DUD 10-11AG110613MEMORANDUM
TO: Mayor and City Council
VIA: Kenneth M. Griffin, P.E., Director of Engineering/Public Works
FROM: Michael Garza, ELT, Graduate Engineer
DATE: June 14, 2011
REF: Discussion concerning Creek maintenance
Coppell has four major creeks which flow through or adjacent to the city. These creeks are Denton
Creek, Grapevine Creek, Cottonwood Creek and the Elm Fork of the Trinity River. Also, there are
numerous small creeks which meander through neighborhoods and eventually join with the major
creeks.
According to the City of Coppell's Floodplain Management Ordinance, the City of Coppell has a
responsibility to "promote the public health, safety and general welfare, and to minimize public and
private losses due to flood conditions in specific areas by managing the floodplains of the City." A
flood can be a result of obstructions in areas of special flood hazards which increase flood heights
and velocities. Trees that fall into a creek become obstructions that can cause flooding. Currently,
the Engineering Department has a contract to remove trees that pose a threat to the conveyance of
the creek and possible flooding. This satisfies the FEMA National Flood Insurance Program
Conummity Rating System, which states that the "community should conduct periodic drainage
channel inspections and removed debris as needed to prevent flooding."
To help alert future homeowners of their responsibility when purchasing a creek lot, two notes are
placed on final plats: 1) "The City of Coppell will not have the responsibility for maintenance of
floodplain/floodway area as shown hereon. The maintenance of these areas shall be the sole
responsibility of the individual lot owners adjacent to said areas. These areas are to remain free of
improvements that may obstruct the flow of storm water and protected from potential erosion by the
owners. No fences will be allowed in the floodplain or any other structures (pool, deck, gazebos,
etc.) per the City of Coppell floodplain ordinance," and, 2) "The developer, builder, seller, or agent
shall infonn in writing, each prospective buyer of subdivision lots or property located within special
flood hazard areas of this site that such property is in an identified flood hazard area and that all
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development must conform to the provisions of the City of Coppell Floodplain Management
Ordinance. "
Since the early 90's, we have received calls regarding erosion along creeks in the back yards of
residences. Recently, the majority of the calls have concerned erosion along Denton Creek.
Generally, the property lines of creek lots extend to the center of the creek; therefore the
homeowners are responsible for the maintenance of the bank of the creek. We assist homeowners
that have experienced erosion by providing contact information for engineering fines and
contractors that would be able to repair the erosion.
As previously stated, the City's current creek maintenance program consists of large tree removal
from creeks where the tree is impeding the conveyance of water. This program started several years
ago and is funded through the Municipal Drainage Utility Fund. The program is generally citizen
complaint driven; however, our goal is to become more proactive in the future by walking the
creeks and trying to address some issues before they become major problems.
Staff will be available to answer any questions.
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