Loading...
HomeMy WebLinkAboutWOODLANDS PUD - Filed GC-GENERAL CORRESPONDENCE - 2008-08-05i e VA- Quo *90 CORNER CONSUITINCf COMPANY P.o. box 6* FORT COHM, ColoRAdo 80522 pl 0n : (303) 482_6650 W MANAGEMENT/ENGINEERMG February 16, 1979 1 N Mr. Mauri Rupel Development Engineer City Engineering Department City of Fort Collins P.O. Box 580 Fort Collins, Colorado 80522 Re: The Woodlands. Dear Mauri: ,-�&je, As we proceed with utility plans and final plat preparation for The Woodlands project, we will be breaking the total project into two phases. Phase I will consist of the northwest portions (40+a of the total project). — We will design access from Harmony Road at this time. However, we would prefer to postpone design of the Harmony Road flowline and the adjacent drainage channel west to Shields Street, and include them with plans for the balance of the project. If you have any objections with this approach, please give me a call. Very truly yours, CORNELL CONSULTING COMPANY Harry AUCornell, P.E. President 3AC:fsr c: Sam Heiter Wood Bros. Homes, Inc. Eldon Ward ZVFK Architects CORNED CONSU[TINC{ COMPANY po box 646 bRT col[ Ns, c010Rndo 80522 pla\E: (303) 482,6650 MANAf,EMENT/ENGINEERING April 1, 1980 Mr. Bob Smith Engineering Department City of Fort Collins P.O. Box 580 Woe DLAuh S Fort Collins, Colorado 80522 Dear Bob: This letter is to confirm the decisions concerning Mail Creek at Shields Street made during our meeting on April 1, 1980. Marc Engemoen expressed the opinion that the underground improvements should be sized for a 2-year historic upstream flow. He further stated that final street construction in the proposed channel north of Harmony Road be postponed and that a temporary road section acting as a high flow spillway be installed. We concur with this approach. Our construction plans will show the appropriately sized culverts at Shields Street, Starflower Drive, and at Harmony Road approximately 1/2-mile east of Shields, together with improvements to the existing Mail Creek Channel. As stated, the culverts will be sized to accommodate 2-year historic flows, and the channel and Starflower Drive will accommodate 100-year historic flows. We will also set all building elevations well above the 100-year flow for existing upstream conditions. Due to site planning constraints we find it necessary to use on -channel detention ponds to provide the required detention volume at the site. You indicated approval of this approach provided a trickle channel for minor flow is incorporated. I'f there are any discrepancies between this letter and your understanding of the meeting or any omissions of note in this letter, please contact us so we can base our final design on that understanding. In any case, we should be submitting the final design for your review in 2 weeks. Sincerely, CORNELL CONSULTING COMPANY Bill Blackwell Senior Designer BB/fsr cc: Wood Bros. Homes, Inc. Attention: Mr. Wayne Matsuda ENGINEERING SERVICES DATE: MAY 13, 1980 TO : DAVE STRINGER, CHIEF CONSTRUCPION INSPECTOR THRU: ROY BINGMAN, DIRECTOR OF ENGINEERING SERVICES FROM: MAURICE RUPEL, ASSISTANT CITY ENGINEER - DEVELOPMENT '%X0-�' RE : ENGINEERING RELEASE FOR C.O.'S Reference is made to your letter of April 25, 1980, (copy attached) con- cerning Woodlands, P.U.D. It is my opinion that you and your crew acted prudently and in the best interest of the public when you issured the C.D.'s in question. The City Code specifically states we must issue C.D.'s when some financial security is offered by the developer to complete the paving. We have a copy of National Fire Insurance Company of Hartford's Bond #554-40-01 in our files covering the quarantee. With reference to your second and third questions, the failure of the base and/or sub -base during extreme and unusual weather can only be termed "An Act of God", and to deny the owner a C.O. would in my opinion, be unwarrented. There is no way we can (and should) be expected to insure the public against all these circumstances. HoaAlever, I do think the seller has a moral obliga- tion to inform the buyer of these possibilities, but, we as the publics quardian, should not assume our quardianship includes protection against all possibilities. — MR:laa I \.r *04 April 25, 1980 TO: Mauri Rupel, Assistant City Engineer - Developmment MM'34: Dave Stringer, Chief Construction InsuectoLS9 RE: Engineering release for Certificates of Occupancy In the A.M. of April 23rd, Rood Brothers, Inc, requested engineering releases for certificates of occupancy on two houses in their woodlands Subdivision. The construction inspector made an on -site visual inspection of the based street, sidewalk,curb aryl gutter and any other public right-of-way improvements. All construction was ccmpleted as specified by City Code and the Utility Agr_eerent with the exception of street paver .cent. In the field inspector's judgment the tc,A addresses on 4bIlyhock Street were okay for engineering releases, and the release forms were then sent to Building Inspection. On April 24th the Building Inspector for this area notified our department that Hollyhock Street was not