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Home My WebLink About1990 04 17 - Access RoadsLINDAHL, BROWNING FERRARI & HELLSTROM, INC. CONSULTING ENGINEERS, PLANNERS & SURVEYORS JUPITER • STUART • FORT PIERCE • VERO BEACH 1 RICHARD E. WILSON, P.E. PROJECT MANAGER 10 CENTRAL PARKWAY, SUITE 420 2065 15TH AVENUE STUART, FLORIDA 34994 VERO BEACH, FLORIDA 32960 (407) 286-3883 • (407) 746-2311 (407) 567-2156 • (407) 567-2065 LINDAHL, BROWNING, FERRARI & HELLSTROM, INC. CONSULTING ENGINEERS, PLANNERS & SURVEYORS 2065 15TH AVENUE VERO BEACH, FLORIDA 32960 (407) 567-2156 (407) 567-2065 0417901 April 17, 1990 David W. Fisher Interim City Engineer City of Sebastian P.O. Box 780127 Sebastian, Florida 32978 RE: Engineering Evaluation and Preliminary Cost Estimate - Chesser's Gap Police Station Access Roads Dear Mr. Fisher: 90-132 Thank you for the opportunity to provide professional engineering services for the City of Sebastian. As detailed in the Notice to Proceed dated April 12, 1990, Lindahl, Browning, Ferrari & Hellstrom, Inc. has been retained to perform and provide the fol- lowing: 1) Review the owner's proposed engineering design for the sub- ject access roads and evaluate regarding whether appropriate for the instant case. Comment on alternative general engineering designs for same that might be as or more appropriate. 2) Provide itemized preliminary cost estimate(s) for the con- struction of each access road per the owner's proposed design and for same pursuant to any alternative engineering design(s) addressed in item #1 above. With regard to the emergency access road, Mosby and Associates do not at this time intend to design an access road. For this reason, the access road will not be addressed within the scope of this evaluation. STUART JUPITER FT. PIERCE VERO BEACH Review and Evaluation On Monday, April 16, 1990, I met with Randy Mosby, P.E. and Bruce Moia at the Vero Beach office of Mosby and Associates, Inc. to obtain preliminary engineering design information for the proposed roadway improvements. From the information available, it appears that the design for Fleming Street consists of: 1) A deceleration and right turn lane on S.R. 512 2) Entrance median 3) 24 foot wide pavement section 4) Curb and gutter 5) 15-24 inch RCP storm sewer pipe and inlets 6) 8 inch PVC sanitary sewer 7) Water line(s) 8) Drives for parcels fronting on Fleming Street The deceleration and turn lane improvements generally consist of a deceleration taper in range of 180 lineal feet, a 12 foot wide turn lane 75 to 100 feet in length, grading of the existing road- side ditch to accommodate the lane addition and possibly replace- ment of the existing 36 inch culvert. The deceleration and right turn lane on S.R. 512 would be con- sidered a requirements to provide a safe entry into the P.U.D. Traffic volumes generated by the development during peak hours could result in stacking on S.R. 512 without the lane. The con- struction of the police station alone may not warrant the lane addition. That determination would be based on a study of the an- ticipated traffic generated by the proposed facility. From the Dedication Agreement it is unclear which party, the Dedicator or the City, is obligated to construct the S.R. 512 im- provements at the intersection. The entrance median is approximately 8 feet wide and 150 feet long and is designed with a median curb. The median provides an entrance feature and is noted in the Agreement. The 24 foot wide pavement section will consist of 1 1/2 inches of asphalt, 6 inches of base, and 8 inches of stabilized subgrade. Given the function of the roadway as an access to the non- residential parcels and ultimately as an entrance to the remainder of the P.U.D. this section is appropriate. The proposed plan include The curb and gutter seems Sion relative to the ov( proposed 80 foot right o modate a swale drainage s, for the curb and gutter. Fleming would require the s a two foot curb and gutter section. to be the result of a marketing deci- rall appearance of the project. The E way is more than adequate to accom- ,stem thereby eliminating the necessity In addition, any future widening of removal of the curb and gutter. Conveyance of storm run-off will accomplished by the use of rein- forced concrete pipe ranging in size from 15 inches to 24 inches in diameter. The inlets would be located in the curb and gutter section with the pipe running just outside