113 Fund side) To replace the entire fleet, on an "as needed" basis,
within the next five years
. 2000,2002, and 2004 vehicles are subject to replacement
. The vehicles must be safe for the operators - there is no money in this year's
budget - replacement will be only when absolutely necessary
. There will be capital replacement expenditures in Fiscal Year 2012
VIII. Committee Member Comments:
. David Hurst asked if the web site could be updated to include Bond forms in the
same place as the Application forms
Next Meetinl!: Dates: (Meetings will commence at 3:00 PM unless noted below.)
May 4, 2011
June 1,2011
July 6, 2011
August 3, 2011
8
April 6, 2011
There being no further business for the good of the County, the meeting was adjourned
by order of the Chairman at 5:00 PM.
DEVELOPMENT SERVICES
ADVISORY COMMITTEE
William Varian, Chairman
The Minutes were approved by the Board/Committee on
"as submitted" [---.1, OR "as amended" [_].
,2011,
9
Office of the Fire Code Official
Summary of Plan Review Activity
March-11
Architectural Reviews
Sprinkler Reviews
Underground Reviews
Fuel & LP Gas Reviews
Hoods & FSUP Reviews
Alarm Reviews
SOP Reviews
Total # of Plans Reviewed
Number of Work Days
Average # of Plans Reviewed per Day
ASAP Reviews per Building Department.
Total # of ASAP Reviews.
T alai ASAP Reviews per Day
.Overtime Reviews are nol included in this figure
Scheduled Meetings/Hours
Classes and Seminars attended by FCC
3/30-3/31 Florida Fire Service Caucus
Tallahassee
3/31 Fire Smarts Webinar
NFPA 13 Chapter 8 - 2 CEU's
Total Overtime Hours for the Fire Code Office
.Overtime Hours Reimbursed by Contractors
Ed
Bob
Jackie:
Ricco
Maggie
Participant
Ed Riley
Jackie de la Osa
o
o
In addition to the above-mentioned tasks, The Fire Code Official's Office fields
numerous phone calls, walk.ins, field inspections and impromptu meetings
Office of the Fire Code Official
2800N. Horseshoe Or
Naples, FL 34104
521
60
13
5
12
109
88
808
23
35
1 Architectural Collier County Project
12 Architectural Per County
5 Low Voltage
13 AC Change Outs
6 Tents
37
2
425 Hrs
12.75 Hrs.
9.92 Hrs.
65.83 Hrs.
897 Hrs
Fire Plan Review - Time Frame Summary
March-11
Number Number Average #of 1st %of 1st Percentages
of of Time in Reviews Reviews Within Time
Reviews Days Days Approved Approved Frames
Architectural Reviews
Total .21 800 1.64
1st Review 364 663 1.88 249 68% 100110 Days 7 Day Max
2nd Review 132 91 0.69 100/3 Days
3rd Review 22 25 1.14 100/3 Days
4th Review 3 1 0.33 100/3 Days
Total 2-4 Reviews 157 117 0.75 100/3 Days 3 Day Max
Fire SnrinklAf Reviews
Total 60 37 0.62
1st Review 40 29 073 23 58% 100/10 Days 3 Day Max
2nd Review 16 7 0.44 100/3 Days
3rd Review 3 1 0.33 100/3 Days
4th Review 1 0 0,00 100f3 Days
Total 2-4 Reviews 20 6 OAO 100/3 Days 2 Day Max
Underaround Reviews
Total 13 3 0.23
1st Review 9 2 0.22 4 44% 100110 Days 1 Day Max
2nd Review 3 0 000 100/3 Days
3rd Review 1 1 100/3 Days
Total 2-3 Reviews 4 1 0.25 100f3 Days 1 Day Max
Fuel & LP Gas Reviews
Total 6 2 0.40
1st Review 2 0 0.00 2 100% 100110 Days o Day Max
2nd Review 3 2 0.67 100/3 Days
Total 2nd Review 3 2 0.67 100/3 Days 1 Day Max
Hood & FSUP RAViAWK
Total 12 7 0.58
1 st Review 6 5 0.83 4 67% 100/10 Days 2 Day Max
2nd Review 5 2 DAD 100/3 Days
3rd Review 1 0 0,00 100/3 Days
Total 2.3 Reviews 6 2 0,33 10013 Days 1 Day Max
Fire Alsl1TI RAViAWK
Total 109 78 0.72
1st Review 66 59 0.87 31 46% 100110 Days 3 Day Max
2nd Review 32 13 0.41 100/3 Days
3rd Review 7 4 0.57 100/3 Days
4th Review 2 2 1.00 100/3 Days
Total 2-4 Reviews 41 19 0.46 10013 Days 1 Day Max
SJunmlu:y.
