EA IAA Cut DA-9 at Bakers Inlet
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CESAD-ET-CO-M (CESAJ-C0/21Jun97) (ll-2-240a) 1st End Mr. DeVeaux/ dsm/(404) 331-6742 SUBJECT: Advanced Maintenance Dredging of the Atlantic Intracoastal Waterway (IWW) Jacksonville to Miami, in the Vicinity of Bakers Haulover Inlet, Dade County, Florida Commander, South Atlantic Division, U.S. Army Corps of Engineers, 77 Forsyth Street, S.W., Room 322, Atlanta, Georgia 30303-3490 10 July 1997 FOR THE COMMANDER, JACKSONVILLE DISTRICT, ATTN: CESAJ-CO 1. Your request to perform advanced maintenance in subject channel is approved subject to completing all appropriate environmental documentation, coordination, and clearance. Approval of the Memorandum of Agreement with the Florida Inland Navigation District is also required. 2. You should continue to monitor the cost of maintenance to assure that the proposed advanced maintenance dredging results in the least costly method of maintaining the channel. FOR THE DIRECTOR OF ENGINEERING AND TECHNICAL SERVICES: ~&Peei JR., PE~ . Chief, Construction-Operations ~ Directorate of Engineering and Technical Services !<. c v ~...': 7 Yv / 9 7 DEPARTMENT OF THE ARMY JACKSONVILLE DISTRICT CORPS OF ENGINEERS P. 0. BOX 4970 JACKSONVILLE, FLORIDA 32232-0019 REPLY TO ATTENTION OF CESAJ-CO (ll-2-240a) 21 June 1997 ~MORANDUM FOR CDR, USAED (CESAD-ET-CO-M), ATLANTA, GA 30335 SUBJECT: Advanced Maintenance Dredging of the Atlantic Intracoastal Waterway (IWW) Jacksonville to Miami, in the Vicinity of Bakers Haulover Inlet, Dade County, Florida 1. Reference ER 1130-2-520. 2. Advanced maintenance dredging is proposed for the IWW in the vicinity of Bakers Haulover Inlet to reduce the frequency of dredging required for this reach of the IWW. The advanced maintenance will provide the most efficient and cost effective solution for maintaining the channel at project depths. The authorized project is 125 feet wide with a depth of 10 feet mean low water. Overdepth dredging is not an option because existing project depth was attained by excavating through rock. Recent dredging contracts in this portion of the IWW provided a safe navigation channel for less than a year. Within a year after dredging, complaints from the Coast Guard and users of this reach of the IWW have been received. The channel is presently reported to be 50 feet wide and 6 feet deep, and is able to serve only navigation interests with very shallow drafts. 3. Enclosure 1 is an Area Map which shows the location of the project. Bakers Haulover Inlet is a man-made inlet, with a relatively high top of rock elevation throughout its flood tide shoal. Enclosure 2 provides a hydrographic survey overlayed onto the Federal inlet channel and IWW channel. Please note the area for which we are requesting advanced maintenance coincides with the flood tide shoal. Enclosure 3 shows the top of rock elevations in the area. We intend to dredge the flood tide CESAJ-CO SUBJECT: Advanced Maintenance Dredging of the Atlantic Intracoastal Waterway (IWW) Jacksonville to Miami, in the Vicinity of Bakers Haulover Inlet, Dade County, Florida shoal down to two feet above rock, which will create a settling basin. In the past when the IWW channel was dredged, the dredging effectively just cut off the western edge of this flood tide shoal, and as the inlet processes continued, the flood tide shoal simply extended back into the IWW channel. A Water Quality Certificate for doing this work has been submitted to the Florida Department of Environmental Protection. All dredged material will be placed on Bal Harbour Beach. 4. According to the project cost estimate, the total cost to dredge the 22,000 cubic yards of material in the IWW would be $661,900. Alternatively, the total cost to dredge the 142,000 cubic yards in the flood tide shoal (including the IWW portion) would be $1,359,525. Since all the material to be dredged is beach quality, it would be placed on Bal Harbour Beach, located immediately south of Bakers Haulover Inlet. Enclosure 4 compares the dredging costs for the with and without advanced maintenance alternative. We anticipate that the frequency of dredging is a non-linear function proportional to the quantities dredged. We predict that by dredging this settling basin, the dredging frequency would be reduced from the annual requirement to a four year period. This would result in a project savings of over $1,288,000 every four years, and at the same time producing a channel that would be truly navigable for four years or possibly more. 5. ER 1130-2-520 allows the District to perform advanced maintenance dredging with your permission. Without your approval, the District