Understood. 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 On Aug 16, 2011, at 2:45 PM, Nick Jacob wrote: Please proceed with looking into this issue and offer us 2 or 3 solutions. As previously discussed not only do we need a solution but we need something that will be aesthetically pleasing also. Thanks, Nick Jacob From: Brian J. LaFoy [mailto:blafoy@ndmce.com] Sent: Tuesday, August 16, 2011 2:20 PM To: 'Clay Barnett' Cc: Nick Jacob; 'William L. Wallace'; 'Brad Rusk' Subject: RE: Erosion Solution Nick: We're on your nickel. Do you want me to look into a couple options and present them to you and the Town as an exhibit or some format like that? 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: Clay Barnett [mailto:cbarnett@addisontx.gov] Sent: Tuesday, August 16, 2011 11:44 AM To: 'Brian J. LaFoy' Cc: 'Nick Jacob'; 'William L. Wallace'; 'Brad Rusk' Subject: RE: Erosion Solution Brian, In looking at it after the recent rain, I do not think the “do nothing” approach will be feasible long term. I am open to any solutions that you have in mind as long as they do not damage the pecan tree on the east bank. I do not think that the slope can be cut back on the west bank either because someone when and put up a building in close proximity, but there are no existing trees to deal with. I think some kind of structural solution is in order, but am curious what you would recommend. Thanks, Clay Barnett, P.E. Town Engineer Town of Addison 16801 Westgrove Drive Addison, TX 75001-2818 Office: (972) 450-2857 From: Brian J. LaFoy [mailto:blafoy@ndmce.com] Sent: Tuesday, August 16, 2011 11:25 AM To: Clay Barnett Cc: 'Nick Jacob'; 'William L. Wallace'; 'Brad Rusk' Subject: RE: Erosion Solution Clay: We have quite a bit of experience using ACB. It works fine when used in the right application. I suspect they have a block that would work with the shear forces due to the stream velocities in the creek (they come in different sizes and shapes), but my thought is that is may be difficult to anchor the ends of the ACB mat. You typically can't anchor them at 90 degrees - they anchor radially, which could be a problem as far as space. If you go with the open cell, the vegetation may or may not take. I've seen both situations. I think the cleanest solution would be to turn the end of the boulders back into the slope and then use geomat or rock riprap. But I understand that rock riprap may not be desireable aesthetically. But I don't think it would look any worse than rock rip rap. Flattening the slope might help as well. Has that been explored? We can look at a formal solution if you would like us to do so. Just let me know. 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: Clay Barnett [mailto:cbarnett@addisontx.gov] Sent: Monday, August 15, 2011 3:13 PM To: 'Bruce Dunne' Cc: 'Nick Jacob'; 'Joel Massey'; 'Brian J. LaFoy' Subject: Erosion Solution Bruce, Attached is an article in CE News about a Contech product that could be a possible solution for erosion just downstream of the limestone boulders. I am open to other solutions as well, but I do think we need something to transition from the limestone boulders to the natural turf. Please have look at it and let me know what you think. 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 contain 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. ************************************************************