1st Review 4118 778 1.59 313 64% 100/10 Daya
Corrections 231 149 0.65 10013 Days
Overall Totals 720 927 1.29
Office of the Fire Code Official
2800NHors&$hwOr
Naples,FL 34104
CJter County
-.. .........-
- - -
Growth Management Division
Planning & Regulation
Memorandum
To:
Development Services Advisory Committee
From:
Mac Hatcher, Senior Environmental Specialist
Date:
April 26, 2011
Subject:
Staff Summary - May 4, 2011 Watershed Management Plan Workshop Update
Obiective: To initiate discussion on proposed policy and regulation recommendations for the
Watershed Management Plans.
Considerations: I have provided a copy of the memo on the Watershed Management Regulatory
Review which along with the presentation will discuss the need for change, possible incentives, and
recommendations. For general background material the web page has been updated and now contains
summary condition technical memos that will serve as support for the Watershed Plans. I have listed
these documents and included links to these documents from the Watershed Management Plan
Informational links and Documents web page (http://www.colliergov.netllndex.aspx.?page=2302) below:
Instream Water Quality
Surface Water Pollutant Loading
Ground Water Ouality and Loading
Receiving Water Quality
Discharge Water Quantity
Volume and Timing of Fresh Water Discharges
Native Habitat Functional Assessment
Wetland Mitigation within the NGGE Naples Bay watershed
Regulation review and Alternatives
FISCAL IMPACT: There are no fiscal impacts at this time. I will develop fiscal impacts for the
implementation of the watershed plans and ordinances prior to asking for a final recommendation.
GROWTH MANAGEMENT IMPACT: Completion of the WMPs will support objective 2.1 of the
Conservation and Coastal Management Element of the County Growth Management Plan.
PREPARED BY: Mac Hatcher, Senior Environmental Specialist, Growth management Division
/ Planning and Regulation
PBSJ
Technical Memorandum
To: Mac Hatcher, PM Collier County
From: Moris Cabezas, PBS&J
Date: March 31, 2011
Re: Watershed Model Update and Plan Development
Contract 08-5122, PO 4500106318
Phase 2, Element 4: Watershed Management Regulatory Review
1.0 Introduction
An important component of watershed management planning is an analysis of its implementation
within the applicable regulatory framework. The purpose ofthis memorandum is to provide a
description of the current regulations governing stormwater management in Collier County and
present recommendations that would allow implementation of an environmentally sustainable
stormwater management program. The implementation of this management program will guide
future land development activities in Collier County and its implementation is critical to
controlling the potential impacts of development activities on water quantity, water quality, and
natural systems in the watershed. The objectives of the sustainable stormwater management
program are to:
. Promote more effective site planning and minimize anthropogenic impacts to water
quantity and water quality
. Promote preservation of the natural systems
. Help reduce development costs
The regulatory recommendations presented in this memorandum pertain primarily to permitting
requirements addressing County water quality and quantity issues. Recommendations are also
made regarding funding mechanisms, retrofitting public facilities for stormwater management,
and incentives for retrofitting private property.
2.0 Regulatory Background
In Florida, "Waters of the State" are protected per the Water Resources Act, Chapter 373 F.S.
under which permit programs, including those related to surface water management systems and
the Environmental Resource Permit (ERP) process, are established. The ERP process in Collier
County is implemented by the South Florida Water Management District (SFWMD) per Title
40-E of the Florida Administrative Code (FAC). Regulations relate to water quantity, water
quality, and wetland protection/mitigation.
P8SI
Collier County Watershed Management Plan
Surface water management, also referred to as storm water management, is also the responsibility
of local governments, in this case Collier County. The County's Growth Management Plan
(GMP) includes a Public Facilities Element and corresponding Drainage Sub-Element that state
"storm water management refers to a set of comprehensive strategies for dealing with storm water
quantity and stormwater quality issues." County regulations pertaining to stormwater
management are included in various ordinances and the Land Development Code (LDC).
3.0 Regulatory Review
The existing conditions analysis conducted as part of the watershed management planning
process helped assess the magnitude of the anthropogenic impacts in Collier County in terms of
a) hydrology and habitat compared to the natural system, b) water quality in the existing streams,
canals, and estuaries, and c) fresh water discharge patterns to the estuaries. It was concluded that,
in spite of current regulations, the local natural systems have been subject to significant impacts.
In addition, evaluations of the surface water management regulatory framework conducted by
the State of Florida have indicated that under current permitting requirements, impacts of new
development cannot be mitigated.
Numerous structural watershed projects have been analyzed and proposed as part of the
watershed management plan. However, it is clear that structural measures alone will be able to
only partially restore the currently affected natural systems and environment. A change in the
regulatory framework is a critical component of the long-term watershed protection strategy. In
the following section, regulatory changes are proposed that are aimed to help complement the
proposed structural watershed improvement measures. These changes address issues of water
quality as well as water quantity.