the road above, future widening would require the relocation of at least the inlets. Any discussion of the storm sewer system must address provisions for the stormwater management system, i.e. retention/ detention lakes, quality treatment, and discharge structures. Mosby and As- sociates, Inc. apparently have not included the subject parcel in calculations for stormwater storage in the P.U.D. lake system. What this means is that on-site storage will be required and dis- charge to the proposed storm sewer pipe must be limited to pre - development rates. Area must then be set aside for on-site stormwater retention thus limiting the amount of previous area that can be constructed. The net effect of the plan is that the City may be asked to construct a section of a stormwater con- veyance system that does not completely fulfill the requirements of the parcel. Sanitary sewer service will be provided via an eight inch PVC gravity sewer. The sewer is to be located in the centerline of Fleming Street at a depth of approximately ten feet. The depth is the result of the lift station siting near the proposed site and the distance to the upper end of the service area. The sanitary sewer begins at a depth of four feet and slopes down to the lift station. The longer the run, the deeper the line. Assuming that the proposed site would be served by this line an adjustment to the costs borne by the City to install the deepest section of sewer may be appropriate. The Owner has not finalized plans for water and fire service for the P.U.D. Water lines would not be located within the pavement section with the possible exception of service laterals. Instal- lation of the water line(s) on the project side of the road would reduce the need to cross the road with water lines. In addition to the proposed site two entrances are planned from the extension of Fleming Street to adjacent parcels. If the loca- tion of the entrances is indeed set, the entrance provisions should be included in the construction. The cost of the entrances however, should be assumed by the Dedicator. Alternative The alternative to the proposed roadway plan consists of a 24 foot wide pavement section, stabilized shoulders and a swale drainage system including inlets and pipe. The difference between this alternative and the proposed plan is primarily the removal of the curb and gutter and the use of the swales for drainage. The advantages of the alternative section include: 1) Flexibility - The street can be widened without removal of curb and gutter, inlets or pipe. The inlets and pipe can be located nearer to the right of way lines to avoid any future conflict with improvements. 2) Cost - The attached cost estimates reflect the savings. 3) Compatibility - The majority of the surroundings develop- ments appear to utilize swale drainage. 4) Capacity - The swale section when used with inlets and pipe provides greater stormwater holdings capacity than curb and gutter. This can result in greater spacing between inlets and a corresponding reduction in cost. The disadvantages to the alternative are: 1) Maintenance - the swale sections would be grassed and would therefore require maintenance, i.e, cutting, regrading of washout areas, clogged culverts). 2) Driveways - Each driveway would require either a culvert or a swale section in the drive to accommodate drainage flow. 3) Compatibility - The Chesser's Gap Project appears to include the use of curb and gutter. Conclusions The road construction plans under development by Mosby and As- sociates, Inc. are intended to ultimately serve the Chesser's Gap P.U.D. The pavement section including turning lanes, entrance median, curb and gutter; the depth of the sanitary sewer lines; size and configuration of the adjacent parcels, are above and beyond the requirements of "Parcel A" the proposed Police Station site. The minimum road requirements for access to the site are shown on the following cost estimate for the alternate section. The projected grading and paving costs are approximately $21,150. The remaining items consisting of drainage structures, water dis- tribution system, and sewage collection system are required for the site to be served by the infrastructure improvements planned for the Chesser's Gap P.U.D. The questions that must be answered at this point are: 1) Is the City of Sebastian responsible for the utility im- provements or just for the grading, paving and possibly drainage improvements? 