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Home My WebLink About1999 Replacement of Elkcam Dam WCSFebruary 25, 1999 CERTIFIED NC.Z 397 082 955 Earl Masteller, P.E. Masteller & Moler, Inc. 2205 14th Ave. Vero Beach, FL 32960 RE' Replacement of Elkcam Waterway Control Structure Application No.4-061-0082AGMF-ERP Dear Mr. Masteller. The St. Johns River Water Management District is in receipt of your Individual Environmental Resource Permit application. Upon preliminary review of the proposed project, the following technical information is required to sufficiently review the possible impacts the project may have on the surrounding area. This information is being requested pursuant to the authority vested in the St. Johns River Water Management District under subsection 373.413(2), Florida Statutes, and sections 40C-4.101 and 40C-4.301, Florida Administrative Code. In order to expedite the review of your application, please use the application number referenced above on all correspondence, and submit three (3) copies of all requested information unless otherwise indicated by a specific information request. 1. The required application fee is $3000.00. 'IC cFeck 1df'$500100 Was received. ,P.lease'submjt{a gheck-foc;, 2;500.Q0,0.!; 4 2. 1 would like to clarify an Inaccuracy in my September 29, 1998 memo to you regarding the Craven Thompson ICPR flood model for the City of Sebastian. The Craven Thompson model included a cross-section of the control structure located within the Elkcam Waterway. Flow rates over the control structure in the model were calculated based on this cross-section. At the time I reviewed the model, as -built plans for the control structure were not available and I thought that the control structure cross-section included in the model was representative of the existing control structure. After review of the as -built plansof the.. control structure, which you submitted.with this application, I have determined that the cross-section in the model is representative of the previously designed control structure which was permitted by the District back in 1988. Fare ar from the submitted as -built elevations of the existing control re and the flows calculated in the Craven Thompson modal, Illnt I, g structure is not capable of handling larger storm event flows n1111 ause upstream flooding or fail in a large storm event. Requlr111q �N the new structure based on the peak discharges over the a><Isry11U 11 to Fro structure would not be appropriate. Your permit application e1111111 asis the new control structure design on mimicking flows olid Klq tttnl, e 1988 design, is appropriate. Please note however, that the k — k discharge ates to ze in ur design are chapriate r es which were rcalculatedlutiliz no the 1988 designte o the, yH structure. These discharge rates are listed at the top f my �pq�tF1 ` ollows; 713 cfs for the 100 -year storm event, 577 ofs for the 20 jtr +111d vent, and 446 cfs far the 10 -year storm event My Inclusion of tllp t• _ Pipes nfus on this existing may have caused.re in the model was in error and I apoloplzq Iq�11„•ey 3. The submitted computations of peak discharges over the proposed oo structure do not account for tailwater conditions. The Craven ThomPsrlq ltllVl l model, which is the basis for the control structure design, utillzee a pat ,4 24-hour taiiwater elevation of 15.6 ft. at hour 21.0. The peek telltvrylp�h_ elevation is almost three feet above the invert of the two proposed gglee t Please account for tailwater conditions in your control structure deslpll 4. Please provide an operating schedule for the proposed gates and Joehow st IItN and base flows andation of s peak dischagates will rges es tth out peak ch the structure .es upstream of the etrhnlltlM P 9 9 �. 5. Please provide an explanation of why the normal water elevation In the t, system is being raised from elevation 12.0 ft. NGVD to 12.67 ft. NGVp "llnl Demonstrate that raising the normal water elevation will not adversely ry11M . the water quality tf discharges over the control structure and flood upstream of the etaUwNt.l If the applicant desires to dispute the necessity for any information in,ll lir„1„ an application form or in a letter requesting additional information, pursunnl 1,,II I'n, 40C-1.605(5), F.A.C., he or she may request an administrative hearing in m,n,l 11i with section 120.57, F.S. Any petition for administrative hearing must cont111Y w111 sections 40C-1.511 and 40C-1.521, F.A.C., must be filed within fourteen (I,I) �, receipt of the request for additional information, and must be filed with lilt,I )In1u,,l , ;” 11I in Palatka. Please be advised, pursuant to subsection 40C-1.605(5), F.A.C., any application which has not been technically completed within ninety (90) days from the date of receipt of a request for additional information by the District, will be prepared for an Intent to Deny at the next timely Governing Board meeting. If you require more than the allotted ninety (90) days, please indicate this to the staff. In addition, no construction shall begin on the proposed project until a permit is issued by the St. Johns River Water Management District. This is pursuant to subsection 40C-4.041(1), F.A.C., which states in relevant part, "unless expressly exempt an individual or general environmental resource permit must be obtained from the District under Chapter 40C-4, 40C-40, 40C-42, 40C-44, or 40C400, F.A.C. prior to the construction, alteration, operation, maintenance, removal or abandonment of any dam, impoundment, reservoir, appurtenant work or works...." If you have any questions, please do not hesitate to call me at (407)984-4940. Sincerely, Ralph Brown, P.E. Department of Resource Management RB/RB cc: Permit Data Services -RAIL John Juilianna Mark Gronceski Martha Campbell Whitney Green YY"