3.1 Water Quality
3.1.1 Regulations
Stormwater runoff impacts the water quality in the receiving streams. Minimum standards for
Florida streams have been established based on the designated use of a water body, per the Clean
Water Act. Chapter 62-303 FAC defines the State water quality standards. The condition of a
water body not meeting standards is referred to as "impairment".
The issues of Florida impaired water bodies came to light as part of the recent implementation of
the Total Maximum Daily Load (TMDL) program developed by the FDEP, which requires
identification of water bodies that do not meet applicable State water quality standards. The
process for identifying impaired water bodies is as described in the State's Impaired Waters Rule
(IWR) Chapter 62-303 F AC. As part of that process, fDEP determined that a large number of
water bodies in the State are impaired or potentially impaired. Impairments are particularly
prevalent for nutrients, which have been found to be the most common impairment parameter
throughout Florida. FDEP has found several impaired water bodies in Collier County. A detailed
evaluation ofthe TMDL issues was conducted as part of this project (results are described in a
separate technical memorandum).
PBSJ
2
Collier County Watershed Management Plan
Concurrently with the implementation of the TMOL program, FOEP conducted various studies
to evaluate whether existing technology-based design criteria for storm water systems are helping
meet State Water Policy (62-40.416), under which such systems should be designed to achieve at
least 80 percent reduction of the average annual pollutant loads "that would cause or contribute
to violations of State water quality standards". FOEP's studies demonstrated that current design
criteria for wet detention, which is the most common stonmwater runoff treatment method in
Collier County, generally meet the State Water Policy requirements for removal oftotal
suspended solids. However, nutrient removal efficiencies amount to less than 70 and 45 percent
for total phosphorus and total nitrogen, respectively.
Based on these considerations, FOEP concluded that the current design requirements for
stormwater Best Management Practices (BMPs) are not adequate to meet State law and an
update of the Florida Statewide Stormwater Treatment Rule was necessary. A main requirement
of the proposed updated storm water rule is that post-development pollution loads should not
exceed the pre-development loads. Pre-development is defined as the natural native landscape,
i.e. prior to introduction of canals and control structures. This would necessitate the
implementation of new approaches to remove the additional anthropogenic pollution load,
including the implementation of water quality treatment trains.
The application of the proposed updated FOEP storm water rule would have provided an
effective approach to control water quality impacts of new development. However, it is unlikely
it will be adopted in the near future and current regulatory requirements are anticipated to remain
in place over the foreseeable future and mitigation of development impacts at the local level will
be critical to achieve the County's environmental protection goals.
It must be recognized that implementation of a water quality protection program that enhances
the current penmitting requirements faces a significant challenge due to the limitations of the
current permitting process by the State. Current SFWMO regulations for water quality require
that treatment be provided for one inch of runoff over the developed area or 2.5 inches times the
percentage of imperviousness, whichever is greater. However, no permitting credit is given for
the application of alternative on-site runoff management strategies and/or techniques. With no
incentive, developers are likely to continue traditional designs, which may be more attractive to
potential developers. Consequently, the recommendations presented here are based on
modification to existing requirements coupled with the implementation of incentives.
The Collier County GMP, Conservation and Coastal Management Element, Ordinance 2008-10,
and the LOC Section 3.07.00, require that until the Watershed Management Plans are completed
all new development and re-development projects meet 150 percent of the ERP water quality
volumetric requirements. This interim requirement holds all waters in the County to the same
standards as those applicable to designated Outstanding Florida Waters. This requirement also
reflects the County's intention to provide additional protection to water quality beyond those
provided by the State.
The most commonly used runoff treatment system in South Florida is wet detention. In practice
this has meant that wet detention ponds have been designed to provide an additional 50 percent
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Collier County Watershed Management Plan
of detention time in the permanent pool. It is likely that this modified design has contributed to a
further reduction in the discharge of total suspended solids (TSS) to the County's waters.
However, recent research (ERD, 2007) has found that the removal capacity of nutrients in
detention systems increases at a very slow rate after about the first 20 days of detention.
Therefore, only small gains in nutrient removal are being achieved by the County requirement.
Figures 1 and 2 illustrate the relationship of detention time to removal efficiency of total
phosphorus and total nitrogen, respectively.
Figure 1. Removal Efficiency of Total Phosphorus in Wet Detention Ponds
as a Function of Detention Time
100
80
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300
400
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Detention Time, td (days)
Figure 2. Removal Efficiency of Total Nitrogen in Wet Detention Ponds
as a Function of Detention Time
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Collier County Watershed Management Plan
3.1.2 Recommendations
A new approach based on the preservation of a site's natural features to minimize pollution loads
and help preserve the natural system is recommended. Such approach should be consistent with
the concept of Low Impact Development (LID). LID aims at minimizing the volume of runoff
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 slowing surface water
runoff and subsequently increasing surface water infiltration into the soils closer to the source of
the discharge, thereby replicating the natural pathways of groundwater infiltration. Further
descriptions of the LID concept are provided in Appendix A.
