Loading...
Copperstone FS-CS 881014TO dpJerry Parch Consulting Engineers Metro 1817) 572-3458 {817) 56 !-2108 6001 VV. Interstate 20. Suite 209, LB 32. Arlington, Texas 76016 WE ARE SENDING, irate cover via n Shop drawings [] Prints [] Plans [] Copy of letter [] Change order FI [] Samples the following items: [] Specifications COPIES DATE NO. DESCRIPTION THESE ARE TRANSMITrED as checked below: o No ExceptlonsTaken [] For approval [] For your use [] As requested [] For review and comment [] FOR BIDS DUE [] Approved as submitted [] Approved as noted [] Returned for corrections 19 [] Resubmit_ [] Submit [] Return copies for approval copies for distribution corrected prints __ [] PRINTS RETURNED AFTER LOAN TO US REMARKS COPY TO. dP 3erry P arcl & Consulting Engineers October 14, 1988 Mr. Russell ~oyle, P.E. City Engineer City of C~pell P O Boxy8 Coppel~ Texas 75019 214/462-0022 RE: JP No. 88009; Flood Plain Reclamation Study; Parks of Coppell; Coppell, Texas Dear Russell: On Friday, October 7, 1988 we provided two copies of a study entitled "Flood Plain Reclamation Study on Cottonwood Branch and Denton Creek for Construction of Parkway Boulevard and High School Access Road" to the City. Pursuant to our conversation on Wednesday and your letter of October 7, 1988, enclosed herewith is the following additional information that you requested. 1. Another copy of Exhibits A and B. the aforementioned study including e Three copies of the creek cross sections as included in our original submittal that were utilized in the hydraulic analysis. Three separate copies each of Exhibits A and B as included in the folder in the back of the study. In your letter of October 7, 1988, you state that the referenced istudy will be submitted to FEMA on Monday (i.e. October 10, 1988). I inferred from your statements in the first two paragraphs that in the interests of expediting the project, the ~tudy was submitted to FEMA with no prior City review. talSO in your letter you emphasize in the first two paragraphs hat you have assumed that our study complies with all ordinances nd requirements. I can assure you that as engineers for the project our primary concern is to provide a safe design that complies with all City, State and Federal requirements. Following is a brief history of our efforts to understand the City requirements regarding flood plain reclamation in the Parks of Coppell west of Denton Tap Road since our firm was engaged by ABQ Development Corporation to provide engineering services on this project. In addition, in response to your request to submit all information to you regarding the "Grandfathered" status of 6001 bV. Interstate 20, Suite 209, LB 32 * Arlington, Texas 76016 · Metro (817) 572-3458 · (817) 561-2108 Mr. Russell Doyle, P.E. JP No. 88009 October 14, 1988 Page 2 of 4 the Parks of Coppell west of Denton Tap Road, the following documentation is attached for your files and will be referenced in the following discussions. Letter dated May 25, 1988 from Mr. H. Wayne Ginn, P.E., City Engineer of Coppell to Mr. Mike Allen of Univest Development Company wi~.e~.. ~following~ attachments: a. Letter dated Apr$1 4,J 1988 from Mr. Allen to Mr. Ginn. Letter dated November 8, 1982 from Michael Baker, Jr., Inc. to Mayor Andrew Brown, Jr. Ce Letter dated September 24, 1987 from FEMA to Mayor Leu Duggan. d. Letter dated May 3, 1988 from FEMA to Mr. Ginn. A cody of a letter I 1988. sent to Mr. Ginn dated June 8, A copy of a letter I sent to Ms. Maryetta Cunningham of FEMA dated June 17, 1988. A copy of a letter I sent to former flood plain engineer dated June 17, 1988. Mr. Carl for the Anderson, P.E., City of Coppell, A copy of Mr. Ginn's response letter to my June 8, 1988 letter, dated June 21, 1988 with the following attachment: a. Ordinance No. 219 of the City of Coppell, effective June 24, 1980. On June 3, 1988 Mr. Jay Chester of ABQ and I met with Mr. Allen who provided us with the documentation listed under .Item No. 1 above stati~r~yis -exempte~ from the ~i'~6~--~ f the rece 'n Management Ordinance· It is my understanding that Mr. Ginn's letter of May 25, 1988 (Item No. 1) and his signature at the bottom of Mr. Allen's letter of April 14, 1988, (Item No. l-a) confirm this exemption· Having been advised that the Parks of Coppell Property had been exempted from the October 1, 1987 Flood Plain Management Ordinance, I sent a letter to Mr. Ginn dated June 8, 1988 (Item Mr. Russell Doyle, P.E. JP No. 88009 October 14, 1988 PaGe 3 of 4 No. 2) and requested _.