Chaucer, I don’t think diverting runoff overland to Proton is an option anyway because it appears that the drains at the door stoops are a necessity. Here are some suggestions for the drainage system you are proposing. 1. SDR-35 PVC could be used in place of RCP to reduce costs. 2. There is approximately 1.9 CFS of runoff coming from the roof. A 12” pipe at 1% is more than adequate. 3. Tie the gutter downspout directly to the drain pipe to limit the amount of water on the sidewalk. 4. Calculate the actual capacity and required capacity of the grate inlets at the doors. Provide this data in the plans. A 24” x 24” grate inlet seems large and may be a pedestrian hazard. Insure that the grate inlet specified is indented for pedestrian use. If possible, located the grate inlet outside of the pedestrian route. 5. Run the pipe adjacent to the building, below the sidewalk being constructed, and cross the parking lot at a perpendicular angle to limit the amount of pavement replacement. Thank you, Chris Robinson, P.E. Grantham & Associates 1919 S. Shiloh Suite #440, LB 8 Garland, TX 75042 972-864-2333 ext. 121 214-869-8912 cell 972-864-2334 fax ________________________________ From: chaucer chern [mailto:chaucerdesign@gmail.com] Sent: Thursday, April 22, 2010 5:37 PM To: Chris Robinson Cc: Clay Barnett; Ross Harle Subject: Re: revised storm drain, Crown Plaza hi, chris, the inlet on the pronton where the zone 1 originally drain to, has two 10' inlets. i have no info on the line size. clay never get it to me. and there is another 10' inlet on the proton, its about 300' west of this double inlet. i really don't see a problem on its capacity. my read on this is that clay didn't like to change the existing drain pattern. so if we install a new drain system, it will take care of his concern. also caly got a point that the north landing ramps(2) are lower than the grade, and it has a chance to back flow into the building if the line ever get clogged up. this new system, though, will address both issues at owner's additional cost respectfully chaucer On Thu, Apr 22, 2010 at 4:25 PM, Chris Robinson wrote: Chaucer, Have you determined that discharging the roof runoff overland to the inlet in Proton is not an option under the Town’s drainage standards? Chris Robinson, P.E. Grantham & Associates 1919 S. Shiloh Suite #440, LB 8 Garland, TX 75042 972-864-2333 ext. 121 214-869-8912 cell 972-864-2334 fax ________________________________ From: chaucer chern [mailto:chaucerdesign@gmail.com] Sent: Thursday, April 22, 2010 3:42 PM To: Clay Barnett; Chris Robinson; Ross Harle Subject: Re: revised storm drain, Crown Plaza good afternoon, gentlemen after studying your 2nd review, here is my proposal: 1. install a new storm drain system, composed of 24" grate inlet and 15 and 18" RCP, to guide all roof water back to original 10' curb inlet on the midway road. thus we are not changing the original drainage system, and hence, not adding water to the inlet on the proton street. 2. the new storm line has capacity up to 6 cps, and maintain drainage speed 2' per second at 1% or better slope 3. this system drain into existing 10' curb inlet, which connects to city's line on a existing 18" RCP 4. i'll revise the drainage calculation 5. will continue the plan clean ups for better clarity have a great day respectfully chaucer On Wed, Apr 21, 2010 at 3:22 PM, Clay Barnett wrote: Chaucer, Attached are the comments for Crown Plaza. Thanks, Clay Barnett, P.E. Town Engineer Town of Addison 16801 Westgrove Drive Addison, TX 75001-2818 Office: (972) 450-2857 ****************************************************************************************************************** This e-mail and any files or attachments transmitted with it contains Information that is confidential and privileged. This document may contain Protected Health Information (PHI) or other information that is intended only for the use of the individual(s) and entity(ies) to whom it is addressed. If you are the intended recipient, further disclosures are prohibited without proper authorization. If you are not the intended recipient, any disclosure, copying, printing, or use of this information is strictly prohibited and possibly a violation of federal or state law and regulations. If you have received this information in error, please delete it and notify Hamid Khaleghipour at 972-450-2868 immediately. Thank you. *******************************************************************************************************************