The application of LID concepts to land development has been assessed herein by detennining
the storm event that generates a runoff volume equal to 0.5 inches. The goal is to remove the
anthropogenic pollutant load associated with this runoff volume. For example, for residential
areas, based on typical lot designs for single-family homes under zoning categories RSF-3
through RSF-6, a typical residential lot has a Directly Connected Impervious Area (DCIA) of
approximately 25 percent. Using the Soil Conservation Service (SCS) curve number (CN)
method and assuming a CN of 74 for the non-DCIA areas, which represents soil type C (slow
infiltration), the design stonn event for LID design should be 1.5 inches of rainfall. For parking
facilities, assuming a 90 percent DCIA, the design event is 0.65 inches. Based on rainfall
statistics for South Florida, the 1.5 and 0.65 inch rainfall events represent the 99th and 60th
percentile. This means that either no runoff will be discharged from residential and parking areas
for 99 and 60 percent of the stonns, respectively, or the pollutant load associated with this
volume is removed.
As stated above, the goal of the new approach should be simply to retain (no discharge) the
pollutant load associated with an additional 0.5 inches of runoff when compared to traditional
designs. As conditions may vary substantially between sites, the LID techniques applied to a
particular development should be left to the discretion of the designer and could be applied at the
lot level or at the subdivision level. Documents that could be adopted by the County as reference
to facilitate design include the "Stormwater Quality Applicant's Handbook" developed by FDEP
as part ofthe draft storm water rule and the Sarasota County, Florida, LID manual. The FDEP
handbook delineates design criteria tor numerous types of BMPs from retention basins and
exfiltration trenches to swales and underground storage and cisterns. The Sarasota County
manual focuses on detention with bio-filtration and pervious pavement.
Collier County staff, the development community, consultants (architects, landscape architects,
and professional engineers), and the public should all be involved in a public awareness and
education campaign to promote the benefits of the proposed approach. The literature on LID
describes LID designs as often more cost effective than the conventional storm water
management design because the size of needed conveyance facilities is substantially reduced,
thus reducing capital and operations and maintenance (O&M) costs. Also, from a developer's
standpoint, the land not used for construction of treatment facilities (i.e. the additional 50 percent
detention pond area) can be turned into home sites. However, it is recognized that, at least
initially, there may be some reluctance by the development community to adopt the new
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concepts. Therefore, various incentives are proposed through changes in the LDC and listed in
Table 1.
An important design feature associated with LID is cluster development. Collier County has
already developed site design standards for cluster development. It is recommended that the
County revisits the road width criteria to consider the average daily traffic (ADT) needs and
make that a part of the cluster development standards. A minimum road width of 18 feet is
recommended for local streets based on an ADT of less than 400 trips, resulting in roads serving
either 36 single family homes or 60 multi-family units. If necessary, parking demand could be
met by driveways or grass shoulders and the County may consider allowing drainage using grass
swales in urban areas.
The off-site parking recommendations should not have negative impacts of safely and would
result in additional availability of land area for new development. It should be recognized that
the current design standards for parking lots were defined several years ago when cars were
generally larger and more difficult to maneuver.
Table 1. LDC Potential Modifications to Treat Runoff for an Additional 50 Percent of State
Requirements
LDe Section Potential Modifications and Incentives
4.02. Building dimension 4.02.01 Dimensional standards for principle uses
Promote cluster development by allowing 18 feet road widths for local streets
standards serving less than 36 single family units or less than 60 multi.family units.
4.05.02 Design standards
4.05. Off-street parking 1. Allow aisle width reduced by 2 feet except for parallel parking
and loading 2. Allow grassed swate dividers along opposing parking spaces. Paved parking space
depth reduced from 18 to 16.5 feet if wheel stop is located 0.5 foot from swale edge
4.06.03 Landscaping requirements for vehicular use areas and rights-of-way
1. Allow use of depressed landscape islands to be used for water retention
4.06. Landscaping 2. Allow rows of parking spaces to contain 20 spaces, instead of 10, between islands
buffering and vegetation if drainage is directed to grassed swale divider
retention 3_ Allow swale divider area to count as part of the off-parking interior vegetated areas
4. Allow parking stalls to be up to 100 ft away (instead of 50 feet) from a tree. Allow
one tree for every 500 square feet (instead of 250 square feet) on interior
landscaped area
6.05. Water management 6.06.01 Stormwater management system requirements
systems and drainage Allow in- -ground percolation type retention systems to achieve water quality
improvement standards retention for residential subdivisions if designed per LID manual requirements
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3.2 Water Quantity
3.2.1 Regulations
Water quantity is also an important component of any stormwater management program because
the reduction in quantity (runoff volume) is the basis for reducing pollutant loads. However,
water quantity also refers to the conditions resulting from large, infrequent, storm events. The
current State ERP requirement has been adopted by the County and requires mitigation for post-
development peak stages for the 25-year/72-hour design storm event. The problem with this
approach is that changes in discharge timing from pre-development conditions may impact other
areas, especially downstream, that are not surrounding proposed new development. This is
aggravated by the fact that, as demonstrated by the computer model simulations conducted as
part ofthis project, inter-basin flow transfers are common in Collier County during large storm
events.
