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Item 8AAGENDA ITEM #8A FEBRUARY 27, 2006 CITY OF ATLANTIC BEACH CITY COMMISSION MEETING STAFF REPORT AGENDA ITEM: Follow-up to City Commission action denying a request for a Waiver from Section 24-66 of the Land Development Regulations requiring ~• On-Site Retention for a lot located at 1718 Selva Marina Drive. SUBMITTED BY: Rick Carper, P.E., Public Works Director-~- •~ Sonya Doerr, AICP, Community Development Director DATE: January 28, 2006 BACKGROUND: On November 28, 2005, the Commission took action to deny a request for a Waiver from the Land Development Regulations related Section 24-66(b), which requires on-site storage of stormwater runoff such that there is no increase in the rate or volume of flow to off-site, for a property at 1718 Selva Marina Drive. Because of Staff error, the owner, Mr. Fitzgerald, was not notified in advance that his request had been scheduled for consideration by the Commission. When contacted about the waiver denial, Mr. Fitzgerald stated he had not intended to go forward with the waiver request at that time. Mr. Fitzgerald, has now submitted a written waiver request for the purpose of being heard by the Commission. (See attached chronology.) Since it's passage, LDR Section 24-66(b) has been interpreted as applying to single-family development because the St. Johns River Water Management District regulates multi-family development and applicants with WMD permitted collection/treatment systems are ~. specifically exempted from this requirement. RECOMMENDATION: As previously provided, Staff continues to recommend disapproval of the waiver request. LDR Section 24-66(b) gives the Director of Public Works authority to waive on-site retention "if storage is determined to be unnecessary or unattainable". In this case, Staff feels it is both necessary and attainable, and that to grant the waiver would set a dangerous precedent for the City. ATTACHMENTS: Chronology of requested Waiver and supporting information from November 14th and 28th City Commission meetings. BUDGET: No budget issues. ~, REVIEWED BY CITY MA AGER: February 27, 2006 regular meeting AGENDA ITEM #SA FEBRUARY 27, 2006 CITY OF ATLANTIC BEACH CITY COMMISSION MEETING STAFF REPORT AGENDA ITEM: Follow-up to Gity Commission action denying a request for a Waiver from Section 24-66 of the Land Development Regulations requiring On-Site Retention for a lot located at 1718 Selva Marina Drive. SUBMITTED BY: Rick Carper, P.E., Public Works Director Sonya Doerr, AICP, Community Development Director DATE: December 30, 2005 BACKGROUND: On November 28, 2005, the Commission took action to deny a request for a Waiver from the Land Development Regulations related ~' Section 24-66(b), which requires on-site storage of stormwater runoff such that there is no increase in the rate or volume of flow to off-site, for a property at 1718 Selva Marina Drive. Since that action, the property owner, Joseph Fitzgerald, has advised Staff that it was not his intention to go forward with the waiver request at that time and stated that he had not been notified that the request had been scheduled for consideration by the Commission. Mr. Fitzgerald, however, had been in discussions with both Planning and Public Works Staff regarding available Commission agenda dates and had submitted a written waiver request in Octoberforthe purpose of being heard by the Commission. (See attached chronology.) While Staffs recommendation related to this matter remains unchanged, Mr. Fitzgerald, upon written request to the City, may submit a new or amended, waiver request if he chooses to do so. Unlike Rezonings, Zoning Variances and Use-by-Exceptions, there is no 365'-day time limit to re-apply following a denial. RECOMMENDATION: As previously provided, Staff continues to recommend disapproval of