adequate for automobile traffic or emergency equipment, due to the amount of moisture fran rains on the 23rd and 24th, and inquired has an engineering release was obtained. My questions are as follow: * How do we handle this situation if it should (and it probably will) arise again? * Can we force the issue that all streets are to be paved prior to engineering releases for certificates of occupancy? * Release certificates of occupancy on unpaved streets then if the streets became irmossible, red tag the buildings or subdivision after having already released the houses? * Is this fair to homeowners who are looking fonrasd or need to close on these hor s? I would appreciate your camsments and suggestions to this problem. e--z_ cc: Roy Bingmnan J r CORNEA CONSUITINq COMPANY Ro box 646 FORT UAIINS, coloRAdo 80522 p KMF (303) 482.6650M MANAf EMENT/ENGINEERINgj November 25, 1980 Mr. Tom Gaffman Inspector City of Fort Collins Dear Tom: The purpose of this letter is to provide you with a scope of design change for the storm culvert crossing at Shields Street just north of Harmony Road. We have gone to quite a bit of effort to "thread" a 36" storm sewer through the existing utilities under Shields Street. The last utility to be relo- cated was the Mountain Bell Toll Telephone Cable. Our design (attached) called for the cable to be raised 3.5' and moved west 6 feet. In reviewing the stakes set in the field, we find that they have apparently just raised the cable and have not moved it west. Rather than call them out again, we propose to install a 4 foot manhole at that location rather than a 5 foot manhole. We would pour an extra large base and sides to provide some extra support for the manhole above the 36" pipe to compensate for not having a 5 foot manhole. We have spoken to Mr. Bob Smith, City Drainage Engineer, regarding this prob- lem, and he is in concurrence with our proposal. We expect construction to begin tomorrow, November 26, 1980. If you have any questions, please call me. Sincerely, CORNELL ONSULTING COMPANY �4L Wr Gregor A. rst Projec Ma qer GAH:nmd Attachment CC: Bob Smith Jack Sullivan, Loveland Excavating i ti a w e wa VV n_ ti W CJ I N O U .Z-� d V F U a Q O Z rZ O . ` O-� n-i C) O F- 3 Z W W Fw- E , OL Z z w U V �0= W OUf VV NC'NN Y. Zf.7 U V Z Q Z rZ. W x U x • Q �U. d-<d x ¢' '7 V$ I dF- I =WQU W F- �O N . 1p d .•+ W 2' m .N p Fw-HxOw W ill wow a3x wF-WD aCC H- Hwu�. P • O • UGH U W Z I I Z -+ Y N WI Oxr+ N3 OO>OO�ow I - JNOU. th f �p F- ^ R2p! Z N m u/ (O/ .fo O/ /Amor ND 'Awl0vb (a�oyd ur uiA4.U4a• W .07 v�ayy avnsr 4 . N,.Q I I I ICI �I i t LO i� w a o T 0 u 0 Sw W®D BROS. HONES December 26, 1979 Mr. Mauri Rupel, Development Engineer Public Works Department Post Office Box 580 Fort Collins, Colorado 80522 Dear Mr. Rupel: W /5le WOOU4P"h� Pa 13 RE: Sanitary Sewer U derdrain Blockage - oodla Larkborough Subdivision y Because Wood Bros. Homes has recently received adverse comments (of an unofficial nature) from the City of Ft. Collins relating to the referenced problem, I thought it appropriate to write this letter explaining the situation, its origin, and possible solutions. The ground water table in the referenced subdivisions is such that sanitary sewer under - drains are highly advisable where basements are contemplated. However, the flat terrain and other physical features make it somewhat difficult to obtain a positive gravity outfall underdrain system other than by means of a continuous system, continuing from subdivision to subdivision, paralleling the sanitary sewer lines with respect to both location and grade. In Larkborough Subdivision immediately east of our Woodlands development, being developed for use by American Builders by Art Builders, Inc. (Mr. Art Hausman, President), a splendid opportunity existed for the creation of a positive gravity outfall system, utilizing the trunk sewer line constructed by the City of Fort Collins under College Avenue and westerly under the railroad tracks lying east of Larkborough. The Parks Department in FortCollins, as I understand it, wished to use the underground water collected in Larkborough for the purpose of irrigating a park located somewhere east of College Avenue. Art Builders, Inc. had reason to believe that the sanitary sewer line would have sufficent gravel bedding to act as an underdrain. Apparently through poor communication between the Parks Department and the Utilities Department, the sewer trunk line was ultimately built so that blockages in the gravel underdrain system were created at the points where the sewer was bored under College Avenue and under the railroad. Therefore, the trunk line could not, after all, serve as a sub -surface water collector. Despite the fact that Art Builders has sufficient cause to rely upon the existence of this underdrain, the City ultimately refused to go back and create the condition originally promised, which would have been expensive. Thus, it appears to me that the City set the trap which inadvertently caught both Art Hausman and Wood Bros. Homes. About the middle of May, 1979, it came to Wood Bros. attention that there was