An approach that other Florida municipalities have adopted to alleviate the impacts of high
volume discharges is to limit both peak discharges and volumes to pre-development conditions.
It should be noted that the District has developed maximum allowable discharges for various
South Florida Canals, and the County has established allowable off-site discharges for some
segments of the secondary drainage system (Ordinance 2007-11). However, no current
regulatory requirements limit the discharge of additional runoff volume resulting from the
increased extent of impervious areas.
3.2.2 Recommendations
Updating land development regulations to require that post-development volume mitigation not
exceed pre-development conditions is recommended. This approach, combined with the current
requirement that flood elevations are not exceeded anywhere in the watershed, would ensure that
the three hydrologic factors. water elevations, runoff volume, and timing of discharges, are
maintained from pre-development conditions. To limit the effect that this recommendation would
have on new development it is recommended that the design storm event be the 25-year/24-hour
event (as opposed to the 25-year/72-hour event). More stringent requirements for volume control
using events with a larger duration or longer return period may be considered at a later date.
Preliminary calculations indicate that the additional land necessary to achieve the needed
watershed storage would vary depending on the new development's DCIA. Table 2 lists the
additional land area available for storage as a percent oftotal built area and the actual percent of
total development land for residential developments where at least 60 and 30 percent of the gross
area are devoted to usable open space, per LDC Section 4.02.00. For example, in a development
with 50 percent DCJA, 14.1 percent of the development would be set aside for volume control if
open areas in the development are not considered. However, if the development has 60 percent
open area, then only 5.6 percent of the total area (development + open area) would be set aside
for volume control. Similarly, if the development has 30 percent open area, 9.8 percent of the
area would be set aside for volume control.
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Table 2. Amount of DCIA and Corresponding Percent of Area
Available for Volume Control
Area Necessary for Volume Control
% DCIA of Built Percent of Site with Percent of Site with
Area Percent of Built Area 60% Open Area 30% Open Area
50 14.1 5.6 9.8
40 121 4.8 8.5
30 gg 3.9 6.9
25 8.9 3.6 6.2
20 7.9 3.2 5.5
15 6.7 2.7 4.7
*Bullt Area refers to area developed as single-family residential, not Including open areas
Another water quantity-related recommendation pertains to the policies in County's GMP Public
Facilities Element, Drainage Sub-Element that state that the drainage system should have
adequate stormwater management capacity at the time a development permit is issues. The GMP
also indicates that the system has to be designed "so as to ensure that the final outlet point has
adequate capacity to handle all discharges trom the upstream portion of the watershed under
conditions present at the time of design".
Results of hydraulic analyses conducted as part of this project indicate that various segments of
the primary and secondary drainage systems do not have the capacity to handle large storm
events. In some cases, the canal banks are overtopped even during the 10-year design storm
event. Therefore, it is critical that discharges due to future development are controlled such that
peak water stages are not increased at any point along affected canal systems. It is recommended
that the County require that each development permit be verified using a regional computer
model, such as the Tomasello model developed by the County, for floodplain management
purposes, or a MIKE-SHE model developed using a smaller grid size, e.g. 500 feet. It should be
noted that the application of this recommendation would also require changing the LDC Section
3.07.02 from referencing "surrounding properties" to "any properties upstream or downstream"
of a development.
Another aspect of a storm water management program associated with water quantity is the flood
protection levels of service (FPLOS). The FPLOS is a measure ofthe acceptable flooding depth
along public roads that is considered not to pose a threat to the health and safety of the
community. The more stringent the FPLOS criteria, the more expensive the drainage
improvements needed to meet those criteria. In addition, the larger the drainage system, the
greater the potential impact to the natural environment. Therefore, a balance must be achieved
between risk, cost, and environmental impacts.
Collier County has defined FPLOS criteria based strictly on the 25-year/3-day storm event for all
road types. The FPLOS, as defined in the ordinances, vary from "A" representing no flooding, to
"D" representing substandard service (a detailed discussion of the FPLOS analysis conducted as
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part of this project, and associated recommendations, are provided in a separate technical
memorandum).