the waiver request. LDR Section 24-66(b) gives the Director of Public Works authority to waive on-site retention "if storage is determined to be unnecessary or unattainable". In this case, Staff feels it is both necessary and attainable, and that to grant the waiver would set a dangerous precedent for the City. ATTACHMENTS: Chronology of requested Waiver and supporting information from November 14th and 28th City Commission meetings. ~°' BUDGET: No budget issues. REVIEWED BY CITY MANAGER: ~. January 09, 2006 regular meeting AGENDA ITEM #8A FEBRUARY 27, 2006 x.. Chronology - 1718 Selva Marina Drive -Public Works Department (All dates 2005) May 5 -Plans received by Building Department. May 10 -Routed to Public Works. (AS400) *^ May 12 -Public Works comments with example On-site Retention calculation form faxed to Gamel Construction. Discussed comments with Mr. Gamel by phone. May 16 to May 27 -Met several times with Frank Gamel to discuss various options for retention. May 27 -Approved Gamel proposal for on-site retention. Excluded rear half of property from calculations because it drains directly to Selva lagoon. May 31 -Building Permit issued. (AS400) October 05 -Initial discussions about waiver request with Sonya. October 26 -Began drafting staff report recommending disapproval of waiver request.; discovered City copy of drainage plan /retention calculations missing. October 28 -Visited construction site - no copy of plan available on site. October 31 -Phone conversation with Frank Gamef -Discussed that Mr. ~, Fitzgerald was requesting waiver, was not aware of that. He does not have copy of approved plan. November 7 -Staff report submitted to City Manager. November 14-Initial Commission consideration of request. Not acted upon because staff not sure applicant contacted. November 28 -Commission denied waiver request after staff reported a letter had been sent to applicant (sent to wrong address). December 14 -met with Mr. Fitzgerald and Frank Gamel to discuss On-Site ~. Retention requirement. Copies of Staff Report and Commission minutes provided to Mr. Fitzgerald. (Appointment was for 3pm, showed up at 1:10; I let him know meeting would be abbreviated due to weekly meeting with City Manager). +~• AGENDA ITEM #8A FEBRUARY 27, 2006 Nc~vemlaer3'&. 2(}(1~ REGUL.3It COMI-I:I~SIt}N 1iE1:TrNG F~~e 1~ NZotion: a,pnoi»t. Cara~le Varney to fill the vacancy on the Tree Conservation. Board. Alhved by ~Volfs€~r~, seconded l~~r Simmons Commissioner Waters asked that the applications be include-din the a~e~~da packets when a~tior, is sei~edutcd tc he talon. Vote: ~"' Aye: S - Born4, Fletcher, Simtnnns,'~Vaters, Wolfson. Nay: 4 11~IC}TI4N C 1RRI~D .action on. Resolutions 6. .Action on Resolutions None. tletion on Ordinances 7. Action on (Jrclinances hTa»e. Miscellaneous Business S. Miscellaneous Business A. ltetluest to replat a portion of BIoek 1 tivthin 1Jnt 1 of the Selva lFlarina subdr~~ision, including all of Lot 33 and poxtions of Lot 3'2 and .Lot 3~# for the purpose of creating three single-famuly residential lots ran.gxng in size fxoxn 31f`7 square feet Lo 12,38 square feet in L,at Area. Tlxis .property is located at the north rest earner of 12th Strut and Selva Maz~z~a C%rele (+City 141anaaer) -This item was acted on earlier inthe meeting. W ~ B. Request for a ~~'aiver froth Land I3evelUp!txtent..Regulator~ 0 Requirement for On-Site Retention for a lot located at 1:713 Z Selva 1vIarina Drive .(City l~Ix.na;er} City Iwianaber Hanson npted that this item «~as addressed at tl~e pi-eyious Cornmsson meetin.~ and that the: staff report vas included in the a~end.a ' packet along with `vlr. Carper s recc~tnrneneatir~n for. dertia) of r1~e request. Rick Casper., Director of Public Works,. added that st;~ff did: »~ot receive an}~ response from the. applicant. rrlntion: Deny it3e xeguest for a ~vaivee from. Land De~~elonnrtent ~" Re~ulatnns reauirententl'or on site retei;tion for a Iot located st 17'18 Selva l~tat~ina Drive. - - ----•-••• • ••-- •- ... AGENDA ITEM #SA FEBRUARY 27, 2006 1\~o~•emhec 2$. 