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Home My WebLink AboutZ-8338 Map 3'STER PAD TE NAY STORMWATER DETENTION CALCULATIONS AREA - 3.51 Acres Average Slope - 10% Undeveloped Runoff Coefficient 0.55 Time of Concentration (min.) 10 25 Year Rainfall Intensity (in./hr.) 7.1 Building 30,600 sf @ 0.92 28,152 / Paved Areas 62,000 sf 0 0.92 57,040 / Lawn & Landscaping 60,466 sf ® 0.44 26,605 153,066 111,797 Developed "C" Value = 111,797/153,066 = 0.73 JDeveloped Runoff Coefficient 0.73 Time of Concentration (min.) 5 25 Year Rainfall Intensity (in./hr.) 8.5 / / / / Differential Runoff Rate (R) = 0.73(8.5)-0.55(7.1) = 2.30 in./hr Simplified Volume Formula Volume Required = R x A x Tc x 60 =2.30x3.51 x5x60 = 2,422 cubic foot Volume Provided 36" RCP x 388' = 2,743 cubic foot 5' dia Inlets x 35' = 687 cubic foot 3,430 cubic foot On -Site & Off -Site Release 25 Year Undeveloped Flow Acreage 6.92 Acres Runoff Coeffecient 0.55 Time of Concentration 10 min. 25 Year Rainfall Intensity 7.1 in./hr. Q = 0.55(7.1)(6.92) = 27.0 cfs Use 18" RCP as Outlet Q = C x A x (2gh) 1/2 Q = 0.6 x 1.77 x (2 x 32.2 x 9.85) /2 = 26.7 cfs < 27.0 cfs !d A It 16ti "S A `.p_ z o 6 0� ?� REGI'TE11ED � �^ PR0FESS10N.AL765M� ENGINEER" T � A~o- z ®�® No.5033 Tjy y, p�, �' a U o ter' mz� U U) z O c a LU O p r�z HG 30 0 30 Scale 1 " = 30 ft .o GENERAL SITE UTILITY CONSTRUCTION NOTES, 1. SEE ARCHITECTURAL DRAWINGS FOR DETAILS GRADING AT BUILDINGS, STEPS, WALKS, WALLS AND OTHER STRUCTURES. 2. FINISH CONTOURS AND GRADES SHOWN ARE FOR FINISHED SURFACES, ALLOWANCES SHALL BE MADE FOR PAVEMENTS, SLABS, TOPSOIL, SOD, ETC, UNIFORM PLANES AND SURFACES SHALL BE SHAPED BETWEEN FINISHED SPOT ELEVATIONS AND/OR FINISH CONTOURS SHOWN. MINIMUM PAVEMENT SLOPES SHALL BE 1%, MINIMUM FINISH SLOPES ON GRASS OR SOD SURFACES SHALL BE 1%, MINIMUM LONGITUDINAL CONCRETE CURB & GUTTER SLOPE SHALL BE 0.6%, SPILLOUT CURB SHALL BE USED ON THE HIGH SIDE OF PAVEMENT AND AT DISCHARGE POINTS. 3. THE CONTRACTOR SHALL CONTROL EROSION ON THE SITE. ALL SLOPES SHALL BE FERTILIZED, SEEDED AND MULCHED (OR LANDSCAPED) AS SOON AS POSSIBLE. THE CONTRACTOR SHALL FILE A NOTICE OF INTENT WITH THE ARKANSAS DPC&E. THE SITE SHALL BE GRADED TO MAINTAIN POSITIVE DRAINAGE DURING CONSTRUCTION, WATER SHALL NOT BE ALLOWED TO POND. 4. ALL AREAS TO BE CUT OR FILLED SHALL BE CLEARED AND GRUBBED. THE MAXIMUM FILL SLOPE SHALL BE 3:1. ALL FILLS SHALL BE MADE IN 8" LIFTS AND COMPACTED, AT OPTIMUM MOISTURE CONTENT TO 95% OF MODIFIED PROCTOR DENSITY (ASTM D-1557), AS DETERMINED BY IN -PLACE DENSITY TESTS. BORROW AND FILL MATERIAL SHALL BE SELECT CLAY SAND OR SANDY CLAY HAVING A LIQUID LIMIT LESS THAN 40 OR OTHER APPROVED FILL. FILL SOILS CLASSIFYING AS SC OR GC ACCORDING TO THE UNIFIED SOILS CLASSIFICATION SYSTEM ARE CONSIDERED SUITABLE. SHALE MATERIAL USED IN FILL SHALL BE COMPACTED AT 3% ABOVE OPTIMUM MOISTURE CONTENT WITH A VIBRATORY SHEEPS FOOT COMPACTOR. 