4.0 Economic Incentives
4.1 Types of Incentives
The implementation of the LID concept (described in section 3.1.2) should include a number of
incentives. The incentives proposed here relate to changes in the design criteria per the LDC, as
well as the stormwater utilities and the Municipal Services Taxing Unit (MSTU) program.
In terms of the storm water utilities, Collier County Ordinance 2008-80 describes the funding
mechanism and the County's commitment to properly fund the stormwater program. The funds
are proceeds from 0.15 mills ($0.15 per $1,000 of taxable value) of ad valorem tax revenues,
which are deposited into Fund 325. Funding spans through and includes fiscal year 2025.
Although the stormwater utility funds the stormwater program, it is not setup to set up to allow
an incentive program.
4.2 Recommendations
Financing the utility by changing to a fee-based system that in turn is based on the volume of
runoff discharged from each property is recommended. The goal would be to maintain the same
County revenue, but using a different structure.
Similar to other utilities in Florida, a fee could be established based on Equivalent Residential
Units (ERUs) that represent the volume of runoff discharged from a typical home in the County.
The annual fee for each user would depend on the number of ERUs. However, "typical home"
can be defined as a developed parcel with no stormwater controls. Credit should be provided to
parcels, or entire developments that have been design to provide retention of storm water runoff
The advantage of the proposed fee structure is that it can be used to provide incentives for both
new development and retrofit of private property. For example, new developments that are
designed per the LID concepts could use the storm water fee structure to market sales of homes
that pay a lower stormwater utility fee. As indicated above, the fee could also be used to provide
credit to private property when retrofitting programs are implemented. Property owners would
weigh the retrofitting costs with the benefit of a reduced stormwater fee.
A simple ERU fee structure sometimes results in large fees imposed on businesses that include
large parking facilities. Some type of credit system could be applied to the business sector to
reduce the fee impact. However, the credit should be applicable within a defined time frame, i.e.
5 years, to provide further incentive for retrofitting programs. Finally, although the financial
benefit to Collier County may be small, it should be noted that the ERU fee structure allows
collection offunds from federal facilities, which currently do not contribute to the ad valorem tax
revenue.
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MSTUs are another mechanism available to provide incentives for implementing a stormwater
management program. MSTUs are established by ordinance to assess benefiting properties
typically for capital improvement projects such as paving, drainage, and water and sewer
projects. The MSTU programs encourage residents to financially participate in implementing
capital improvement projects. To encourage residents to participate, the County agrees to pay a
portion of a project's costs and assesses the residents for the remaining amount. The resident
participation occurs in the form of annual assessments that would typically last between 5-10
years. Collier County should promote the implementation of storm water management projects
that include LID retrofitting.
5.0 Retrofit of Public Facilities Recommendations
In addition to helping retrofit private property, it is recommended that the County initiates a
program to storm water retrofit public facilities, including the Government Center and the public
school parking facilities. This program not only will benefit the natural systems in the County,
but would be an example of the County's commitment to environmental protection and provide
opportunities for educating the community on storm water issues.
An additional retrofit program that may be considered by the County involves the purchasing of
small parcels in areas where stormwater treatment is limited An area that would significantly
benefit from this approach is Golden Gate Estates where more than 400 streets dead end at a
drainage canal. The program would consist of converting those parcels to local runoff treatment
facilities such as retention ponds or created wetlands. Storm water runoff would be routed to
these facilities prior to discharging into a canal. It is estimated, for example, that a 5-acre lot can
accommodate a 3 to 4-acre retention/detention pond or wetland system that would be able to
treat a drainage area of approximate 50 to 70 acres. In addition to runoff treatment these facilities
can provide better wetland connectivity and improve the local habitat.
6.0 Summary
An important component of the implementation of the Collier County Watershed Management
Plans is the update of the existing regulations that pertain to water quantity and quality and the
implementation ofa sustainable stormwater management plan. The application of new
stormwater management concepts that would help reduce anthropogenic impacts to water
quantity and quality, promote preservation of the natural system, and help reduce development
costs are presented here. Recommendations include modifications to existing permitting
requirements, additional funding mechanisms, public facility retrofits for stormwater treatment,
and private property incentives for stormwater retrofits. Updating the regulatory framework
means updating the County's comprehensive plan, ordinances and land development regulations.
In addition, County staff, the consultant community (architects, landscape architects, and
professional engineers), developers and the public should all be participants in a public
awareness and education campaign to promote the benefits ofthe proposed approach.
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7.0 References
Collier County. 2004. Land Development Code. Naples, Florida
Environmental Research and Design (ERD). 2007. Evaluation of Current Stormwater Design
Criteria within the State of Florida. Orlando, Florida.
Florida Department of Environmental Protection. 20 I 0 Draft. Environmental Resource Permit.
