| 2013-05-29 13:19:34 | COMMENTS: |
| | |
| | I REVIEWED THE SUBJECT PLANS (S&S 4/19/13) AND DRAINAGE |
| | CALCULATIONS (REVISED APRIL 2013) AND OFFER THE |
| | FOLLOWING COMMENTS: |
| | 1. PLAN SHEET 4 OF 12 CALLS OUT HDPE PIPE BUT |
| | EXFILTRATION DETAIL AND TYPICAL SECTION A-A ON SHEET 5 |
| | OF 12 SHOW RCP OR SLOTTED RCP PIPE. |
| | 2. ON PLAN SHEET 4 OF 12, DRAINAGE STRUCTURE A7 IS |
| | LISTED AS TYPE "C" W/ C.I. WHAT IS C.I.? |
| | 3. STRUCTURE A6 SHOULD HAVE A WEIR STRUCTURE FOR |
| | CONTROL TO KEEP STORMWATER RUNOFF FROM MALVERNE (VIA |
| | STRUCTURE A7) BACKFEEDING INTO THE ONSITE SYSTEM. |
| | CONTROL MAY NEED TO BE HIGHER THAN 14.3 IN CASE |
| | MALVERNE IS REGRADED. |
| | 4. FOR EXISTING DISCHARGE RATE, THE RAINFALL INTENSITY |
| | SHOULD BE AT THE MINIMUM TIME OF CONCENTRATION, NOT THE |
| | TOTAL DAILY RAINFALL FOR THE DESIGN STORM. THE 1987 |
| | FDOT DRAINAGE MANUAL CONTAINS |
| | INTENSITY-DURATION-FREQUENCY CURVES. |
| | 5. DRAINAGE CALCULATIONS SHOW MINIMUM EXFILTRATION |
| | TRENCH LENGTH OF 65 LINEAR FEET. PLAN SHEET 4 OF 12 |
| | CALLS OUT ONLY 60 LINEAR FEET OF EXFILTRATION TRENCH |
| | (35' + 25'). |
| | 6. 2:1 SLOPE IN DETENTION AREA (SECTION A-A ON SHEET 5 |
| | OF 12) MAY BE DIFFICULT TO MAINTAIN. |
| | 7. SWPPP SHEET 8 OF 12: |
| | A. SILT FENCE AROUND STRUCTURES IN PAVEMENT IS NOT |
| | EFFECTIVE. CONSIDER WRAPPING THE GRATES. |
| | B. GUTTER BUDDIES OR OTHER BMP MAY BE REQUIRED FOR |
| | INLETS ON SOUTHERN BLVD AND DIXIE HWY. |
| | 8. SIDEWALK EASEMENT AT DRIVEWAY SOUTH OF THE DRIVETHRU |
| | WILL BE NEEDED (THIS MAY ALREADY HAVE BEEN PROVIDED). |
| | 9. FDOT PERMIT WILL BE NEEDED FOR THE WORK ON SOUTHERN |
| | BLVD AND DIXIE HWY. |
| | |
| | TRACY L. WARD, P.E. |
| | SENIOR STORMWATER ENGINEER |
| | CITY OF WEST PALM BEACH |
| | ENGINEERING AND PUBLIC WORKS DEPARTMENT |
| | 401 CLEMATIS ST., 4TH FLOOR |
| | WEST PALM BEACH, FL 33401 |
| | PHONE: 561-494-1120 |
| | FAX: 561-494-1116 |
| | CELL 561-351-0510 |
| | [email protected] |