5. THE CONTRACTOR SHALL COORDINATE WITH EACH UTILITY COMPANY PRIOR TO ANY EXCAVATION. ANY DAMAGE TO UTILITY LINES CAUSED BY THE CONTRACTORS OPERATIONS SHALL BE REPAIRED AT THE CONTRACTORS EXPENSE. THE CONTRACTOR SHALL VERIFY THE HORIZONTAL AND VERTICAL ALIGNMENT OF EXISTING AND PROPOSED STORM SEWER, SANITARY SEWER AND WATER LINES TO ENSURE THAT THEY ARE INSTALLED WITH ADEQUATE COVER AND CLEARANCE . ALL ROUGH GRADING SHALL BE COMPLETE BEFORE INSTALLATION OF STORM SEWER, SANITARY SEWER AND APPURTENANCES, WATER MAINS, SERVICES AND APPURTENANCES. ALL UTILITY TRENCHES SHALL BE BACKFILLED AND COMPACTED WITH SELECT MATERIAL AS SPECIFIED IN NOTE #4 ABOVE. 6. THE CONTRACTOR SHALL COMPLY WITH ALL APPLICABLE LAWS, CODES AND ORDINANCES GOVERNING WORK OF THIS TYPE. 7. THE INSTALLATION OF ALL CULVERT PIPE TO BE IN ACCORDANCE WITH AHTD SPECIFICATIONS. 8. ALL EXISTING IMPROVEMENTS WHICH INTERFERE WITH THE WORK, AND ARE NOT TO BE SAVED SHALL BE REMOVED AND DISPOSED OF. iMPROVFMFNTR IN THE RIGHT-OF-WAY WHICH ARE TO REMAIN SHALL BE PROTECTED BY THE CONTRACTOR. 9. ALL REINFORCED CONCRETE PIPE (RCP) SHALL BE CLASS III WITH BELL AND SPIGOT TYPE JOINTS. PIPE, MATERIAL AND INSTALLATION SHALL BE IN CONFORMANCE WITH APPLICABLE ARKANSAS HIGHWAY AND TRANSPORTATION DEPARTMENT (AHTD) STANDARD CONSTRUCTION SPECIFICATIONS. 10. ALL CORRUGATED METAL PIPE SHALL MEET OR EXCEED AHTD REQUIREMENTS FOR GAUGE AND CORRUGATION AND SHALL BE POLYMER COATED IN ACCORDANCE WITH ASTM A-742 AND AASHTO M-246. THE LAST 12" OF EACH LENGTH SHALL BE RECORRUGATED WITH ANNULAR CORRUGATIONS TO ACCEPT CORRUGATED COUPLING BANDS. 11. ALL WATER MAINS AND SEWER MAINS AND THEIR APPURTENANCES INCLUDING INSTALLATION, SHALL COMPLY WITH THE LATEST CENTRAL ARKANSAS WATER AND LITTLE ROCK WASTEWATER UTILITY SPECIFICATIONS. CONNECTIONS SHALL NOT BE MADE TO EXISTING LINES UNTIL NEW CONSTRUCTION HAS BEEN TESTED AND APPROVED BY THE UTILITY. 12. THE CONTRACTORS ATTENTION IS SPECIFICALLY CALLED TO THE LOCATION OF THE EXISTING IMPROVEMENTS. THE CONTRACTOR SHALL BE SOLELY RESPONSIBLE FOR DAMAGING ANY EXISTING IMPROVEMENTS WHICH ARE TO REMAIN. PRIOR TO SUBMITTING HIS BID, THE CONTRACTOR SHALL REVIEW THE PLANS AND SPECIFICATIONS. HE SHALT_ VISIT THE SITE AND INSPECT THE CONDITION OF THE SITE AND THE ADJACENT IMPROVEMENTS. ANY EXISTING UTILITIES THAT REQUIRE RELOCATION WILL BE THE RESPONSIBILITIES OF THE CONTRACTOR AND NOT THE OWNER. THE CONTRACTOR WILL HOLD THE OWNER HARMLESS FROM ANY UNFORSEEN COSTS ASSOCIATED WITH THE STREET IMPROVEMENTS. 13. THE CONTRACTOR SHALL CALL "ONE -CALL" FOR LOCATION OF ALL UTILITIES PRIOR TO COMMENCEMENT OF ANY EXCAVATION. 14. ANY EXCESS EXCAVATED MATERIAL, NOT REQUIRED FOR CONSTRUCTION OF FILLS SHALL BE HAULED OFF SITE. 15. THE CONTRACTOR SHALL BE REQUIRED TO POST A MAINTENANCE BOND WITH THE CITY OF LITTLE ROCK FOR THE PUBLIC IMPROVEMENTS ON KANIS ROAD. THE BOND SHALL BE FOR ONE HALF THE COST OF IMPROVEMENTS FOR A ONE YEAR PERIOD.