Wellington Place-CS 910123RE: Wellington Place Apartments Flooding [ ......
TO: Shohre Daneshmand, P.E., City of Coppell/10751 Files
FROM: Walter Skipwith
Albert H. Halff Associates, Inc.
The Wellington Place Apartments were flooded in the May 1990 flood on the
Elm Fork-Trinity River. Personnel from Halff Associates visited the site on two occasions
during the event and photos were taken. The depth of flooding inside the apartments was
estimated at I to 2 feet. A high water mark for this flood event was recorded near the
apartments. The elevation of this high water mark was 446.1 and was based on a nearby
benchmark set by another engineering consultant. All of these elevations and depths are
estimated and should be confirmed by field surveys based on known accurate benchmarks.
A review of the Wellington Place Grading and Drainage plans (by McNamara
Engineering Co. dated December 85) indicate minimum first floor elevations for the
apartments at 445.5 (Sheet C1). The apartments are apparently constructed lower than this
plan elevation if the high water mark and estimated inundation depths are accurate. The
plans also indicate 100 year (ultimate) water surface elevations of 446.3. The apartments
and large portions of the site were apparently designed to be within the 100-year flood plain.
The most recent Corps of Engineer 100-year flood elevation estimated in this area is
approximately elevation 445.
Other construction in the area includes the Riverchase Flood Plain
Reclamation and the Corners of Coppell Shopping Center. The shopping center has a
minimum first floor elevation of 448 based on plans. The apparent minimum fill elevation
for Riverchase adjacent to the Wellington Apartments is 445 based on as built topography
found in city files.
The majority of the Elm Fork flood plain within the City of Coppell has been
reclaimed. Remaining flood plain areas are in recreational use (Riverchase Golf Course).
The Wellington Apartments are flooded by backwater flooding from the Elm Fork 100-year
flood. Because of the extensive existing reclamation, it is not recommended that the City
of Coppell make improvements along the Elm Fork to eliminate the flooding of these
apartments or any other developments in this area. The Fort Worth District, Corps of
Engineers (FWD-COE) has flood control studies underway in the Upper Trinity River Basin.
The Corps of Engineers has just completed a Upper Trinity River Basin Flood Control
Reconnaissance Study. However, none of the alternatives proposed in the Reconnaissance
Study will eliminate the flooding of the apartments. The City of Coppell should request the
COE-FWD investigate this flooding in their ongoing Trinity River feasibility study. On site
protection from Elm Fork flooding could be achieved by some combination of flood walls
or berms, sluice gates and a pump station. These types of improvements should be
constructed by the owners of the apartment complex. The owners and renters within the
apartment complex should be advised to immediately purchase flood insurance to protect
against loss.