Loading...
DR9802-CN 981014Halff Associates tiNt ;INlJ RS; ° .\R('HIT['('I'N · h( IINIINIS~ Iq,.\NNI RS; · SI:R\'I,~ 8616 NORTHWEST PLAZA DRIVE DALLAS TEXAS 75225 (214) 739-0094 FAX (214) 739-0095 October 14, 1998 P9436 WO22 Don Moulton, PE NCH Corporation 2727 Chemsearch Boulevard Irving, Texas 75062 James Witt, City' Manager City ot7 Coppell PO Box 478 255 Parkway Blvd. Coppell, Texas 75019 RE: Drainage Master Plan Study- NCH Site, Coppell Industrial N. V. Site and Related Areas in Coppell, TX Dear Mr. Moulton and Mr. Witt: Halff Associates is pleased to present this fee proposal for engineering services to prepare a Master Drainage Plan for the NCH site, the 100 acre site west of the NCH site owned by Coppell Industrial N. V. and adjoining areas along Bethel Road in Coppell, Texas. This area is located within the drainage basin of Stream Gl. Generally, the setw'ices will consist of conceptual drainage design, stream hydrology and hydraulics as necessary to develop and document a Drainage Master Plan. The entire engineering effort described in this proposal can be completed for a lump sum fee of $45,000. The City of Coppell's share of this fee is $15,000, with NCH and other cooperating land owners responsible for the remaining lump sum fee. Should the study cost exceed $45,000 due to project scope changes and/or additions requested by the property owners, the additional costs will be born by the participating property owners and the City of Coppell's share will remain capped at $15,000. A detailed work plan is attached as Exhibit A and a breakdown of thc engineering fee is included as Exhibit B. Separate invoices will submitted on a monthly basis to the City of Coppell for their portion of the fee and to NCH for the participating property owners portion of thc fee. Invoices will be based on percent complete of the project tasks outlined in Exhibit B. A suggested schedule is shown on Exhibit C. Please call me at 214/346-6220 if you have any questions. We look forward to assisting you and the City of Coppell with this important project. If this proposal meets with your approval, please sign and return one copy to our office to indicate your authorization of the scope of work and fee and our notice to proceed. Counterpart signatures are acceptable. DALLAS · FORTW()RFH · HOUSTON · McALLEN 1 :qANSF'ORT/,TION · WATER RESOURCES · [ AND [3E~EI OPMENT · MUNICIPAL · ENVIRONMENTAL · STRUCTURAL MECHAN 0AL · ELECTRICAL · S~IRVE',ING · GEOGRAPHIC INFORMATION SYSTEMS ARt~;HiTE. CTURE * t AND3C&F[ ARCHITECTURE · PLANNING Bill · .- Halff Associates 1.2N(HNE}-RS · ,,\R('ttlTI,~('TS · S('lt~NTIS']'S PLANNERS · SURVEY()RS NCH Corporation City of Coppell October 14, 1998 Page 2 Sincerely, HALFF ASSOCIATES, INC. Walter E. Skipwith, PE Vice President NCH Corporation APPROVED: BY: DATE: City of Coppell APPROVED: BY: L DATE: · ., Halff Associates l?l PI.ANNI:RS * City of Coppell NCH Corporation October 13, 1998 Page 3 EXHIBIT A Scope of Work Drainage Master Plan Study- NCH Site, Coppell Industrial N. V. Site and Related Areas Along Bethel Road in the Stream G1 Watershed in Coppell, TX I. Data Acquisition/Basemap Preparation A Kickoff meeting B Obtain plans, current zoning, existing landuse from City C Obtain approved site topography and plans from NCH, adjacent sites and City D Obtain and plot City topography E Site visit, including photographs F Merge site plans/topography and city topography to create basemap G Create location map II. Surveys A Miscellaneous surveys of drainage structures in the study area B Extend FEMA benchmark to study area !I1. Drainage & Flood Plain Analysis A 1 2 3 4 5 6 7 8 Hydrology Research effective fully developed (FD) landuse hydrologic model Locate 'best' electronic files in archives, execute, plot Compare 1 and 2 Rcvisc model with added detail in upstream reaches Debug, execute, plot results for 2- & 100-year flood discharges Revise hydrology model for existing landuse Debug, execute, plot results for 2- & 100-year flood discharges Compare computed discharges with previous studies III · -- Halff Associates ENGINEERS · ARCHH'ECTS · SCIENTISTS PL:XNNERS · SURVF?