TANBARK – STORM WATER DRAINAGE ISSUES/UPDATE (Jan 17, 2016)
HISTORY:
Tanbark Neighborhood is about
30 years old with a few homes older and a few homes newer. Original developers for the five (5) separate
subdivisions within Tanbark Neighborhood worked cooperatively with City/County
officials to adequately and safely deal with storm water runoff, especially to
minimize flooding related to our 140 homes, health care/nursing facility,
church and Racquet Club apartments.
Over
2 miles of curb/gutter collects storm water that reaches the road and thanks to
“gravity” the water flows down and into several cuts in the gutter that allow
the water to then be conveyed underground through concrete pipes ranging from
12” to 24” in the Tanbark area. The
large majority of this collected storm water is then discharged through
approximately a dozen outlet structures located in low laying ditches (or
swales) engineered to then channel the water into ever larger underground pipes
“out of Tanbark” and into local creeks/streams/rivers.
A
goodly portion of these above ground drainage ditches/swales in Tanbark were
lined with concrete, i.e. mostly those on the western half of Tanbark. One of
the major collection ditches/swales responsible for draining about one-third of
our properties on the east side, i.e. 47 homes, lies between Crosby Rd. and the
upper or back portion of Heartland Rd. This
drainage ditch, over 1,000 feet long, collects water draining north to south
from the eastern portion of Tanbark (9 homes), all of Crosby (14 homes), upper
Buttonwood Cr. (5 homes) and the back portion of Heartland Rd. (19 homes). Approximately 26 homes likely have some of
the “far back” yard associated with a storm water easement.
PROBLEM: Some
of the residents of Tanbark have added a few more wrinkles and a little
“sagging” (for some of us) over the last 30 years. Unfortunately, so has the collection
ditch/swale just detailed above. This
collection area did NOT receive a concrete liner; rather an “Environ-net” was
rolled out prior to sowing the area with grass seed similar to that used in our
yards. Unfortunately three major factors
have played a role in today’s problem:
1) “Lawn” grass seed establishes a root system that is
quite shallow….2 to 3” and is therefore susceptible to being washed out during
HEAVY rain events.
2)
Utility
companies (electrical, cable, gas and telephone) have buried lines under this
“more natural” ditch some 1,000 ft (North to South) and crossing under this
area as well (East to West). Over the
past 30 years MANY “digs” have taken place to move/replace/repair/establish
services to the homes on Crosby and Heartwood……each time allowing erosion to
begin in a new area and for soils/debris to be washed down slope to the south.
3)
As Tanbark
has developed so have our lawns, gardens and trees…LOTS of trees with LOTS of
leaves. Unfortunately a goodly portion
of this organic material ends up in our streets, then into the gutters, then
into the underground collection system(s) which then discharges into our lower
backyard(s) or those of our neighbors. For this reason, most know that there is an
ordinance prohibiting blowing grass/leaves other materials into the streets as
the entire waste water collection system is compromised.
Specifically related to the “wrinkles/sagging”
associated with this “more natural” collection ditch the leaves/grass and
sand/dirt (from surface roads) have been deposited at the mouth of each of the
five (5) outlet structures along this ditch.
The end result is the buildup of silt/sands/organics (like a small
Mississippi Delta) for a distance beyond the discharge point(s). Eventually a ponding effect begins as the
silt levels increase. The end result is what we have today: 1) ponding of water after rain events, areas
of poor drainage (especially given the last 2-3 wet years), erosion and
channeling of water moving “too fast” and unfortunately a “fine” area for
mosquito development.
SO WHAT TO DO?? One
of our Crosby residents presented this problem at the Tanbark annual meeting
last January. He was certainly supported
by those present that had property in the near vicinity of this drainage area
given the observed increase in mosquito presence.
To
solve a problem that directly impacts Tanbark residents we need the involvement
and support of all of Tanbark. The last
several years have indicated Tanbark residents firmly support safety and
environmental concerns. We have had
great success with street tree trimming for safety and better vehicle
access. We have installed dozens of
water barrels that allow “natural water” for our plants, but also remove
thousands of gallons of “storm water runoff” that doesn’t enter the storm water
system. And just this past year more
than 1/3rd of our residents stepped up and repaired/replaced hundreds
of concrete sidewalk sections that were a trip hazard for all.