indeed a sanitary sewer underdrain system being constructed in Larkborough, a system which could also serve The Woodlands. Wood Bros. was in the final stages of design on Woodlands Filing no. 1, and without utilizing Larkborough's system, we had discovered that full 2103 South Wadsworth Blvd., Denver, Colorado 80227 303i985-8751 Mr. Rupel Page 2 underdraining of our property would probably not be possible, a condition therefore requiring sump pumps in some basements not the most desirable condition. It was obvious from the soils information acquired by both Empire Laboratories in behalf of Wood Bros., and F. M. Fox & Associates, Inc. in behalf of Mr. Hausman, that under- ground water historically progressed from the Woodlands area into the Larksborough area; therefore, in the long run, it appeared that the Larkborough system would ultimate- ly transport water originating in the Woodlands property in any event, whether or not the areas were actually connected by pipe. On or about May 20, 1979, I contacted Mr. Hausman and asked him if he had any objection to our tying into the system in Larkborough. His statement at that time was that "Don Clark of F. M. Fox & Associates designed our system and has done our soils work. If he has no objection to the tie-in, it's fine with me." On May 21, I contacted Don Clark by phone. He stated that he would look into the matter, reviewing our soils data, and would give us permission to tie in to the system if he saw no problem with it. Clark subsequently did a fairly thorough investigation (at our expense) and wrote a letter to Wood Bros. on July 27, 1979 (copy enclosed) which stated in part, and in effect, that the Larkborough system and its outfall as proposed at that time would be capable of handling our underdrain. Mr. Lloyd McLaughlin of M&I Consulting Engineers (Art Builder's design engineers), as well as Don Clark, were fully aware from that point forward that Wood Bros. was planning to tie into the Larkborough system. Although Wood Bros. did not, and does not, have written permission from Mr. Hausman relating to this tie-in, I was sincerely under the impression that I had met the conditions stipulated by him; in any event, Art Builders, Inc. was fully aware that we were making, and did make, the necessary connection, and voiced no objection. Subsequently, Art Builders and it's engineering representatives discovered that the City sewer trunk line would not serve the purpose originally anticipated; therefore, the Larkborough underdrain ultimately would be forced to drain by means of an existing 12" perforated subdrain located under the lined section of the New Mercer Canal. In order to obtain a gravity connection to this Canal underdrain, it would have been necessary to deviate the underdrain pipe from the sewer grade throughout the lower 1/4 mile, more or less, of the Larkborough development. Art Builders elected not to do this, and instead simply flattened the grade of their underdrain pipe over the last three or Four hundred feet before tying into the Canal underdrain. Unfortunately, this creates a dangerous condition from several points -of -view. Water (from the underdrain) now must saturate the street subgrade and sanitary sewer line in Larkborough to the extent that it builds a "head" of two to three feet some distance upstream from the Canal underdrain so that the collected water can travel throuoh the gravel bedding and eventually into the underdrain. This is a very low -volume condition as far as handling underground water is concerned, and problems immediately began to develop. Art Builders next step (a step, incidentally, which was not recommended by its own soils engineer, Clark) was to dig down in the street at the boundary between Woodlands and Larkborough and physically block the connected underdrain systems by disconnecting the pipes involved and placing a large clay barrier in the street in the vicinity of the sanitary sewer line. .rO Mr. Rupel December 26, 1979 Page 3 It is my opinion that this should have created alarm within the City staff, because this blockage was known to City inspectors at the time it was made; it is contrary to the approved plans of both Larkborough and the Woodlands, because the underdrain involved is shown on both sets of plans in such a fashion that the intended connection was quite clear. Now we have a situation in which sub -surface water• is apparently backing up in the easterly portion of Lark Bunting Drive in the Woodlands and infiltrating into the sanitary sewer line in some substantial amount, a condition which is not surprising. Incredibly, it has come to our attention that the City of Fort Collins appears to be pointing the finger at Wood Bros. It is my sincere opinion that of the three parties involved (The City of Fort Collins, Art Builders, Inc., and Wood Bros. Homes) the one least responsible for the creation of the problem, and totally powerless to solve the problem, at least on a short-term basis, is Wood Bros. Furthermore, the blockage of the piped underdrain at the west edge of Larkborough probably will give only temporary relief to the