Jeff,

 

            I brought my copy of the plans for the forthcoming airport improvements by your facility and left it at your front desk. Please let me know if you did NOT receive it. Also,
I would like to get it back after your engineer is through looking at it, but he is welcome to take as much time with it as he needs.  I think the main benefit for Million Air may be
to get a look at the plans for filling in the ditch on the north side of your ramp. Our engineer (Garver) has designed that part of the project on the assumption that when we are finished
with construction there, you will probably want to lease that area and expand your ramp. With this in mind, they made allowances for the drainage for paving most of that triangular area
that is north of your ramp, where the ditch is now. Garver was really on the ball, because they did that without us even having to ask for it. They are well aware of the difficult drainage
issues on this airport.

 

            Even so, I don’t really see how having these drawings to look at will help with your current problems with the drainage from the site of the new facility on Taxiway Victor.
 Our engineer has taken a preliminary look at the drainage on Taxiway Victor – as previously mentioned, we have a TX-DOT and FAA-funded project to improve the drainage on Taxiways Uniform
and Victor with construction planned for FY14 – and it is already going to be very challenging for them to design drainage in that area that will comply with the city’s codes.  The primary
goal of those drainage improvements on Uniform and Victor will be to bring the taxiway safety areas into compliance with FAA standards for drainage and grading. That will require us
to get rid of the bar ditches, and it would also preclude any type of open detention ponds in those areas. That is one of the major problems we are correcting in the current project
with the drainage along Taxiway Alpha right by the inlet to your ramp.  Most of the large, high-value aircraft are at that end of the airport, going in and out of your ramp and the hangars
on Taxiway Victor. If an aircraft were to slide off the taxiway, a proper safety area will greatly reduce the potential for damage. If we have bar ditches and drain inlets that are too
far below grade (as we do now) and an airplane goes into that, we are probably going to need a crane to get it back out. Those are the problems the airport is trying to correct, and
I don’t think open detention next to a taxiway (in the taxiway safety area) would be a defensible thing to permit.  If we could get it far enough away from the taxiway that it would
be out of the safety area, my guess is that would be acceptable, but that would put it on your leased area.

 

            I still think you have a few options to consider that would be cheaper than underground detention. Your engineer may wind up having to use some combination of ideas, and
I know the Town’s engineer has already been working with him to try to find a solution that will meet the requirements of the ordinance. Since you will be reconfiguring at least part
of your parking lots, maybe using porous asphalt pavement for the automobile parking lots would help? My guess is that by reducing the runoff from your automobile parking areas, you
could accommodate that much more runoff from the ramp.  Also, setting the building back from Westgrove just a few feet would give that much more additional detention volume out front.
And the drawings I saw showed a circular feature in the parking area that might be turned into a detention area?  Not being a civil engineer, I’m just throwing out ideas that I think
may be worth considering … I don’t know whether they would be cost effective, but the engineers could certainly figure that out.

 

            I’ll do whatever I can to assist, but I can’t make the requirements of the ordinance go away and I don’t believe the Public Works engineers can do that either. I know we
are all willing to work with your team to help find a solution that meets both your operational and aesthetic requirements as well as the standards of the ordinance. However, I don’t
think putting a significant amount of the drainage down Taxiway Victor is going to work, because (as I understand it) any increase in the peak run-off that is already in that bar ditch
would not be in compliance with the ordinance. Whatever is acceptable to the Public Works engineers is acceptable to me, and if there is anything more I can do to facilitate getting
to a solution please let me know.  We all want to see this project succeed.

 

Best Regards,

 

Joel

 

 

Joel Jenkinson

Director, Addison Airport

  main: (972) 392-4850

  fax: (972) 788-9334