~___~ ___he provide m~--a--~et-t~-~s~ating the criteria under which th~ proposed r~clamation project~ will be evaluated by the City. ~ In the meantime, I requested the current effective flood plain models of Denton Creek and Cottonwood Branch through the Parks of Coppell west of Denton Tap Road from FEMA (Item No. 3). For reference purposes, I also requested copies of available flood plain models pr~p-a~d by Mr. Carl Anderson of the City of Coppell ~in my l_~~-~him~f June 17, 1988 (Item No. 4). However, I ~u4~tand that--~Mr. Anderson's models are not currently ~'--~~a~.~s 3ff,ective base flood models by FEMA. ~ ~' obtained Mr. Anderson's flood plain models in a meeting wi~h him on June 22, 1988. Mr. Anderson prepared an extensive study of the City's flood plains including modelling of channel improvements, determination of peak flood discharges for multiple frequency events and determination of the 100-year flood plain with existing channel conditions. His studies did not include / ~--floodway computations or floodway modelling however, to the best of my knowledge. Mr. Ginn provided me a letter dated June 21, 1988, (Item No. 5), responding to my request for direction on preparing the flood plain reclamation study. Since I had previously advised a staff member of Ginn's office that I had already contacted FEMA, the Corps of EnGineers, Mr. Anderson, and several enGineerinG firms with projects in this area, for flood plain data, he felt it best that I obtain computer models of the flood plain from these sources. ReGardinG the criteria or ordinances that will be applied to evaluate our flood plain reclamation study by the City of ~Coppell,~Mr. Ginn provided me. a copy of the City of Coppell Ordinance No. 219 (Item No. 5-a). Section 5.3 of this ordinance is in accordance with FEMA regulations as stated in the National Flood Insurance ProGram and Related Regulations, Part 60, Subpart A, § 60.3. To my knowledge, other areas in the Parks of Coppell and in the VillaGes of Cottonwood Creek were reclaimed in compliance with this regulation. Our study has been prepared in compliance with the provisions of Ordinance No. 219, and Section 5.3 of this ordinance in particular, as directed by Mr. Ginn. ~ ._ ~'~in addition to the correspondance and discussions described above, I have had numerous meetings with other engineers who have prepared studies for projects in this area including Vista RidGe, Century Park, Parks of Coppell, and VillaGes of Cottonwood Creek, as well as with Mr. Anderson on a study he prepared for some _____---proposed Grading work in the City Park. Dewberry and Davis could not provide us current comprehensive effective h~f~lr_aulic models Mr. Russell Doyle, P.E. JP No. 88009 October 14, 1988 PaGe 4 of 4 of Denton Creek and Cottonwood Branch due to the various states of review and approval of the many recent projects in this area. As I discussed with Mr. Chris Ulsch of Dewberry and Davis, we. / ¢ have prepared flood plain models of Denton Creek and Cottonwood V't Branch based on our compilation of the existing computer models prepared for the individual projects that have now been completed in this area. I trust that the information and attachments presented herein have satisfied your request for "grandfathered" documentation and have provided you additional information to evaluate our study. We appreciate your continued cooperation in asistinG us in obtaining necessary City approvals and a Conditional Letter of ~~ap Revision from FEMA. If you need any further information or would like for me to meet with you and discuss these matters, please call. Sincerel~ ! e~rry Parche' , P.E. JP: ch c: Mr. Mr L o'p, /L Jay Chester, P.E./ABQ Development Corporation Wayne Ginn, P.E./Ginn, Inc. P Jerry Parch Consulting Engineers June 8, 1988 Mr. Wayne Ginn, P.E. Flood Plain Administrator City of Coppell 17103 Preston Road, Suite 100 Dallas, Texas 75248 214/248-4900 RE: JP No. 88009; Parks of Coppell; Floodplain Regulations; Coppell, Texas Dear Wayne: On Thursday, June 2, 1988, Mr. Jay Chester of ABQ Development and I met with Mr. Mike Allen of Univest Development Company to discuss several issues related to the future development of the property recently acquired by ABQ in Coppell. This letter is provided to inform you of our discussions with Mr. Allen regarding flood plain regulations of the City applicable to this property and to request additional clarification of the criteria that will be used to evaluate any proposed flood plain modifications within ABQ property west of Denton Tap Road in order that we may prepare our studies in compliance with the requirements of the City. It is my understanding that the property purchased by ABQ Development south of Cottonwood Creek and east of Denton Tap Road, which essentially consists of the Univest