2005 RRGt?[_AR fi'fl'lfhitSS[n.M1' i~9EET'ING Page 1S ~„ Commissioner eaters painted nut st:zff s error in Choir calculations pertaining to the owner's application and the need to treat all properties uniformly in respect to stot7nwater 1°etention requir~e~nents. ~1<o~ved by Sirttmans, seconied bS~ Bvrno S'otes: ~}•e: 5 - l3orno, l~'letcher~ S1IilIIlOI1S~ 't'~~aterS, '44'alfson 1\ra} . Q LVi()TIfO~~ti. CARRIED C. Regaest far a'4'Vaiver from the I,al~d. Development Regulations to exceed the ~U9r Imperious Surface Area,irnit within the ~'" Selva Lin. kside PUD for a lot tacated at 1538 L'Inl:side Drwt, 1Vorth (City Manager) "" Y'4•Iotiar-: Approve therepuestfor a ~vac~er to the 5090 Intr~ervous Surface Area limit, alla~vin~ for a rnaxirl~um ISA of ~~9c for the Iot Iacatedat 138 I.~inlsidc Drive. 1~rloved b;y Simluons, seconded bar Borne ~* Commissioller ~'~aters disagreed with st~rirnming pools being considered as a penfocis surface aril indicated that this wars contrary to the perspectiw~e of .the Saint: 3ohna Rive: Water ~~lanagernent District. Ike believed..that ~~~ater. ~. from. this prapexty tivill curl into another person`s ~~ard ar into tl~e street and:. stated that he waezld pat apprflve this request. ~,,, Charles Labassi, 15'38. Linkside Drive, intt~adueed himself as the applicant. and: acknowledged that he exceeded. the im~err~iaus surface area limit. He pI-ovded some background infrarmation an his neigt~barhood and his ,~, inYolvement in the Linkside Homeowner's Assaciatian. He discussed the .results and effects of the stormwater runafC from his property. Rick Carver, Director of Publc'UVorks, displayed tt pliato of the lot and the Camrrrissioners discussed the pelmeabilt}' andsurface area of the applicant's deck, swimming pool, and pavers on the propert}~• and their effect. on surraundin~, areas. lvlayar ~'~~alfsan commented that Atlantic Beach leas a eery Iertient. impervious surface area requirement compared with that of other cities and: ~' spoke against granting the waiver. Tl~e question tivas called anal a roll call ~••ate was taken Tay City Clerk Bussey. ~• AGENDA ITEM #4E AGENDA ITEM #SA FEBRUARY 27, 2006 +CITY fll~ ATLANTIC BE,ACN CITY GC?MM1SSlC~N Nil: lrt[f~lG ST~4FF REPQRT ~„ AGEh(Ri4 ITEM: Request for a Waiver from Land Development Regulations Requirement for On- Site Retention far a lot located at 'E718 Seiva Nfarina drive SUBMlTTEQ SY: Rick Harper, P.E., PuUlic Works Director DATE:. October 26, 2405 BACKGF~OtJNC3: Land. Development Regulations (LDR} Section24-66{b) regares o~•~ site storage of stormwater runoff "such that there is nQ increase in the rate or volume of flow to off-site,. from evert+ developed Qr redevelor~ed Parcel" temphasis added). The property owner 'ss requesting a waiverfram vn-site re#entic-n requirerrtents by saying the LDR should not: be applied to a new home within an already existing subdivision, stating the regulation "applies only to subdivisions and Matto individual lotsa. As Hated, Section 24-6fi(~) specifically applies to both development and redevelopment at the Parcel flat) level. Although the Selva Marina Subdivision is nearly built out, the lot in question was undeveloped at the time of the permi# re~ques>.. The intent of LDR .Section. 