Could we meet out there?
Clay Barnett, P.E.
Town Engineer
Town of Addison
16801 Westgrove Drive
Addison, TX 75001-2818
Office: (972) 450-2857
From: Nancy Cline
Sent: Wednesday, August 25, 2010 9:56 AM
To: 'ELittle@udr.com'; Clay Barnett
Cc: 'blafoy@ndmce.com'; 'brusk@ndmce.com'
Subject: Re: Vitruvian Channel Section
Eric,
Would you please update me on the status of the creek excavation? After we talked yesterday, I started to think it seems this contractor is not anticipating the work requirements. Please
let me know what the plan is. I am not comfortable with their experience at this time.
Thank you,
Nancy
________________________________
From: Eric T. Little
To: Nancy Cline; 'Bruce Dunne' ; Clay Barnett; Joel Massey ; Tom Lamberth
Cc: Brian J. LaFoy ; Brad Rusk ; Nick Jacob
Sent: Mon Aug 23 16:20:12 2010
Subject: RE: Vitruvian Channel Section
All,
We are out of time here. This work was supposed to begin tomorrow, but without knowing what we are supposed to do on the creek bottom, it’s almost impossible to move forward.
I’m going to instruct them to go ahead and start 3’ in and then cut to a 10:1 V. If we change it will be easier to cut down to a 3:1. Also need to know what we are supposed to do for
the recirc pump at the existing weir.
Need help here please.
Eric Little
Project Manager, UDR
5430 LBJ Freeway, Suite 1250
Dallas, TX 75240
Ph: 972.774.0552
Fx: 972.991.4113
Cell: 214.641.5761
www.UDR.com
From: Nancy Cline [mailto:ncline@addisontx.gov]
Sent: Monday, August 23, 2010 10:44 AM
To: 'Bruce Dunne'; Eric T. Little; Clay Barnett; Joel Massey
Cc: Brian J. LaFoy; Brad Rusk
Subject: RE: Vitruvian Channel Section
Last week I requested cross sections at 50 ft intervals. Would you please send these as I requested?
Nancy Cline
From: Bruce Dunne [mailto:bdunne@icon-engineers.com]
Sent: Monday, August 23, 2010 10:42 AM
To: Eric T. Little; Clay Barnett; Joel Massey; Nancy Cline
Cc: Brian J. LaFoy; Brad Rusk
Subject: RE: Vitruvian Channel Section
The proposed cross section change, as submitted to the Town last week for the area of the creek south of the Ponte Avenue bridge to the existing weir structure, will result in a miniscule
increase in velocity in this area of the creek. The cross section of the creek would decrease by 12 square feet. The average area of flow in this area was originally proposed to be
1150 square feet, so theoretically this area would be decreased to an average of 1138 square feet, resulting in an increase in velocity from around 7.80 feet per second to 7.88 feet
per second. If this is unacceptable to the Town, I would suggest we go back to the original cross section proposed on the drawings. After seeing the creek last week with the water
drained out, I feel the section as originally designed will work just fine.
From: Eric T. Little [mailto:ELittle@udr.com]
Sent: Monday, August 23, 2010 9:56 AM
To: Clay Barnett; Bruce Dunne; Joel Massey; Nancy Cline
Cc: Brian J. LaFoy; 'Brad Rusk'
Subject: FW: Vitruvian Channel Section
All,
Mr. Wallace has reviewed the new cross section and he is concerned that we are going to end up increasing the velocity of the creek by changing from a 10:1 to a 3:1 in the channel bottom.
We need direction on this ASAP as they are scheduled to start grading tomorrow.
Thanks,
Eric Little
Project Manager, UDR
5430 LBJ Freeway, Suite 1250
Dallas, TX 75240
Ph: 972.774.0552
Fx: 972.991.4113
Cell: 214.641.5761
www.UDR.com
From: Brian J. LaFoy [mailto:blafoy@ndmce.com]
Sent: Monday, August 23, 2010 9:51 AM
To: Eric T. Little
Cc: 'Brad Rusk'; William L. Wallace
Subject: FW: Vitruvian Channel Section
Eric:
I was on vacation last week but reviewed Brad and Bill's response on the downstream channel work this morning. See below for NDMs response.
Brian J. LaFoy, P.E.
Vice President
Nathan D. Maier Consulting Engineers, Inc.
8080 Park Lane, Suite 600
Dallas, Texas 75231
Ph. 214-739-4741 / Fax 214-739-5961
blafoy@ndmce.com
________________________________
From: Brad Rusk [mailto:brusk@ndmce.com]
Sent: Friday, August 20, 2010 8:51 AM
To: blafoy@ndmce.com
Subject: FW: Vitruvian Channel Section
Brian,
Bill's response below regarding the proposed revised channel section for Vitruvian south of the Ponte bridge.
Brad Rusk CPC, CCCA
Construction Manager
Nathan D. Maier Consulting Engineers, Inc.
8080 Park Lane, Suite 600
Dallas, TX 75231
ph. 214.739.4741
fax 214.739.5961
-----Original Message-----
From: William L. Wallace [mailto:bwallace@ndmce.com]
Sent: Friday, August 20, 2010 8:39 AM
To: Brad Rusk
Subject: Vitruvian Channel Section
Brad, You asked me to review the proposed cross-section for the channel grading downstream of the Ponte Bridge. I had two initial concerns: did it meet the intent of the 404 permit
and was it consistent with the hydraulic model. I looked at both issues.
404 Permit - Ex. 10, Fig. 2 shows the proposed general section in this area. Although the proposed section is not the same, they both show grading in the channel. For purposes of the
404 permit, I believe they both show similar intents.
Hydraulic Model - There are two sections in the model in this area.
Section 6.272 and 6.303. Section 6.272 is the more critical because there are high channel velocities at this natural creek section. The proposed section is not consistent with the
hydraulic model. The proposed section is deeper and with steeper bottom cross-slopes. The hydraulic model shows approximate 10:1 slopes versus the new section has a 3' bench area and
3:1 slopes. To get an idea of the possible impacts I revised the HEC-2 model to more closely represent the new proposed section. Revising the section had 2 impacts. Generally the
water surface elevation increased by about
0.1 feet. This increase did not extend upstream into the area where there were increases over existing conditions. The change did increase the channel velocities. The following summarizes
the velocities at Section
6.272
Corrected Existing = 8.6 fps
Previous Proposed = 9.2 fps
Revised Proposed = 9.6 fps
I remain concerned about the channel velocities in this area and do not recommend sections that result in additional increases to the velocity in this sensitive area. Let me know if
you have questions concerning this.
Thanks Bill
William L. Wallace, P.E.
Executive Vice President
Nathan D. Maier Consulting Engineers, Inc.
8080 Park Lane, Suite #600
Dallas, TX 75231
PH: (214)-739-4741
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