Stormwater Quality Applicant's Handbook.
Gregory, 1. Storm water Infiltration at the Scale of an Individual Residential Lot in North Central
Florida. University of Central Florida. Orlando, Florida.
Metropolitan Washington Council of Governments. 1995. Site Planning for Urban Stream
Protection. Washington D.C.
South Florida Water Management District. 2000. Basis of Review for Environmental Resource
Permit Applications. West Palm Beach, Florida
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Appendix A
The Low Impact Development (LID) Approach
Research has shown the watershed imperviousness has a direct relationship with stream
degradation (MWCG 1995). In addition, as indicated previously, exclusive reliance on
conventional BMPs is not allowing streams to meet water quality standards. Therefore, a new
approach based on the preservation ofa site's natural features has been found to be an effective
way to minimize pollution loads and help preserve the natural system.
LID is a well established approach to stormwater management that relies on hydrology-based
site planning and design. LID aims at minimizing the volume of runoff 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 detaining and infiltrating rainwater close to
the source thereby replicating the natural pathways. LID techniques are often more cost
effective than the conventional stormwater management approach that relies primarily on fast
drainage through storm drains, ditches and/or canals that take runoff to central detention facilities
or to open water bodies.
7.1 Framework
Meeting water quality standards and addressing the water surplus/deficit issues affecting the
natural system requires application of a variety of new tools and approaches that need to be
grounded on a common framework consisting of the following main elements:
Hydrology Centric Site Planning. Site design should consider maintaining the natural site's
hydrology, or helping restore hydrologic conditions if previously impacted. The objective should
be the protection of hydrologically beneficial assets such as soils, native vegetation, wetlands,
and natural drainage patterns. Hydrology centric site planning typically results in better site
layout and reduced development costs.
Water Quality Improvement. The Florida stormwater treatment rule is specifically aimed at
reducing the input of nutrients to receiving waters. Nutrient load reduction is most effectively
attained by both reducing runoff volume and reducing sources of nitrogen and phosphorus. If
stormwater runofftreatment is necessary, controls should be based on appropriate unit processes
for pollution removal, particularly nitrogen and phosphorus, that considers the chemical
characteristics of the pollutants.
Habitat Protection. Runoff reduction and water quality improvement have a direct beneficial
effect on natural habitat. Site development should strive to preserve and/or restore natural
resources on site such as wetlands and native vegetation on site.
Effective Land Use. Collier County is not yet as urbanized as other neighboring counties but
development pressure is mounting. Comprehensive planning at the county level and judicious
site planning at the development level allows effective deployment of new infrastructure,
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Collier County Watershed Management Plan
reduced maintenance needs, enhanced community aesthetics, and access to natural resources for
recreation.
Whole-Life Cost-Effectiveness. The implementation of a storm water management program
should consider the costs of development in terms of both construction and operation and
maintenance (O&M), as well as the potential gains associated with the environmental and social
benefits to the community.
Enhanced Aesthetics: Planning and engineering measures for stormwater control should be
blended into streetscapes and landscapes and become assets to the community.
7.2 Implementation Techniques
LID implementation techniques are divided into three categories: planning, storm water controls,
and pollution prevention. Following is a description of these categories, along with the
techniques that we believe can be implemented in Collier County.
Planning Techniques. At the site level, planning techniques are aimed at taking advantage of
existing assets, especially those that help maintain the hydrology of the site and minimize runoff
volume through maximization of the hydrologic performance. These techniques include:
.
Promote site design based on natural hydrologic patterns by conserving / restoring
such features as drainageways, wetlands, stream corridors, riparian buffers, and
forested areas.
Maximize the extent of pervious areas and areas of absorbent landscape, while
minimizing paved areas.
Disconnect impervious surfaces from conveyance systems so that runoff discharges to
on-site pervious areas.
Manage runoff close to where it is generated by creating micro-controls adjacent to
paved areas
Protect areas of permeable soils.
Design multiple storage systems throughout the site to maximize the assimilative
capacity and create redundancy.
Minimize site disturbance during construction. Research (Gregory, 2004) has shown
that to maintain predevelopment infiltration rates, identified areas within a
subdivision, or specific areas within a lot, should be left undisturbed because even a
small degree of compaction of imported soils has been found to drastically reduce
infiltration capacity,
Protect native vegetation existing on site. Conserve as much as possible of existing
trees and shrubs
.
.
.
.
.
.
.
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. Use native species in landscaping plans and providing sufficient top soil to promote
healthy plant development and minimize chemical application needs as well as
irrigation needs
. Substitute turf with native species consistent with Florida-Friendly Landscaping
guidelines
. Promote cluster development practices with higher densities that reduce road length
and utility footprint.
. Apply road width requirements that are consistent with actual average daily traffic
needs based on the number of homes served.