24-6C(bj is to ensure thy; capacity of existing stomrwater collection systems is not exceeded :because of the increase in stormwater runoff caused by the increased impervious areas resulting from Moth development knew construction) and from redevelopment (tear downs). That the property is being built to less than 50% impeNiouS simply means 'it is cornplyirg with another section of the Gty's L[.7R (Section 24-'f04 ~fj), unrelated to on-sate retention. Public Works approved the Building permit request for property at 17'!8 Selva Marina Drive on May 27,_2QQ~5. Atthattime, Public Works had conducted several plan reviews with the Builder (G!amel Con-strucoon} to obtain a plan far can-site: retention that met the spirit of the Cit~r's Land l~evelapment Regulations. Because the lot has natural Type B drainage {splits front and rear), Staff agreed that the portion of the lot draining directly to the lagoon would Hat be considered in the retention calculations. The front half of the lot drains to Selva Marina Drive, with an existing City catch basin at the curb. This curb inlet is piped directly to Selva Lagoon along Mr. Fitzger~ld's northern property tine. Combined with flawfrom the inlets immediately across Selva Marine Drive,. this 18" pipe carries runoff from approximately 7't}(~ linear feet of Selva Marina Drive, over 90fl '"" AGENDA ITEM #SA FEBRUARY 27, 2006 ~GENb,~ ITEh~I LSD a~. NDVEI1~BE~ 14, 2005 fleet of Live Oak Lane and 5Q0 feet of the north side of Palmwood Drive and all the properties adjacent to these rows.. Asa .result of an Administrative oversight, Staff 'ts unable to find .the permitted drainage plan and approved on-site retention calcuia#ians for this properiry. Staff requested a copy from the wilder who stated he did not have tfiem eitfi+er. However, tfie portion of the tot draining directly tc~ the lagoon was taken into account when the amount of on- site storage rertuired was calculated. ~" REC014AMENaAT10N: .Staff recommends disapproval of the waiver request. LpR Section 246fi(b}gives the Director of Public Wanks authority #ra waive on-site retention "`if storage is determined too ~be unnecessary ar unatkainabEe°. lr~ this case, Staff feels it is both necessary and attainable, and that to grant the waiver would set a dangerous precedent fair tfie City. ~-TTA~I'HMIENTS: 1 }Waiver Request from Joseph Fitzgerald, 1718 Selva Marina Drive *~ 2) CQA~e Land Development Regulations, Section 24-66 ~) Required retention volume calculation worksheet 4) Site Plan -1718 Seiva I'~arina Drive BUQ~ET No budget issues.. ~,. REVIEWED E3Y CiT~I MANAG "' ,.--_.-_.-..._ ,_._ ._ .____.- AGENDA ITEM #8A , - - . - - - --........ _ .. _-. _ _. _ ._ FEBRUARY 27, 2006 ~. AGEI4AA ITEvI #8C3 ?~'0~'EIVI.$IRI~, 200 City of Atlantic Beads City Canimssioa; h~Ieetng Agenda Item: Request far a ~y~ai~°er for ny property- (171ki Sel~'.1 Itilarina Dr.) regarding Regulation _ ,Atlantic 13eacl~ Zoning, Subdivision. and. Land De~•eloptrtent Rebulations, Section 24-Gfi`b). Present Situation: Upon appl;~in~* for a l~uildna permit for, my rt~ew hoane,lvlr. Ri;cl. ~"" Carper, P,E. PubIic'4'~~orks D:irectar usad section '~4-G6(b} of the at~oae reguta.tion to calculate the volume ol'run off and storage requirements far my india~iaual lot at 171 Selva ~4arina Dr. The results from tl~e calculation. required 3,7~~ cu. ft. of storage,. After ~`" discussion ~•ith m}' builder, 1WI,r. Fra~~k Gamel, Mr. Carper reclueeci the requirement to ?,~QO cu.1't: l3etr~x~een the house at3d the road (see attached sheet ;~}. Upon. additional. discussion with 1Vlr.. Cramel, he agreed, to a 6" brm to lye consttl~ctecl in the frornt of the property t:o retain. the. water. Then the building pErmit ~~~as app:ro~fed. 