DR9601-CS 960723OEM Halff Associates
ENGINEERS • ARCHITECTS • SCIENTISTS
PLANNERS• SURVEYORS
City of Coppell
255 Parkway Blvd.
Coppell, TX 75019
ATTN: Mr. Michael A. Martin
RE: Lot 3, Block 2, Gateway Business Park
Drainage Improvements
Dear Mr. Martin:
8616 NORTHWEST PLAZA DRIVE
DALLAS, TEXAS 75225
(214) 739 -0094
FAX (214) 739 -0095
July 23, 1996
AVO 15539
On behalf of Catellus Development Corporation we are submitting for your review and
approval an estimate for the cost of constructing and maintaining the permanent erosion control system
for the offsite ditch for a two -year period. The three permanent erosion control systems are the rock rip -
rap for the 60 -inch RCP, the erosion control blanket and grassing; Since the grass after being established
is non irrigated, the only maintenance required consists of mowing. Mowing will be required at least
once a month, four months out of the year, for two years.
Initial Cost of Construction
• Permanent Grassing, complete in place (1LS) $14,550
• Rock Rip -Rap (475 SY) $28,500
• Erosion Control Blanket (4,000 SY) $6,200
• SUBTOTAL $49,250
Maintenance Cost:
• Channel Mowing (8 times @ $500 each) $2,000
• SUBTOTAL $2,000
Total Cost (Initial + Maintenance) $51,25 0
If you have any questions or need any additional information, please do not hesitate to call
either Pat Acker or myself.
Sincerely,
HALFF ASSOCIATES, INC.
M. Cristina Gonzalez - Criado, E.I.T.
cc: Steve BrianA Steve Williamson, Catellus Development Corporation.
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