PA9702-CS 970307P.O. Box 478
Coppell, Texas 75019
214-462-0022
March 7, 1997
Bennett Ratliff, P.E.
Jones & Carter, Inc.
12000 Ford Road, Suite 180
Dallas, Texas 75234
RE: Proposed recreational sites
Dear Mr. Ratlift:
This letter is written as a follow-up to our telephone conversation concerning the proposed
recreational sites on MacArthur B!vd. and Andrew Brown Park East. You requested a
letter indicating the floodplain status of these two sites. As stated in our telephone
conversation, both sites contain floodplain in the vicinity of the proposed structure. I have
attempted to generally draw the location of the floodplain boundaries on the two exhibits
provided to me. The following represents a more detailed discussion of each of the sites in
regard to floodplain.
MacArthur Site:
The MacArthur site has two concerns. One concern is the floodplain and the other is the
requirement for a Corridor Devdopment Certificate. As you are aware, the floodplain cuts
along the southern edge of the proposed building into the proposed pool area and aCross
the parking on the east side of the facility. It is my understanding during our conversations
that if this site is selected, the low area will be replaced by a culvert to eliminate the
floodplain. As I have stated, simply ~ling the area does not necessarily remove it from the
floodplain. The floodplain area in question is an area of storage not an area of conveyance.
If the MacArthur site is chosen, I would be happy to visit with FEMA representatives in
Denton to determine what options are available to the City to remove this area from the
floodplain, short of performing a detailed flood analysis study. It is my hope that FEMA
would use some logic in assisting the City in removing a small sliver of storage that has no
impact on the overall floodplain within the City of Coppelt or the Elm Fork of the Trinity
River.
The second issue associated with the MacArthur site is the Corridor Development
Certificate (CDC). This is a program developed by the Council of Governments in
conjunction with nine cities, three counties and several agencies. It is an attempt to have
each of the cities affected by the Trinity River to more dosely monitor development within
the Trinity River basin. Upon review of the maps, I noticed a small portion of the east side
of this site is contained within what is classified as a review zone. The review zone does not
require a detailed hydraulic unaiysis but only a Notice of Intent. The Notice of Intent is
a simple two page informational sheet describing what will take place on the property. As
a further note, the review area appears to be contained in what was originally the
Riverchase Reclamation Project. The Riverchase Reclamation Project was "grandfathered"
when the CDC process was adopted. Therefore, I will take the position on the MacArthur
site that the Notice of Intent will need to be completed and provided to this office but it will
not be processed to the other entities for comments.
Andrew Brown East (Central) Park Site:
The location of the facility is generally north and west of the Kid Kountry development.
I reviewed the floodplain on this site from two different approaches. The first approach
was to transpose the lines as shown on the official floodplain map onto the exhibit provided
to this office. In doing that, it appears as though about 40 feet on the northwest corner of
the proposed facility is contained within the floodplain and approximately 60% of the
proposed outdoor pool is contained within the floodplain. In cross checking some of the
locations of the streets on the official floodplain map, it appears as though there could be
some discrepancies. However, FEMA is very precise in the fact that pictorial
representation on the floodplain map is the actual location of the floodplain. Based on the
configuration of the structure, it appears that it could be oriented sllgh~y different to
remove it from the floodplain. The pool could present a problem being in the floodplaln
because of tl~e requirement of a fence for safety reasons.
Because of a slight discrepancy in some of the street locations on the floodplain map, I also
determined the floodplain based on elevation. The 100-year floodplain elevation in this area
is approximately 456.3. This information was obtained not only from the floodplain map
but from the hydraulic study performed in 1992 on Andrew Brown Park. After
transposing that elevation onto the exhibit, it appears that the northern corner of the
proposed facility is still within the floodplain. Also, approximately 60 to 70 percent of the
outdoor pool area is within the floodplain. I've shown the general locations of those
floodplains on the exhibit provided.
To construct the facility on Andrew Brown Park as shown, a modification of the floodplain
study will be required. My recommendation is to orient the structure so that it is not
within the floodplain either by pictorial representation or by elevation. Hydraulic
information should then be provided to the City showing that the construction of the
outdoor pool and fencing will not have an adverse impact on the water surface. My
concern is to ensure that we do not construct something in the floodplain that would have
an adverse impact on existing homes in the Stonemeade subdivision. If the above can be
accomplished, then the City Council could consider a variance to the Floodplaln Ordinance
to allow the outdoor swimming pool and fencing to be contained within the floodplain.
However, it is very important that the structure itself not be located within the floodplain.
I hope this discussion has adequately answered the concerns about the floodplain associated
with these two sites. It is my opinion that neither site has a significant impact to water
surface elevations of the lO0-year floodplain. However, both sites do present challenges
that would need to be addressed before construction could commence. If additional
assistance is required from this depaviment such as contacting FEMA directly on either site,
please feel free to contact me.
Sincerely,
Kenneth M. Griff'm, P.E.
Director of Engineering and Public Works
Certified Floodplain Admini.~trator
cc: Clay Phillips, Deputy City Manager
~le/kgrif~n/parksite.597