'V~~aiver:Request: I request.that the Regulation of Atlantic Beach, Subdi~'ision and Land Dcv~loperkent, Section 2~-66{b) ~aot be applied to n~}P property an 171 S SelEfa Marina 17r. Reasons: T do ~1ot believe that. an individual lat, within an t~stablislied community should be required t~ comply with a re~ulationthat has as its intent to cover a Suladi~~•ision and Land Development situation. Selva tilarna ~~as de~reloped i.tt tt~e 19~0's ,~„ and constntcted the water management system. for the subdivision fc~r all the homes at that dine. Tf-:the present l'hinkita.g of the requirement for a 25 year and 2~ Hour r:ti.nfall (9:3 .nc}tes) had changed since then, appl}+ng this regulation. to the t~~to rernainina praperties on the. street, ~xfhich do not ha~~~e hones on. Them, {;2 homes out of ~~ - 5~'c) 4~~ould hay°c a small impact on the 4vat~er macagement situation. certainly, ttlere ~~ould not be enough iiupact to correct the situation if the system is no~~+ defined to be unable to hattdlc tfie S1tUc1ti0i1 1.t1'it5 13reSetit COlldl~lot3. I don't belicwe the reguaticn is berg applied to homes w~l~ich are being rebuilt ar under going rena~=atiotls. ~"' Reasataiz~g fine last 40 feet of my property is located in the canal ~whicli is used as the «tater management s}~~stern for the. subdi~~ision. Thereft~reT 16 ~c of the total property is bein4 used for the system presentl}°. (1SQ 1"t. ~ 2~0 ft. = 37SQ(1 sq. fl, ~ ~01't. "`" X I5t) ft..- 600 sq. ft:~ Also, on the North East corner of the iot., -which is iii tl~e street, there is a storm water drain c~~hich collects the. tix~ater in to a hurie<l 3 ft, comi~~~ted steel pipe draiii~3g under the property into the canal in the rear o1'the hon~e.1_feel that I am already contributing to the water manaaernent of'the co~x~munity. Reasoning {pant,} 'I'le front of the prc~pert}~ {,home to property litre is 7~ ft X i50 ft.} is 11,250 sq. ft. If the. initial calculation of a storyge requi.rernent (~,7~0 cu, ft.} tivere to ~+• a~w AGENDA ITEM #8A IE FEBRUARY 27, 2006 6 AGEt~tDA 1'L'~!~•i tau NQVEMI3E12 24, 2t}US ~"" ~ apply algid the depth. were ~/x ft. then. tt~.~o thirds of the front yard v~~oulti b~ a t~odn~ pond. Also, I followed the regulation. regarding the tree retel~tion regulations and to follow this «<ater.retentidn approach the trees in the holding pond area ~~~ould be affected neg~~tive.l}?. Sununar4~; T'ttc e:Kistng restllaxion, (sectiolt ~4-6b h) applies only to subd%~risc}ns and not to individual lots. ~"" f~tir building plans and specs do not in any way violate the impertFious surface area limit of 70~o which ryas established in ITT©~Fember of 2001, Jn addition, the last 40-feet. of our lot is in the canal, part: of the existing storm water management system. Tltel'efore ~+re aireacT~f have a storm. eater rnanagclnent system OIT our lot. The fact that. I~~Ir. Carper reduced. tl~e requii°ement indicates that-he also believes that: the restlltiltg calculation is too much for an indis~idual lot, Mr. Frank Gal~Iel, zrly construction manager, allc an active bua.lder 'for the last. 2S )rears at the beaches, has also indicated that he has never seen this kind of ~„ anproac:h to an individual lot. Secti:an ~4-~G(ci) permits the corrlmission to authorize limited waivers on a case by case. basis, from specillc provisions of the land development ~„ t~gulativns tivhen it is demonstrated that colnplial~ce with such proti~sion would be unreasonable, in confirt with tI7e public. il~terest, or a practical impossibility. Regards, Joseph Fitzgerald 0 ~. AGENDA ITEM #8A FEBRUARY 27, 2006 a. ,,,`;~. ~. r ~ ;, ~~ rn (M $~ ~. ~ z ~. ~elv~ Niarinc~ Drive ~~ _ ~.~..._, _ o _. ~ ~, ~~ ~; n~tia'. s+ts40 ,/~ f.'LkVE T-tC?~$Y pe I 1F1TtGEr21~LDLR~SIC7 1r1Y~t,~,1 ~~ ~ ~ F+FR~[iittlAT M ,L^F Fdi 4~tlWJe: M. ~C~PLIA -"• 1 ~ 5e#a~: S.~i' . I'-C" Aacd-ulmNiy ,~.•_ L(7t ~~. S~GG~ J - ~~I~dG 1 5C7~~nC~ U~•I~~. ~ ~ C1CF.'YTCR kL~P.^Mi=.E FC'R /ts ~t~fMC~F. ~ ~~. ry~ zV'SUkES. R!~C 6!EL+sGctA~M. vE+n.r 47: A1:X' 10 I,. .,~. I.-I II 51u.. MCR='ii @,. y~p~c II ... FZGCI+~IYI.IAI riiL`BaG,pi v ~ ~/!. ~~At1'YIC g88G~'S. GI61'~~e3 I =cwv'a~vww. w ocexv~wcmwau,~st •C9..FML. l ~: ~a soµsnuncw. lllli AGENDA ITEM #8A AGENDA ITEM #4E FEBRUARY 27, 2006 JANUARY 9, 2006 AGENDA ITEi~•f #SD n CI t~'EI~~II3ER 1~, ?tltla ~. ws AGENDA ITEM #8A FEBRUARY 27, 2006 ~~ '~- ~ ~~ ,~• ~. , d 'L 0 c 'L C a~ N ti - W s ~ ~~ ~ ~ ~ ~ ._ .