property in this area excluding the "Town Center" Tract, or Tract 7, as it is commonly referred to, has been previously reclaimed from the flood plain. Official notification of this is documented in a letter from the Federal Emergency Management Agency to Mayor Lou Duggan of the City of Coppell dated September 24, 1987. Mr. Allen provided us with a copy of this letter. We did not receive a copy of the enclosures however. Mr. Allen also provided us a copy of a letter dated April 14, 1988 from him to you requesting exemption of the unreclaimed portions of the PCJV property from the provisions of the City's recently adopted Flood Plain Management Ordinance. This exemption is pursuant to Section A of Article 3 of this ordinance. By evidence of your signature at the bottom of Mr. Allen's letter, it is our understanding that the City of Coppell has Agreed and Confirmed this exemption. Mr. Allen also provided us a copy of your letter to him dated May 25, 1988, transmitting a letter dated May 3, 1988 from FEMA, which, according to your letter, allows the City of Coppell authority to interpretate its Flood Plain Ordinance without jeopardizing its status in the 6001 Vv'. Interstate 20, Suite 209, LB 32 · Arlington, Texas 76016 · Metro {817J 572-3458 · {817} 561-2108 Mr. Wayne Ginn, P.E. JP No. 88009 June 8, 1988 Page 2 of 3 flood insurance program. Since the proposed flood plain modifications will not be evaluated under provisions of the October 16, 1987 Flood Plain Management Ordinance, I request that you provide a letter to me stating the criteria under which the proposed reclamation and other proposed construction in the flood plain within the exempted property will be evaluated. More specifically we request the following: A. A copy of the HEC II model(s) and output data of Cottonwood Creek and Denton Creek from the downstream side of the Denton Tap Road bridges through ABQ property, and extending upsteam of the ABQ property west of Denton Tap Road. The information should include discharges of multiple frequency floods to be used in our modelling of the proposed improvements and include 100-year flood plain and floodway elevations, as well as 500-year flood elevations, to be used by the City and FEMA in evaluating the hydraulic response of the modified flood plain. ' I understand that several studies have been done on the subject stream reaches including a study by Carter & Burgess in 1982, Threadgill-Dowdey in June, 1987 and Anderson Engineers, Inc. in 1987. By this request, I would like you to clarify for us the hydraulic model that provides the proper base flood conditions that will be used by the City and FEMA to evaluate the proposed flood plain modifications. B. Please inform us of the hydraulic design requirements of the proposed Parkway Boulevard Structure over Cottonwood Creek. This should include discharges to be analyzed, freeboard requirements, velocity requirements, or other hydraulic design criteria, if any. c. Since the criteria for evaluation of flood plain modifications stated in the October, 1987 ordinance will not be applied to this project by the City, please inform us of any ordinance or other published criteria that will be applicable. If the project will be evaluated solely on the basis of FEMA criteria, please advise. D. Please inform us of the city requirements regarding minimum finished floor elevations of proposed structures in areas adjacent to flood plain areas, if any. E. Please advise us of the name of the staff member of either the city or your office to whom we should direct our submittals and will coordinate with us in reviewing our project. . Mr. Wayne Ginn, P.E. JP No. 88009 June 8, 1988 Page 3 of 3 Thank you for your cooperation and assistance in this matter. We would appreciate your written response to the requests stated herein, so that we may have this documentation in our files, by June 17, 1988. If you have any questions or if you are not in agreement with the understandings stated herein, or wish to discuss these topics further, please call. Sincer~ //..