~'()RS City of Coppell NCH Corporation October 13, 1998 Page 4 B 1 2 3 4 5 5 6 C 1 2 3 D Hydraulics Identify effective stream hydraulics model from City Locate 'best' electronic files, execute, plot Compare 1 and 2 Extend existing conditions models per surveys and topographic map Incorporate fully devcloped and existing landuse discharges Execute, debug, plot revised model Compare to existing models - tables of water surface elevations and velocity Mapping Delineate 100-year flood plain based on fully developed landuses in the watershed Delineate subdrainage areas and discharges Add flood plain and baseline drainage information to basemap Mcet with Owner(s) and City IV. Drainage Master Plan A Formulate General Alternatives 1 Establish targets for detention alternative a. Alternative 1- limit mnoffrate from developed sites to predevelopment rates b. Alternative 2- limit runoffrate from developed sites to that from a landuse less intense that industrial (i.e. Single Family Residential) 2 Confirm conventional drainage criteria 3 Evaluate diversion possibilities 4 Evaluate permitting requirements 5 Meet with Owner and City g NCH and Adjoining Coppell Industrial N. V. Site 1 Conceptual design of conventional system 2 Conceptual design of detention alternatives 3 Conceptual design of combination systems 4 Exhibits 5 Cost estimates 6 Assess downstream impacts C Bethel Road Area 1 Conceptual design- conventional Bethel storm sewer 2 Conceptual design of Bethel storm sewer with detention in upstream basin · -- Halff Associates Ill EN(;INEERS · AR('IIITECTS · SCIENTISTS PLANNERS · S[:RVEYORS City of Coppell NCH Corporation October 13, 1998 Page 5 3 4 5 D 1 2 3 4 Exhibits Cost estimates Assess downstream impacts Recommendations Outline preliminary recommendations Internal peer review meeting Finalize recommendations Meet with Owner(s) and City IV. Study Report/Documentation A Report 1 Write report 2 Assemble and bind 10 copies B Compile electronic files of report and exhibits C Deliver reports and electronic files to Owner(s) and City · -- Halff Associates [!N(iINEERS · ARCHITECTS · SCIENTISTS PI.ANNERS · SI~RVI?/ORS City of Coppell NCH Corporation October 13, 1998 Page 6 EXHIBIT B Fee Breakdown Drainage Master Plan Study- NCH Site, Coppell Industrial N. V. Site and Related Areas Along Bethel Road in the Stream G1 Watershed in Coppell, TX Task Fee Breakdown I. Data Acquisition/Base Map Preparation II. Surveys III. Drainage and Flood Plain Analysis IV. Drainage Master Plan V. Study Report/Documentation $ 3,486 $ 1,850 $ 16,145 $ 19,118 $ 4,401 Lump Sum Total $ 45,000 Halff Associates }iN(;1Nt~ERS · AR('HITECTS · SCIENTISTS PLANNI~RS · SURVISYORS City of Coppell NCH Corporation October 13, 1998 Page 7 EXHIBIT C Schedule Drainage Master Plan Study- NCH Site, Coppell Industrial N. V. Site and Related Areas Along Bethel Road in the Stream G1 Watershed in Coppell, TX Task Notice to Proceed Kickoff Meeting Data Collection Survey Drainage and Flood Plain Analysis Drainage Master Plan Report Completion Date 10/25/98 10/26/98 10/28/98 11/09/98 12/09/98 1/21/99 1/28/99 Note: Schedule is flexible and can be adjusted within reason