~, o ~~a~ c~ ~ U ~ tCi ~- ~ Q ~ ~ ~. ~ v ~ ~ Q o ._ ~ 4) p ~ ~ ~ ~ .- > ~ •• O ~ .- ~ ~ 4~ ~ L ~ ~ ~ o -~'-~ s ~~~ ~o~ ._ ~~ ~ ~ ~ ~ ~ ~ v 0 ~ ~ ~ ~ a~ ~'~ ~.. ~~ 0 0 3~ 0 o, as ~~~ _~, O' L ~1~+ L L Q 0 L 0 0 o .o ~. -~--~ C~ ~- U CCS -' c~ U 4~ ~ V ~ ~ ~ c~ a to ~ ~ O ~ -- -~-+ o -~ _ ~ a~ a~ > ~ ~ ~ ~ U ~ O L ~ AGENDA ITEM #8A FEBRUARY 27, 2006 a~ U c~ ._ O V CCS -~ Cn 0 a~ ~. ~• AGENDA ITEM #8A FEBRUARY 27, 2006 ~.GENDt1 IT I_:~5 #SD Tr'E31'B1~1BER 1~. 3()0 Sec. 24-66. Stvarm~water, I?raurage, Storage and Treatmeaat ~.equireuaents, (Emphasis added) ~"" (a} Topography and Grading. lA.ll Lots and Deveiopznent sites shall be constructed and graded in such a mazufer so that the stormy"ater drains to the adjacent Streets an existing. natural element used to convey storm~vater {See section 2?-30a, definitions: ~"" Stormwatcr l4iartagement Systetxt}, or a Cihx drainage structure after rriceting on-site storage roquzrcments, as listed t~"Rhin this SeGtlon. 1~e Cry shall be pro~rided ~~"ith a pre-construction topographical survey prior to the issuance of a Development Fertnit and apost-cc~r~struction, topagraphicai survey prior to the issuance of a certificate of Qccupancy. Said surtiyey"s shall be prepared by a licensed Florida sunYeyor, and the requirement for either. ar bflth surveys inay be u'az"ed 13y thee. Director of Public ~. Forks if determined to be unnecessary. {b) nn-Site Storage: The Applicant shall be required to pro~7de on-site storage, su4h that there is no increase in the rate or ~•alurtic pf fln~r" to off site. from e~erv developed or redeveloped P'arc~el, and. pro~~ide docurnentarions and calculations to demonstrate-compliance. Development Projects pre~yiouslSy permitted by the St. Johns River eater Management District (SJR~4'Ml~)s ~~~hich have an in-compliance retention or .detention system that collects and controls run-off are exempt. The requirement .for on-site storage may be waived icy the Director of Public Wcirks if storage is determined to be unnecessar}r or unattainable. Volume calculations for Lots that require on-site storage should. be based on the difference in run-~fI'volume generated. by the ne~v impervious area ~"delta irolume") and would be calculated by: ~'=CARf I2, where V =volume of storage in cubic Feet, A = area of the lot in square £eets R = ~~ year anal 24 hour rainfall depth (9.3 inches) over the lot.. area, and G = nxn-ofl" coefficient, which is 0.6 for the ~~°~''o .maximum imperr"iousness, 0.4 .for 2~°fa imperviousness, and 0~2 for 0°~'o iirper~}iousness. 'This delta volume (post Sr minus pre ~' in cubic feet) must be stored at least 1 foot abo;de the wet season water table and below the overflow point to off site (in many cases this.. may be the adjacent road elevation). As ax-- optiai~, and as approved b3' the Director of Public WForkss tl~e owner of the parcel to be developed or redeveloped may implements. at the applicant's cost,.. off-site storage and necessary conveyance to control existinb flood stages off-site. (c) Flood Plain Storage:. There shall. be nc~ net loss of storage far are ;s in the i 0{i-year #loadplairi, where a floodpiain elevation has been defined by either the Federal '""' Emergency Management Agency {FEMA) on Flood Insurance Rate Maps (FIRIvIs), the 1995 Storzxir~vater Master Plans the Corc City project, ar the ?00~ Ston~~water Master Plan Update (e.g., Hopkins Crook). Site grading shall create storage on-site to .. mitigate for filling of volume on-site. This storage is in addition. to the storage rEquired fr~r the increase in anperc~ous Surface Area. ~. ~. AGENDA ITEM #8A FEBRUARY 27, 2006 AGENll~, ITEhI ~s Iti©VE1YI'l3ER 1~, 3dttS (d) Storm~vater Treatment: StormK~ater treatment shall be pro~~ided for a volume equivalent to either retention or detention ~irith filtration, of the run-off from-the first one. (l) inch of rainfall; or as an option, for facilities with a drainage area of less than one hundred {l (ltj) acres, .the first one-half (l,.'