THE PAST YEAR: The Board
feels progress has occurred on many fronts as we have established important
contacts within LFUCG-Division of Water Quality: Charles Martin, Director Dept.
of Environmental Quality & Public Works & Gregory Lubeck, Engineering
Section Manager & Douglas Baldwin, Project Engineering Coordinator. In addition, our 8th District
Councilman, Fred Brown has attended meetings and been most helpful in “moving”
things along. A representative from Time
Warner Cable has not only visited the area……he followed up with some remedial
work that had long been ignored and we “think” we have a good contact for
Windstream. Now we feel we have the beginnings
of a solution based on the following progress and next action(s):
THE PAST YEAR IN DETAIL:
·
January –
Residents in the “ditch area” formally bring the issue to the TAN Board
·
Feb/March –
Shoveled lots of snow and/or dealt w/ lots of rain…..i.e. not much progress
·
April – Many
phone calls/emails attempting to contact to a positive pathway forward
·
April 28th
– A “walk-around” with two employees from Streets/Roads (they indicated our
best/fastest pathway was to involve our councilman, Fred Brown.
·
May 12th
– Letter to Fred Brown (3 pages of history/problem along with 30
photos/exhibits copied to Albert Miller (Director Streets and Roads), David
Holmes (Commissioner of Public Works) along with Windstream and Time Warner
Cable
·
Late May – Brief
meeting to review the problem, the area, maps and path forward with Brown,
Charles Simms and Steve Whyte
·
June 15th
– Formal review/walk around with Charles Simms, Brown and Martin plus Lubeck
from Water Quality. We felt they were
listening and in fact provided information concerning possible grants for
Tanbark as well as indicated they would be working on issues directly related
to the five discharge points.
·
July 14th
– Mr. Lubeck responded:
o
The Incentive Grant applications which will be due in May
2016 are for Fiscal Year 2017 funds. Fiscal Year 2017 will begin July 1,
2016, so if a successful application is made, the work could conceivably begin
in late summer 2016. The outlet pipes
from the streets present a different issue. Without the drainage swale
between the backyards functioning properly, I feel anything done near those
pipes would not be effective. The water would not have a defined path to
take to get away from those pipes, resulting in sediment build up in those
areas again. I’d like to propose hiring a consultant we have on an
indefinite service contract to do some surveying in that area to map what the
existing conditions are. From that, I may be able to come up with some
sort of solution.
·
Aug 8th
– Time Warner Cable representative toured the area and pledged to “immediately”
repair several issues we pointed out to him.
AND HE DID just that as several lines were buried & distribution
boxes repaired.
·
September 1st
– LFUCG kick off meeting related to necessary survey work
·
September 11th
– LFUCG selected Bell Engineering and issued a “Notice to Proceed” within 70
days
·
November 19th
– First Draft completed for LFUCG review.
Doug Baldwin appointed as project manager
·
December 5th
– Second Draft completed
·
December 10th
– LFUCG/Bell met to finalize report/issues
·
December 18th
– Report issued to LFUCG and copied to TAN
·
January 12th
– LFUCG + Bell Engineering + “some” of TAN Board + “some” TAN neighbors met to
review/discuss the report, ask questions, etc.
·
January 17th
– TAN Annual Meeting…………………In Summary
= Decent Progress
NEXT STEPS: Working together LFUCG/Bell Engineering and Tanbark
are “hoping” and planning for construction/repairs late summer or early fall
based on the following:
1)
Bell Engineering presented two options related to
“fixing” the five outfalls within the ditch area to LFUCG. Those present from TAN were pleased with the
selected option (actually the more expensive option) with an estimated cost of
$40,000 (100% LFUCG expense). Use of
concrete interlocking blocks will slow water, retain sediments and yet allow
for relatively simply repair or addition of blocks in the future with very
little expense.
2)
LFUCG would STRONGLY prefer to perform these “fixes”
at the same time the 1,000’ plus drainage swell can be moderately re-graded to
resolve “damning” issues and to fill in eroded channeling. Of course we have tree roots, bushes, utility
lines, etc. to deal with along with selecting the type of grasses/vegetative covers
to re-install in the ditch area that will be much more resistant to erosion in
the future.
a.
The elevation drop from north to south is almost 40
feet, i.e. a 3% grade to keep water flowing.
The LFUCG ‘fix’ related to the five outfalls will maintain at least a 2%
grade away from the structure to prevent ponding.
3)
Updates on progress will be posted on the Tanblogspot
as well as noted in emails and the newsletter.
4)
A TAN committee has been formed to provide
input/oversight and to also contact/explain progress and issues to the
approximate 26 property owners that might border on the storm water easement
area.
5)
Next important date is submission of a grant proposal
in mid-May to cover 80+ percent of repair work in the 1,000 foot drainage
swale.
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