stormwater management plan c-25 - Arlingtonva
BEST MANAGEMENT PRACTICES MAP LEGEND:
ON-SITE UN-DETAINED AREA = 51,353 SF OR 1.18 ACRES.
ON-SITE DETAINED AREA = 169,066 SF OR 3.88 ACRES
SITE DRAINAGE AREA = 220,419 SF OR 5.06 ACRES
STORMWATER MANAGEMENT PLAN
C-25
BUILDING 'A' BMP COMPUTATIONS
BUILDING 'C' BMP COMPUTATIONS
BUILDING 'D' BMP COMPUTATIONS
THE STORMWATER MANAGEMENT REQUIREMENTS FOR QUANTITY CONTROL WILL BE MET THROUGH THE IMPLEMENTATION OF THREE (3) UNDER GROUND DETENTION VAULTS WHICH WILL BE DESIGNED TO MEET THE 10-YR STORM EVENT REQUIREMENTS. THE APPROXIMATE TOTAL CAPACITY OF THE VAULTS WILL BE 5,500 CF. THE TOTAL VEHICULAR RELATED PAVEMENT EXPOSED TO THE ATMOSPHERE ASSOCIATED WITH THIS DEVELOPMENT IS 73,993 SF OR 1.70 ACRES. RUNOFF FROM VEHICULAR RELATED PAVEMENT WILL BE TREATED BY A COMBINATION OF BUT NOT LIMITED TO STORMFILTERS AND BIORETENTION, ETC. FOR THIS SUBMISSION, IT IS ASSUMED THAT APPROXIMATELY 66% OF THE VEHICULAR RELATED PAVEMENT WILL BE TREATED. PLEASE NOTE THAT FINAL QUANTITIES ARE PENDING FINAL ENGINEERING DOCUMENTS.
NOTE:
THE STORMWATER DESIGN PRESENTED HEREON IS BASED ON THE STORMWATER LANGUAGE IN THE ARLINGTON COUNTY STORMWATER MANUAL: A GUIDE TO STORMWATER REQUIREMENTS FOR LAND DISTURBING ACTIVITIES IN ARLINGTON COUNTY, THE FACT THAT A 4.1 SITE PLAN WAS APPROVED PRIOR TO JULY 1, 2012, AND THE IS NO PROPOSED INCREASE IN THE AMOUNT OF PEAK FLOW RATE, DISCHARGE VOLUME, OR PHOSPHOROUS LOADING FROM ANY SITE OUTFALL PROPOSED WITH THIS 4.1 AMENDMENT, THE SUBJECT PLAN MAY BE CONSIDERED GRANDFATHERED UNDER PLAN (FESP) SUBMISSION, WITHIN THE TIME FRAMES SPECIFIED FOR GRANDFATHERED PLANS, THE APPLICANT RESERVES THE RIGHT TO SUBMIT A FINAL DESIGN BASED ON THE 2009 GENERAL PERMIT STANDARDS, OR TO SUBMIT A FINAL DESIGN AND OPT INTO THE DETERMINATION AS TO WHICH STORMWATER STANDARDS THE FESP WILL BE DESIGNED FOR, AS DESCRIBED ABOVE, SHALL BE AT THE SOLE DISCRETION OF THE APPLICANT.
BMP/SWM CALCULATIONS
C-26
ON-SITE UN-DETAINED AREA = 51,353 SF OR 1.18 ACRES.
ON-SITE DETAINED AREA = 169,066 SF OR 3.88 ACRES
SITE DRAINAGE AREA = 220,419 SF OR 5.06 ACRES
STORMWATER MANAGEMENT PLAN
C-25
BUILDING 'A' BMP COMPUTATIONS
BUILDING 'C' BMP COMPUTATIONS
BUILDING 'D' BMP COMPUTATIONS
THE STORMWATER MANAGEMENT REQUIREMENTS FOR QUANTITY CONTROL WILL BE MET THROUGH THE IMPLEMENTATION OF THREE (3) UNDER GROUND DETENTION VAULTS WHICH WILL BE DESIGNED TO MEET THE 10-YR STORM EVENT REQUIREMENTS. THE APPROXIMATE TOTAL CAPACITY OF THE VAULTS WILL BE 5,500 CF. THE TOTAL VEHICULAR RELATED PAVEMENT EXPOSED TO THE ATMOSPHERE ASSOCIATED WITH THIS DEVELOPMENT IS 73,993 SF OR 1.70 ACRES. RUNOFF FROM VEHICULAR RELATED PAVEMENT WILL BE TREATED BY A COMBINATION OF BUT NOT LIMITED TO STORMFILTERS AND BIORETENTION, ETC. FOR THIS SUBMISSION, IT IS ASSUMED THAT APPROXIMATELY 66% OF THE VEHICULAR RELATED PAVEMENT WILL BE TREATED. PLEASE NOTE THAT FINAL QUANTITIES ARE PENDING FINAL ENGINEERING DOCUMENTS.
NOTE:
THE STORMWATER DESIGN PRESENTED HEREON IS BASED ON THE STORMWATER LANGUAGE IN THE ARLINGTON COUNTY STORMWATER MANUAL: A GUIDE TO STORMWATER REQUIREMENTS FOR LAND DISTURBING ACTIVITIES IN ARLINGTON COUNTY, THE FACT THAT A 4.1 SITE PLAN WAS APPROVED PRIOR TO JULY 1, 2012, AND THE IS NO PROPOSED INCREASE IN THE AMOUNT OF PEAK FLOW RATE, DISCHARGE VOLUME, OR PHOSPHOROUS LOADING FROM ANY SITE OUTFALL PROPOSED WITH THIS 4.1 AMENDMENT, THE SUBJECT PLAN MAY BE CONSIDERED GRANDFATHERED UNDER PLAN (FESP) SUBMISSION, WITHIN THE TIME FRAMES SPECIFIED FOR GRANDFATHERED PLANS, THE APPLICANT RESERVES THE RIGHT TO SUBMIT A FINAL DESIGN BASED ON THE 2009 GENERAL PERMIT STANDARDS, OR TO SUBMIT A FINAL DESIGN AND OPT INTO THE DETERMINATION AS TO WHICH STORMWATER STANDARDS THE FESP WILL BE DESIGNED FOR, AS DESCRIBED ABOVE, SHALL BE AT THE SOLE DISCRETION OF THE APPLICANT.
BMP/SWM CALCULATIONS
C-26