?) inch. of run-©ff pursuant to Chapter C?-2~, Florida t3.dminstrative Code (F",A,Cj. ?~1a discharge from an}' starmwater facility shall cause or contribute to a tilolation of eater duality standards as pm~~7ded in Scotian 6?.302 of the Florida. Administrative Code. This treatment volume can. be included as part of the on-site storage requirement in item d (2) of this Section. te) NPDES Requirern.ents: All. construction. activities shall be in confarna.ance with the City's 1\~atioraal Pollutant Discharge Elimination S}{stems (NP`DES) perzrrzt, in ~. addti:on to the requirements of the V4'ater Management .District. and the Florida Department of Environmental .Protection. Nl'L31/S requirements include. use of Best I~!lanagemcnt l'raetices (BMPs} prior to discharge into natural or -artificial drainage ~„ systems.. Beginning ?!vlay 1, 20~w, all construction projects of one acre ar more ~c~iil require a ItiTPDES: permit. (f) Enforcement: Subsequent to approval of a .property owner's final grading, uicluding on-site and/or flood .plain. storage. and storm~v titer ticatrnent, the irnpro~ements :shall be maintained' by the property owner. Failure to maintain. the mproi~ements rxTill require restoration upon notification b}~ the Director of Public ~'i'orks, S~~ithin a stipulated time frazz~e. If restoration is not timely completed., the City shall have the right. to complete the restoration, and the City's actual coast incurred, together with a charge of 10(}°: ~ of said costs to cover ~e Cit<f's administrative expenses, shall be charged to the o«er. AGENDA ITEM #8A "' ' " ' ' ~'~' " '_"'"" ""°' FEBRUARY 27, 2006 AGEIv~A IT>~~i #RJj ~'" I'~4~~r~1t~iBER I~, 2taE?~ Ru~nafi'Volume Caculatians (Ref Cite a~ Atlantic Beach Zanin;, Subdi~•is-.ion an:d Land Devclap><xnea~t Regulations, 5ectiau ~~-66(b): 17Y8 Selv~ Marina Drive Volume calculation. for lots that require an-site storage shaald be bsscd on the difference itt tuu- offvolume gezzrezaced b} the ner~• imper4~iaus area ("delta valuzne") aid ~~could ire calc~slated bar: ~7=CAR+ 1 Z. \4~here tr = valumc of storage in cubic feet, ~„ A = src:a of the lot in square feet, R = ~5 year and,29 hoursainfall -depth (9,3 inehrs) over the lot.. area, and C =run-off coefFicient, which is 4.6 far the SQ°lo maeimum impen~ious coverage, 4.4 for 5°-0 impen~ious cvvera~e, and 0.2 fvr Q°/`o icnpervivus car~t:rage. ' This delta ~rolurne (past ~T minus pre V in etrbic feet) must: b~e stoned at least i foot aba~~e the v~Ct ~'" season water table and below the vv~flow point to off-site {in tnauy oases this may be the adJacertt road elevation). ,As art opiion, and as ~ppri+ved by the l~irc>ctor of Public forks, the awtier of the parcel to he develvpeci orzedeveloped tray ianplementT at the applicant's cast. off-site storage and necessar}~ COnVeylrtCe to Control el't5tttl~ flood 5kagcs off sttc. Caicu[ation; ill total lot size due to type Bdrainage- 3£9S9f'2 - 17r9'?9 fi a.. Pr evel~~ient:, Runoff'~oltxttie = Q:2 {no iznper+.~ious surface} * 17'429 ft~ *9.3 in.112in.lfl Zt = ~7aa t't~ Past level meat: Runoff Volume = Q.6 (5q°~u inlpcn~ous surface) * 17,429 ft~' *4.3 n.112ut./ft V=S1U2ft~ l?eltg '~relume = $1(l2 fi# - 270Q ft~ ~° 5~ti12 €t3 (This is the volume-af storage that must be provided for this tat, Cither on the building site, ar with Public VJQrks atyproval; afFsfte). Required Dacttmer-t~tion: Include a black or section. an the Pati~ing and D!raiua~e Plan. shaving the regUremcnt and amount of storage prr~~dcd. (See example below) Stotm«~ater Stora a Re uirements Area Percent Im : cn•iaus Runoff Volumc Predevela meat F't Ft' PosrDevelo meat Ft' Ft' I Stot•a a Volume Re ttiretL: _ F[ ~Stora a Volttmc Protzded: Ft' , 1