2) Is the City obligated to provide a pavement section com- patible with the Chesser's Gap P.U.D. or should the Dedicator bear the additional costs associated with the planned improvements? 3) Is the site not included in the Chesser's Gap P.U.D. Surface Water Management System? Is storage allocated in the lake system for this site? Upon clarification of these items, the City can establish the true cost of the road improvements and also some of the site development constraints with regard to retention/detention facilities. FLEMING STREET IMPROVEMENTS Preliminary Estimate of Quantities Item Estimated Unit Total No Description Quantity Unit Price Price 1.Grading/Paving: Rough Grading 1 LS $2,:000.00 $2,000.00 8" Stabilized Sub -Grade 1400 SY $2.50 $3,500.00 6" Base, Prime 1400 SY $5.00 $7,000.00 1 1/2" Asphalt 1100 SY $3.00 $3,300.00 Median Curb 310 LF $8.00 $2,480.00 Curb & Gutter 1100 LF $6.00 $6,600.00 Seed & Mulch 2800 SY $0.50 $1,400.00 Total Grading/Paving: 3 EA $300.00 $26,280.00 2.Drainage: 15" Diameter R.C.P. 24 LF $16.00 $384.00 18" Diameter R.C.P. 30 LF $19.00 $570.00 24" Diameter R.C.P. 275 LF $24.00 $6,600.00 Inlets w/Grate 4 EA $2,200.00 $81800.00 Total Drainage System: $16,354.00 3.Water Distribution System: 8" Diameter P.V.C. 170 LF $12.00 $2,040.00 Water Services 3 EA $300.00 $900.00 8" G.V. & Box 2 EA $500.00 $1,000.00 Fire hydrant 2 EA $1,500.00 $3,000.00 Total Water Distribution System: $6,940.00 4.Sewage System: 8" Diameter P.V.C. 500 LF $19.00 $9,500.00 Sanitary Manholes 3 EA $1,500.00 $4,500.00 Sanitary Services 3 EA $300.00 $900.00 Total Sewage System: $14,9,00.00 TOTAL $64,474.00 S.R. 512 and FLEMING STREET INTERSECTION IMPROVEMENTS 1.Grading/Paving: Rough Grading 1 LS $500.00 $500.00 8" Stabilized Sub -Grade 375 SY $2.50 $937.50 6" Base, Prime 375 SY $5.00 $1,875.00 1 1/2" Asphalt 350 SY $3.00 $1,050.00 Regrade Ditch 300 LF $3.00 $900.00 Flush tieader.Curb 47 LF $8.00 $376.00 Total Grading/Paving: $5,638.50 2.Drainage: Culvert Replacement 100 LF "$30.00 $3,000.00 Rip -Rap Endwall 1 LS $500.00 $500.00 Total Drainage System: $3,500.00 TOTAL $9,138.50 FLEMING STREET Preliminary Item No Description IMPROVEMENTS (ALTERNATE) Estimate of Quantities Estimated Unit Quantity Unit Price Total Price 1.Grading/Paving: Rough Grading 1 LS $2,000.00 $2,000.00 8" Stabilized Sub -Grade 1900 SY $2.50 $4,750.00 6" Base, Prime 1400 SY $5.00 $7,000.00 1 1/2" Asphalt 1300 SY $3.00 $3,900.00 Swale Grade 1400 SY $1.50 $2,100.00 Seed & Mulch 2800 SY $0.50 $1,400.00 Total Grading/Paving: $21,150.00 2.Drainage: 15" Diameter R.C.P. 24 LF $16.00 $384.00 18" Diameter R.C.P. 80 LF $19.00 $1,520.00 24" Diameter R.C.P. 170 LF $24.00 $4,080.00 Inlets w/Grate 2 EA $2,200.00 $4,400.00 Total Drainage System: $10,384.00 3.Water Distribution System: 8" Diameter P.V.C. 170 LF $12.00 $2,040.00 Water Services 3 EA $300.00 $900.00 8" G.V. & Box 2 EA $500.00 $1,000.00 Fire Hydrant 2 EA $1,500.00 $3,000.00 Total Water Distribution System: $6,940.00 4.Sewage System: 8" Diameter P.V.C. 500 LF $19.00 $9,500.00 Sanitary Manholes 3 EA $1,500.00 $4,500.00 Sanitary Services 3 EA $300.00 $900.00 Total Sewage System: $14,900.00 TOTAL $53,374.00 ACCESS EASEMENT DRIVEWAY IMPROVEMENTS Preliminary Estimate of Quantities Item Estimated Unit Total No Description Quantity Unit Price Price 1.Grading/Paving: Rough Grading 1 LS $1,500.00 $1,500.00 8" Stabilized Sub -Grade 1000 SY $2.50 $2,500.00 6" Base, Prime 1000 SY $5.00 $5,000.00 Curb/Gutter 800 LF $8.00 $6,400.00 1 1/2" Asphalt 930 SY $3.00 $2,790.00 Fill 200 SY $1.50 $300.00 Flush Header Curb 47 LF $8.00 $376.00 Total Grading/Paving: $18,866.00 2.Drainage: 18" Diameter R.C.P. 200 LF $19.00 $3,800.00 30" Diameter R.C.P. 50 LF $30.00 $1,500.00 Rip -Rap Endwalls 1 LS $500.00 $500.00 Inlets 2 EA $2,200.00 $4,400.00 Total Drainage System: $10,200.00 TOTAL $29,066.00 v ACCESS EASEMENT DRIVEWAY IMPROVEMENTS (ALTERNATE) Preliminary Estimate of Quantities Item Estimated Unit Total No Description Quantity Unit Price Price 1.Grading/Paving: Rough Grading 1 LS $1,500.00 $1,500.00 8" Stabilized Sub -Grade 1000 SY $2.50 $2,500.00 611 Base, Prime 1000 SY $5.00 $5,000.00 Swale 800 LF $5.00 $4,000.00 Fill 200 SY $1.50 $300.00 1 1/2" Asphalt 930 SY $3.00 $2,790.00 Total Grading/Paving: $16,090.00 2.Drainage: 36" Diameter R.C.P. 50 LF $30.00 $1,500.00 Rip -Rap Endwalls 1 LS $500.00 $500.00 Total Drainage System: $2,000.00 TOTAL $18,090.00