will have to dredge the channel every year to every other year. Consequently, the district will fail to maintain the project at authorized dimensions during portions of the interval and maintenance of the channel will cost more. Prior to future advanced maintenance for this location of the IWW, the District will evaluate and affirm the effectiveness of advanced maintenance. CESAJ-CO SUBJECT: Advanced Maintenance of the Atlantic Intracoastal Waterway (IWW) Jacksonville to Miami, in the Vicinity of Bakers Haulover Inlet, Dade County, Florida 6. Request approval of subject advanced maintenance for the area shown at Enclosure 2. The Florida Inland Navigation District (as local sponsor) , is willing to pay for the additional cost of the first advanced maintenance activity. A Memorandum of Agreement to accept their funds is being processed. FOR THE COMMANDER: Encls ~~~~c~~tcconstruction-Operations Division Sunny Isles LOCATION OF WORK Haulover Beach Park Ba I Harbour Miami VICINITY MAP , · ENCLOSURE 1 2.1 p.6 2., 2.6 Wf>-6 2.6 2.~ 2 .s ,.o 2.~ 2.s u '·J '·''.1 l\&:01 10.& 10.2 f:l h'·A 10.0 10.0 11.0 10.& 10.i iulb ADVANCED MAINTENANCE AREA r • "J .. / J ·r .....9 / '... '<?..,_~:j' J .... ,/•1 ENCLOSURE 2 STA 0·00 CUT·J STA 8·q7.62 CUT·2 I I I .I I I I .----@------------------------_j I 13 7 • CB·BH'l6·2J • • CB-BH'l6·24 __ ---- - _J I I CB· H·~0· " - \ J I ' ~,, ' ROCK CONTOURS 7.S 10.6 @ • - - u ,... - -L-7 - - " .... CB·BH'lG· I<! .,...._ -- / / ..,...)rt.:? ) ,....I 7.0 .,,... ·~ I ~ ~CB·BHji'l0..''l / ... .. ::- ' i'" / ~ CB·BH·Hl0.. I ...lie.G LEGEND• 8. 0 - El£YATIOH OF TOP OI' R()Q( @ C8·'16· J;>alA£ OOAll<G 0€SIGAATIOH ..W LOCATION 8£t.OV l<E"'4 LOV VATER 8.0- El£YATIOH OF TOP Of ROO< \IP·'l6-::?• VASH l'fl()OC 0€SIGAATIOH H<O LOCATION e€t.OV HE.Hf LOV VATEf\ HOlE• CORt 800; rt.Gs OLO€A ltw-1 I"t<w; VER£ USEO FOR lOP Of AOCK OAlA OM...T N-0 AA£ OESIGNltlEO lt£ SAf-€ #\S \l'i'SH PROBE.S. GRAPHIC SCALE 100· 0 100· ioo· SHEET 5 ENCLOSURE 3 DREDGING COST FOR IWW - VICINITY OF BAKERS HAULOVER INLET WITH AND WITHOUT ADVANCE MAINTENANCE Estimated shoaling rate =22,000 cubic yards per year in the IWW - vicinity of Bakers Haulover Inlet. Mobilization and Demobilization cost are slightly higher for advanced maintenance for extra pipeline. E&D costs are slightly higher for Adv Maint due to additional surveying and material sampling costs. Estimates assume a 20 percent contingency factcir. Existing Condition-No Advance Maintenance - Annual Requirement item quantity unit unit cost cost Mobilization and Demobilization 1job job LS $ 400,000 Dredging 22,000 cu.yds $ 6.00 $ 132,000 Subtotal $ 532,000 E&D $ 90,000 S&A 0.075 $ 39,900 Total Cost of Operation $ 661,900 Dredging Operation Advanced Maintenance (assume 4 year dredging period) item quantity unit unit cost cost Mobilization and Demobilization 1 job LS $ 435,000 Dredging 22,000 cu.yds $ 6.00 $ 132,000 Advanced Dredging 120,000 cu.yds $ 5.00 $ 600,000 Subtotal $ 1,167,000 E&D· $ 105,000 S&A 0.075 $ 87,525 Total Cost of Operation $ 1,359,525 Cost over a 4 year dredging period .without with Adv Maint Adv Maint I Year1 $661,900 $1,359,525 ! Year2 $661,900 I : Year3 $661,900 - Year4 $661,900 I I i 4-year total $2,647,600 $1,359,525 I I Annual Cost $661,900 $ 339,881 I i Potential Savings over 4 year dredging period $1,288,075 ! ! ! Potential Annual Savings $322,019 I I I i i L:\COPM\EXCEL\BH-ADVMN.XLS ! i' ENCLOSURE 4 BA\<(': (( ,,,\ A() / ,)\)l~ CESAD-CO-ON (CESAJ-CO-ON/9 August 1993) (1110-2-1150a) 1st End Mr. Russell/dsm/(404) 331-6745 SUBJECT: IWW J to M - Advance Maintenance, Cut DA-9 Commander, South Atlantic Division, U.S. Army Corps of Engineers, 77 Forsyth Street, SW, Room 313, Atlanta, Georgia 30335-6801 13 August 1993 FOR COMMANDER, JACKSONVILLE DISTRICT, ATTN: CESAJ-CO-ON 1. Your request to perform advanced maintenance dredging in Cut DA-9 is approved. 2. You should continue to monitor the cost of maintenance to assure that the advanced dredging results in the least costly method for maintaining the channel. FOR THE COMMANDER: JOHN J. BLAKE, P.E. Director of Construction-Operations DEPARTMENT OF THE ARMY JAC~SONVILLE DISTRICT CORPS OF ENGINEERS P. 0. BOX 4970 JACKSONVILLE, FLORIDA 32232-0019 REPLY TO ATTENTION OF CESAJ-CO-ON (1130) 9 August 1993 MEMORANDUM FOR Commander, South Atlantic Division, 77:Forsyth Street, s.w., Atlanta, Georgia 30335 SUBJECT: IWW J to M - Advance Maintenance, Cut DA-9 1. Sand material moves through Bakers Haulover Inlet and is deposited in Cut DA-9 over a half mile reach of channel. The quantity of material in the channel is usually around 30,000 to 40,000 cubic yards. Material in the setting basin is usually another 10,000 yards.