to meet the needs of the study participants Halff Associa F~NGINF. ERS - \I~.CHITECTS · SCIENTISTS PI.,\NNI~RS · [es 36!6 NORTHWEST PLAZA DRIVE DALLAS, TEXAS 75225 i214~ 739-0094 FAX ~214) 739-0095 October 14, 1998 P9436 WO22 Don Moulton, PE NCH Corporation 2727 Chemsearch Boulevard Irving, Texas 75062 James Witt, City Manager City of Coppell PO Box 478 255 Parkway Blvd. Coppell, Texas 75019 Drainage Master Plan Study- NCH Site, Coppell Industrial N. V. Site and Related Areas in Coppell, TX Dear Mr. Moulton and Mr. Witt: Halff Associates is pleased to present this fee proposal for engineering services to prepare a Master Drainage Plan for the NCH site, the 100 acre site west of the NCH site owned by Coppell Industrial N. V. and adjoining areas along Bethel Road in Coppell, Texas. This area is located xvithin the drainage basin of Stream Gl. Generally, the services will consist of conceptual drainage design, stream hydrology and hydraulics as necessary to develop and document a Drainage Master Plan. The entire engineering effort described in this proposal can be completed for a lump sum fee of $45,000. The City of Coppell's share of this fee is $15,000, with NCH and other cooperating land owners responsible tbr the remaining lump sum fee. Should the study cost exceed $45,000 due to project scope changes and/or additions requested bv the property owners, the additional costs ~vill be born by the participating property owners and the City of Coppell's share xvill remain capped at $15,000. A detailed work plan is attached as Exhibit A and a breakdown of the engineering fee is included as Exhibit B. Separate invoices will submitted on a monthly basis to the City of Coppell for their portion of the fee and to NCH for the participating property owners portion of the tee. Invoices will be based on percent complete of the project tasks outlined in Exhibit B. A suggested schedule is shown on Exhibit C. Please call me at 214/346-6220 if you have any questions. We look forward to assisting you and the City of Coppell xvith this important project. If this proposal meets with your approval, please sign and return one copy to our office to indicate your authorization of the scope of work and fee and our notice to proceed. Counterpart signatures are acceptable. DALLAS · FORT'NORTH · HOUSTON · McALLEN TRANSPORTATION · WATER RESOURCES · LAND DEVELOPMENT ' MUNICIPAL · ENVIRONMENTAL · STRLJCTURAL ~'IECHANICAL · ELECTRICAL · SURVEYING · GEOGRAPHICIr'qFORMAT~CN S'/STEblS a, RCHITECTURE · LANDSCAPE ARCHITECTURE · PLANNING · I, Halff Associates L:NGINEERS . \RCHITECTS · SCIENTISTS PL,\NNERS · SURVEYORS NCH Corporation City of Coppell October 14, 1998 Page 2 Sincerely, HALFF ASSOCIATES, INC. Walter E. Skipwith, PE Vice President DATE: ,_ City of Copper APPROVED: BY: DATE: Halff Associates ENGINEERS · .\RCHITECTS · SCIENTISTS PLANNERS · 5~ RVEYORS City of Coppell NCH Corporation October 13, 1998 Page 3 EXHIBIT A Scope of Work Drainage Master Plan Study- NCH Site, Coppell Industrial N. V. Site and Related Areas Along Bethel Road in the Stream G1 Watershed in Coppell, TX I. Data Acquisition/Basemap Preparation A B C D E F G Kicko fi' meeting Obtain plans, current zoning, existing landuse from City Obtain approved site topography and plans from NCH, adjacent sites and City Obtain and plot City topography Site visit, including photographs Merge site plans/topography and city topography to create basemap Create location map II. Surveys A B Miscellaneous surveys of drainage structures in the study area Extend FEMA benchmark to study area III. Drainage & Flood Plain Analysis A 1 3 4 5 6 7 8 Hydrology Research effective