Stormwater Controls Techniques. From its inception, the application of LID recognized that,
depending on specific site characteristics, a versatile set of controls is needed for effective
stormwater management. These techniques belong to a broad array of engineered features aimed
at mitigating anthropogenic impacts in terms of both water quantity and quality. Key objectives
are to minimize the volume of runoff discharged into the public collection system and design the
stormwater controls in a way that is consistent with the chemical unit processes associated with
the pollutants of interest. Disperse deployment of micro-controls throughout the site is
emphasized, but the storm water management strategy can also include end-of-pipe devices such
as detention basins and constructed wetlands.
The strategy to treat stormwater is summarized below:
a) Runoff segregation. Rain that falls on roofs should not be allowed to come in contact
with fertilizers and other ground-level pollutants.
b) Stormwater controls in series. Stormwater controls should be installed in series to
obtain incremental treatment levels. It should be noted that the upstream- most controls
provide the largest removal, when properly sized. The removal efficiency of additional
controls downstream is much less because the influent concentrations have been reduced.
Stormwater controls in series benefits system redundancy.
c) Bioretention. Roof runoff should be directed to bioretention areas located in the fill pads
devoted to building construction. Pad configuration may have to be slightly modified to
locate the bioretention facilities at sufficient distance from the buildings. The
bioretention facilities should be designed to exfiltrate the water into the surficial aquifer.
Stormwater planters around buildings can also be used to treat roof runoff. The filter
media in the bioretention facilities shall be engineered for nutrient removal. Guidelines
have been provided in the 2008 publication Alternative Stormwater Sorption Mediafor
the Control of Nutrients by Marty Wanielista and Ni-Bing Chang, researchers for the
Stormwater Management Academy ofthe University of Central Florida. From the
findings ofthis publication, it is possible that limestone material from site excavation can
be used as a component of the engineered media.
d) Filter strips. As implementation of imperviousness disconnection, filter strips should be
added to receive runoff from paved areas and discharge it to bioretention facilities,
vegetated swales, or other stormwater controls.
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Collier County Watershed Management Plan
e) Surface depression. Design absorbent landscape areas as depressions that temporarily
store stormwater and allow it to infiltrate. The drainage properties of these areas should
be designed so that they infiltrate the water without becoming a nuisance.
f) Permeable pavement. Permeable asphalt or concrete should be used in parking lots as
much as possible. In combination with conventional pavement for high traffic surfaces,
permeable pavement is an effective way to retain runoff. The gravel reservoir below the
pavement stores the water and exfiltrates it through the bottom. If drainage through the
bottom is limited by the fill material, perforated pipes can be used to drain the reservoir.
Several studies of permeable pavement systems are available on the University of Central
Florida (UCF) Stormwater Management Academy's website http://stormwater.ucf.edu.
g) Conveyance in vegetated swales. Provide vegetated swales between building pads and
along streets and driveways. The swales should use the engineered filter media described
above. Check dams should be used to enhance infiltration.
h) Pocket wetlands. Distribute pocket wetlands through the site, in series with other
stormwater controls, to receive up to 10 acres of areas drained by swales. Pocket
wetlands can also receive drainage from pervious pavement to restore the storage in the
gravel bed.
i) Central treatment facility. Performance of conventional stormwater treatment
facilities such as detention ponds can be enhanced with littoral shelves; settling basins or
phyto-zones; wetland areas, especially upstream of outfalls; and internal berms to
lengthen the flow path. Floating wetlands can also be deployed. These central facilities
need to be stocked with fish to control mosquitoes.
j) Stormwater harvesting. Runoff stored in a detention facility can be used as a source of
irrigation water. In addition to reductions of pollutant loads to surface waters, stormwater
harvesting can reduce potable water use.
Other LID stormwater controls can be applied depending on the nature of the site and can lead to
innovative solutions. The following are examples ofthese other alternatives:
. Vegetated roofs absorb rainwater and the excess can be directed to storm water
planters or bioretention facilities as described above. Vegetated roofs provide
additional benefits in roof membrane longevity and cooling energy savings. These
systems are most commonly deployed in large buildings with flat roofs.
. Rain barrels and cisterns can be used to collect runoff hom conventional roofs. The
water could be used later for irrigation but ifnot used, it must be drained from the
cisterns to provide storage for the next rain event.
Pollution Prevention Techniques. These techniques are aimed at minimizing pollutant loads
and include the following:
.
Enforce fertilizer management ordinances
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.
Designate elements of landscaping (e.g., vegetated swales, bioretention facilities, and
surface depressions planted with absorbent landscape ) as storm water management
devices where no chemicals shall be applied
Educate homeowners about impacts on water quality of excessive chemical
applications. A tool available for this purpose is the Florida Yards and Neighborhood
handbook.
.
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