RE: CRS Activity 450 SMR (3)Dave,
I apologize for not getting back to you sooner. We have been very busy with all the rain we have had down here. Im not sure if this is what you are looking for but this is what we have
and what we do. Our requirement is any and all new developments are required to meet the criteria of designing for the fully developed 100 year storm event. We ask that they show
on their plans that the existing storm drain system they are tying into has the capacity to accommodate the 100 year fully developed storm event from their site. If it does not then
they are required to detain onsite. We do not ask for a drainage report, it is just shown on their plans. The only time we ask for a report is when they do a CLOMR, and we require no
rise in the water surface elevation of fully developed 100-year floodplain.
Please let me know if you need anything else.
Thanks,
Mike
From: Dave Carlton [mailto:dave@dkcarlton.com]
Sent: Tuesday, May 26, 2015 3:51 PM
To: Michael Garza
Cc: Deidra Mares (dmares@iso.com); Kyra Jansen
Subject: RE: CRS Activity 450 SMR
Thanks Michael. The Design Manual helps to clarify the design storms used. From what I have I’m unable to determine to what size of development these standards would apply. For instance
– single family residence on an existing lot, new subdivision, any development creating 10,000 sf of new impervious surface, any new development of 5 acres or greater. Do you have such
a standard and where would I find it?
Also, I’m going to need five examples of how new development met the criteria. Typically this would be contained in a drainage report submitted by the developer. I don’t need the models
or the plan sheets, but rather the text describing the development and showing that the post development 5-year and 100-year flows meet the criteria.
Thanks for the help.
Dave
Dave Carlton, PE CFM D.WRE
dkcarlton & associates, PLLC
4040 NE 204th ST
Lake Forest Park, WA 98155
206-604-7533
dave@dkcarlton.com <mailto:dave@dkcarlton.com>
From: Michael Garza [mailto:MGarza@coppelltx.gov]
Sent: Tuesday, May 26, 2015 12:29 PM
To: Dave Carlton
Cc: Deidra Mares (dmares@iso.com <mailto:dmares@iso.com> ); Kyra Jansen
Subject: RE: CRS Activity 450 SMR
Dave,
Please see attached dallas design manual. This is what we follow for design. The peak runoff rate from a 5-year event as well as the 100 year event must be held to the pre-development
rate.
Deidra, you should be receive the rest of the requested items within the next day or so.
Let me know if you need anything else.
Thanks,
Michael Garza, P.E.
Assistant Director of Engineering
Engineering Department
City of Coppell, TX
<http://www.coppelltx.gov> www.coppelltx.gov
972-304-7019 (office)
<http://www.coppelltx.gov/>
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cocoppell-522.html>
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From: Dave Carlton [mailto:dave@dkcarlton.com]
Sent: Friday, May 22, 2015 11:18 AM
To: Michael Garza
Cc: Deidra Mares (dmares@iso.com <mailto:dmares@iso.com> ); Kyra Jansen
Subject: RE: CRS Activity 450 SMR
I appreciate the update and next week would be great. Thanks for letting me know.
Dave
Dave Carlton, PE CFM D.WRE
dkcarlton & associates, PLLC
4040 NE 204th ST
Lake Forest Park, WA 98155
206-604-7533
dave@dkcarlton.com <mailto:dave@dkcarlton.com>
From: Michael Garza [mailto:MGarza@coppelltx.gov]
Sent: Friday, May 22, 2015 6:47 AM
To: Dave Carlton
Cc: Deidra Mares (dmares@iso.com <mailto:dmares@iso.com> ); Kyra Jansen
Subject: Re: CRS Activity 450 SMR
I apologize, I am out if the office again this week, I will have everything to you next week after the holiday.
Thanks
Michael Garza, P.E.
Assistant Director of Engineering
City of Coppell
972-304-7019
On May 21, 2015, at 4:59 PM, Dave Carlton <dave@dkcarlton.com <mailto:dave@dkcarlton.com> > wrote:
Hello Michael. I have been reviewing the documentation forwarded to me for Stormwater Management Credit. As you know, credit is dependent upon both the size of development regulated
and the design storm(s) used. Your March 19 email to her states the design storm can be found on page V-1 of the stormwater management study. That page only discusses Floodway Capacity
and Channelization issues, not design storm for control of excess runoff from new development. What we are looking for are not design standards for conveyance facilities, but rather
to what standard due you require new development to match the pre-developed flows from the site. For instance, are they required to release the flows from a 10-year storm at no greater
rate than existed prior to development? I could find no such standard on your website or in the documents that were sent to me.
You also mentioned that the you follow the Dallas Design Manual. I do not have a copy of the manual to review. Do you know if it is online?
Thanks for your help.
Dave
Dave Carlton, PE CFM D.WRE
dkcarlton & associates, PLLC
4040 NE 204th ST
Lake Forest Park, WA 98155
206-604-7533
dave@dkcarlton.com <mailto:dave@dkcarlton.com>