fully developed (FD) landuse hydrologic model Locate 'best' electronic files in archives, execute, plot Compare l and 2 Revise model xvith added detail in upstream reaches Debug, execute, plot results t~or 2- & 100-year flood discharges Revise hydrology model for existing landuse Debug, execute, plot results t'or 2- & 100-year flood discharges Compare computed discharges with previous studies Halff Associates ENGINEERS · -\RCItlTt!CTS - SCIENTISTS PL,\NNERS · St ItVEYORS City of Coppell NCH Corporation October 13, 1998 Page 4 B Hydraulics 1 Identify effective stream hydraulics model from City 2 Locate 'best' electronic fides, execute, plot 3 Compare 1 and 2 4 Extend existing conditions models per surveys and topographic map 5 Incorporate fully developed and existing landuse discharges 5 Execute, debug, plot revised model 6 Compare to existing models - tables of water surface elevations and velocity C Mapping 1 Delineate 100-year flood plain based on fully developed landuses in the watershed 2 Delineate subdrainage areas and discharges 3 Add flood plain and baseline drainage information to basemap D Meet with Owner(s) and City IV. Drainage Master Plan A 1 5 B 1 3 5 6 C 1 Formulate General Alternatives Establish targets for detention alternative a. Alternative 1- limit runoff rate from developed sites to predevelopment rates b. Alternative 2- limit runoff rate from developed sites to that from a landuse less intense that industrial (i.e. Single Family Residential) Confirm conventional drainage criteria Evaluate diversion possibilities Evaluate permitting requirements Meet ~vith Owner and City NCH and Adjoining Coppell Industrial N. V. Site Conceptual design of conventional system Conceptual design of detention alternatives Conceptual design of combination systems Exhibits Cost estimates Assess downstream impacts Bethel Road Area Conceptual design- conventional Bethel storm sewer Conceptual design of Bethel storm sewer ~vith detention in upstream basin Halff Associates ENGINEERS · ~XRCHITECTS · SCIENTISTS PI.,\NNERS · SUR\,'E'f()RS City of Coppell NCH Corporation October 13, 1998 Page 5 3 Exhibits 4 Cost estimates 5 Assess downstream impacts D Recommendations 1 Outline preliminary recommendations 2 Internal peer review meeting 3 Finalize recommendations 4 Meet with Owner(s) and City IV. Study Report/Documentation A 1 2 B C Report Write report Assemble and bind 10 copies Compile electronic files of report and exhibits Deliver reports and electronic files to Owner(s) and City Halff Associates ENGINEERS · ..\RCIflTECTS - SCIENTISTS PLANNERS · StiR\"EYORS City of Coppell NCH Corporation October 13, 1998 Page 6 EXHIBIT B Fee Breakdown Drainage Master Plan Study- NCH Site, Coppell Industrial N. V. Site and Related Areas Along Bethel Road in the Stream G1 Watershed in Coppell, TX Task Fee Breakdo~vn I. Data Acquisition/Base Map Preparation II. Surveys III. Drainage and Flood Plain Analysis IV. Drainage Master Plan V. Study Report/Documentation $ 3,486 $ 1,850 $ 16,145 $ 19,118 $ 4,401 Lump Sum Total $ 45,000 Halff Associates ENGINEERS · \RCHITECTS · SCIENTISTS PL,\NNERS · SURVEYORS City of Coppetl NCH Corporation October 13, 1998 Page 7 EXHIBIT C Schedule Drainage Master Plan Study- NCH Site, Coppell Industrial N. V. Site and Related Areas Along Bethel Road in the Stream G1 Watershed in Coppell, TX Task Notice to Proceed Kickoff Meeting Data Collection Survey Drainage and Flood Plain Analysis Drainage Master Plan Report Completion Date 1 O/25/98 1 O/26/98 10/28/98 11/09/98 12/09/98 1/21/99 1/28/99 Note: Schedule is flexible and can be adjusted within reason to meet the needs of the study participants