~Jer~ Parche' JP:ch cc: Mr. Jay Chester/ABQ Development Jerry Parch Consulting Engineers June 17, 1988 Ms. Maryetta Cunningham Federal Emergency Management Agency 800 N. Loop 288 Denton, Texas 76201-3698 817/898-9284 RE: JP No. 88009; Flood Plain Analysis, Parks of Coppe11; Denton Creek and Cottonwood Branch; Coppe11, Texas Dear Ms. Cunningham: Our firm is serving as engineering consultants to ABQ Development Corporation of Albuquerque, New Mexico on property they have recently purchased in Coppell, Texas. Portions of the property lie in the flood plains of Denton Creek and Cottonwood Branch. Pursuant to my telephone conversation with Mr. Chris Ulsh of Dewberry and Davis, Inc. (Phone No. 703/849-0374) on June 16, 1988 and in order to proceed with preparation of development plans for this site in accordance with FEMA requirements, I request that the Federal Emergency Management Agency provide us with the following information. Existing and most current hydraulic models including output data, of the 10, 50, 100 and 500 year flood plains and the 100-year floodway on Denton Creek from the confluence with Cottonwood Branch upstream to Grapevine Lake. The models furnished to us should contain discharges, and water surface elevations that FEMA will utilize to evaluate any proposed flood plain modifications in this reach. It is my understanding that a portion of the analysis of Denton Creek in this reach is in the City of Lewisville Flood Insurance Study. Existing and most current hydraulic models, including output data, of the 10, 50, 100 and 500-year flood plains and the 100-year floodway in Cottonwood Branch from the confluence with Denton Creek upstream to Bethel Road. The models furnished to us should contain discharges and water surface elevations that FEMA will utilize to evaluate any proposed flood plain modifications in this reach. 6001 W. Interstate 20, Suite 209, LB 32 · Arlington, Texas 76016 · Metro 1817) 572-3458 · (817) 561-2108 Maryetta Cunningham No. 88009 June 17, 1988 Page 2 of 2 Work maps showing cross section locations and alignments utilized in the hydraulic models, stream stationing and 100- year flood plain and floodway limits, and 500-year flood plain limits within the reaches of Cottonwood Branch and Denton Creek previously described. Thank you for your prompt attention to this matter. any questions, please call. Sincerely/~ . Parche', P.E. If you have JP:ch cc: Mr. Jay Chester, P.E./ABQ Development Corporation Jerry Parch% Consulting Engineers June 17, 1988 Mr. Carl Anderson, P.E. Kimley Horn & Associates, Inc. 12660 Coit Road, Suite 200 Dallas, Texas 75251 RE: JP No. 88009; Flood Plain Analysis; Parks of Coppe11; Coppe11, Texas Dear Carl: Pursuant to our telephone conversations of yesterday and today, please prepare for our use the following information regarding your hydraulic modelling of Denton Creek and Cottonwood Branch developed for the City of Coppell. Hydraulic model and output data of the existing watershed and stream conditions of Denton Creek and Cottonwood Branch for all frequency floods you have analyzed. The models should cover Denton Creek from the confluence with Cottonwood Branch upstream to Grapevine Lake Dam and Cottonwood Branch from the confluence with Denton Creek upstream to Bethel Road. Copies of maps showing stream cross section locations within the previously described reaches· Also please indicate a reference station on each cross section on Denton Creek between the Cottonwood Branch confluence and Coppell Road and on each cross section on Cottonwood Branch between Denton Tap Road and Coppell Road. Any floodway analysis you prepared described reaches of each stream. in the previously Maps showing limits of the 100-year and 500-year flood plains and the 100-year floodway, if available, within the previously described reaches of each stream. Please do not prepare any new information pursuant to this request. We are interested in obtaining copies of information listed above as it is currently available· I would appreciate paper copies of all input and output hydraulic models and maps as well as copies of the computer models on floppy diskettes. 6001%R/. Interstate 20, Suite 209, LB 32 · Arlington, Texas 76016 · Metro (817) 572~3458 · (817) 561-2108 Mr. Carl Anderson, P.E. JP No. 88009 June 17, 1988 Page 2 of 2 Please provide additional information in excess of that listed above if doing so will require less effort than trying to minimize the information prepared to only that requested. Also please advise me in advance if your fee for services under this request will exceed $300.00. Thank you for your prompt attention to this matter. I will come by your office on Wednesday, June 22, 1988 at 2:00 P.M. to pick up this information and review it with you. Sincerel~ Y P/archiVe ,/P.E. JP:ch cc: Mr. Jay Chester, P.E./ABQ Development Corporation GINN, INC. June 21, 1988 Mr. Jerry Parche', P.E. Jerry Parche' Consulting Engineers 6001 W. Interstate 20, Suite 209, LB 32 Arlington, Texas 76016 Re: CONSULTING ENGINEERS RECEIVI D jeff/p,rchl Cof~ult~l fmln. Denton Tap Road Improvements and the Parks of Coppell Dear Mr. Parche': This letter is in response to your letters of June 7 and 8, 1988 and questions raised in the meeting with ABQ Development on June 13, 1988. We will address the items in the June 7, 1988 letter first. The easements requested from Univest Development, some time ago, were for the purpose of establishing a temporary working area in which to complete the construction of the road improvements within the existing R.O.W.. The only exception to this is the slight encroachment of the property lines at the locations where the recessed storm water inlets occur. The storm water inlets will encroach the property line about a foot and a half, and therefore we feel it is better to secure an easement around . the inlets now than waiting for future R.O.W2 or utility easement dedications. In the matter of the requested water line extensions, we agree that water mains or services must be extended to the west side of the road. However, the size of, location of, and developer participation in these extensions must be determined prior to adding them to the Denton Tap Road construction contract. We have enclosed blue line copies of sheets 13 through 17 of the paving plans for your use in laying out your proposed water mains or service extensions to serve the ABQ property. According to the subdivision ordinance, ABQ will be responsible for the entire COSt of these extensions, but under the prorata provisions of the ordinance some reimbursement may be available if these extensions are mains which will serve adjacent properties. In our discussions with Mike Allen regarding the median openings and left turn lanes, we agreed to show these as "future" with the exception of the proposed opening at Mills Lane. We stated that we had no objection to the locations of the left turn lanes and median openings shown on the attached "Median-Left Turn Sketch" dated 5-88, by Roberts & Dowdey Civil Engineers, as long .as property owners on both sides of the road agreed on the locations. We cannot include the construction of these facilities in the Denton Tap Road Improvements unless the 17103 Pre~ton Road · S,ite 100 · l,R l IR · Dalla.% Tex&,~ 75248 · Phone 214/248-4900 property owners escrow the cost of them with the City in advance of construction. Also discussed was the improvement of Mills Lane by the adjacent property owners. The Mills Lane intersection can be revised to conform to the future layout of Mills Lane to the west if the property owners will coordinate their efforts with us and give us the surveyed location and design layout Of proposed Mills Lane. The same applies to the west side of the Parkway Blvd. intersection. It is our understanding that you are currently preparing the Parkway Blvd. layout on the west side of the intersection as we discussed so that we may include the entire intersection in the project. In response to the requests in your letter of June 8, 1988 concerning the floodplain issues associated with the properties recently acquired by ABQ we understand by our telephone conversation of yesterday that you have already begun addressing the concerns you had regarding the appropriate hydrologic and hydraulic modeling in paragraph A of your letter. In that regard, we will stipulate that you use the modeling which has been accepted by FEMA, but that you must also use your best professional Judgment in considering other data which is more recent and/or more conservative than that currently in use. Regarding the hydraulic design requirements for the bridge structure on Parkway Blvd. at Cottonwood Branch, the discharges analyzed shall be those that are customarily analyzed for projects of this type. The freeboard requirements shall be such that a two (2) foot clearance be maintained between the proposed base flood elevation and the low chord of the bridge structure. The determination of allowable flow velocities will be based on your best professional Judgment considering the flow conditions and soil conditions, and any concerns expressed by FEMA in their review of your proposed floodplain reclamation models. Items C and D of your letter shall be addressed by Ordinance No. 219, a copy of which is attached. For the interim period until the new City Engineer comes on board and assumes the duties of Floodplain Administrator, the acting City Engineer/Floodplain Administrator, H. Wayne Ginn, P.E., shall receive your submittals and coordinate the reviews mentioned in item E of your June 8, 1988 letter. In response to your request of June 13, 1988 we are also enclosing a blue line copy of the Bid Tabulation and the R.O.W. Map for the project.. I trust that the above information satisfactorily addresses your questions. Si C r , . J H. Wa~e Gtfin, P.E. JCK/HWG/dsp CC: Alan D. Ratliff John C. Karlsruher, P.E. File J-379, 241-044