serious problem Art Builders has at its eastern boundary. Regardless of any actions which can be taken by Art Builders, Inc., the Woodlands ground water will eventually proceed in an easterly direction, and Mr. Hausman's problem will reappear. This I believe, is generally the opinion of Mr. Hausman's soils engineer, Don Clark. I think it may be possible for Wood Bros. to intercept its own underdrain line at its (The Woodlands) eastern boundary; extend it in a due -south direction for some distance; build a lift station, and pump the collected ground water prepetually into a detention pond already in existence in that area. Whether or not this ultimately proves to be feasible and possible, we hereby take the position of insisting that the blockage created by;Aft Builders, Inc. at our eastern boundary be removed; its existence will ultimately create problems in the Woodlands (especially within the City street right- of-wa,p) even if we are able to relocate the ultimate terminal point of our underdrain. In summary, I am of the opinion that the City of Fort Collins has a very substantial responsibility in this matter, based upon its earlier misdirection to Art builders, Inc.; I also believe that problems will become apparent eventually in the easterly portion of Larkborough with or without the piped ground water contribution from the Woodlands. Up to this point, Wood Bros. has clearly indicated that it is willing to participate in a solution to the problem at the east end of Larkborough, in exchange for continuing our underdrain connection; obviously, if we are forced to go a different route a considerable expense to ourselves, we will divorce ourselves from the problem farther east and Art Builders and the City of Fort Collins will ultimately have to solve it without our financial assistance. Admittedly, there is a variation in viewpoint as held by myself %Wr 15 Mr. Rupel December 26, 1979 Page 4 and Mr. Hausman at this time. I really don't believe these are serious, I hope they aren't, but they are, in any event, immaterial. Art Builders and I think a day of reckoning will eventually occur. Possibly the best this point in time is a financial cooperation between all three parties, not excluding the City. Sincerely, WOOD BROS. HOMES, INC. Sam Heiter, vice President Land Development Manager Colorado Region HSH:aa CC: Art Hausman, Art Builders, Inc. Ed Englebrecht, Wood Bros. Wayne Matsuda, Wood Bros. Enclosure and at least has a problem solution at definitely ` F g Consulting Engineers and Geologists ®_ July 27, 1979 Mr, Peter Spiska Wood Brothers Homes, Inc. 2103 South Wadsworth Boulevard Denver, Colorado 80227 F.M. FOX & ASSOCIATES, INC. 4765 INDEPENDENCE STREET WHEAT RIDGE, COLORADO 800M (303) 424-5578 - FMFOX Job No. 1-1107-4293 Subject: Underdrain Design Feasibility Study for the Connection of the Proposed Woodlands Subdivision, Larimer County, Colorado with Larkborough Subdivision, Larimer County, Colorado. Reference: Underdrain Specifications for the Proposed Larkborough Subdivi- sion, Larimer County, Colorado, our Job No. 1-1107-3964. Empire Laboratories Report Soils and Foundation and Geologic Investigation for Cornell Consulting Company, Fort Collins, Colorado, Project No. 3448-79. At your request, a hydrological study was conducted to determine the feasi- bility of connecting the proposed Woodlands Subdivision underdrain system with the existing Larkborough Subdivision underdrain system. Both subdi- visions are located in Larimer County, Colorado, with the Woodlands site adjacent to, and west of, the Larkborough site. This report presents data from our calculations as well as our conclusions and recommendations for the proposed connection. Anticipated ground -water flow from the Woodlands Subdivision was calculated from data atories, Inc. reort. Theconclusions 7and trecommendations eare cbased ed ponethese rcalculations, asp pwell as our own design data for the existing Larkborough underdrain system and our experience with similar ground -water conditions. An anticipated ground -water flow from the proposed Woodlands Subdivision was co,��puted to be approximately 0.10 cubic feet per second at the connection point. This value was calculated using an assumed permeability of 1 x 10-4 feet per second. This value was then used to compute an additive ground -water flow value for that section of the Larkborough Subdivision located at the proposed connection point. Time of concentration calculations were then computed to construct an additive peak discharge curve to determine the maximum probable flow rate that would exist at any one time in the Larkborough underdrain system. This peak flow rate value of 0.46 cfs was then compared to the maximum flow capacity of the existing Larkborough underdrain system. ALBUOUEAOUE • DENVER • PHOENIX 0 Mr. Peter Spiska Wood Brothers Homes, Inc. Job No. 1-1107-4293 July 27, 1979 Page Two The calculated peak flows from the time of concentration calculations indicate that the additional flow expected irl, +a arkbo.bugh.SubdivlsionµQ ?,to the ? Woodlands Subdivision connect �dn wtl'I 11at`pxtet� 'the` capacity of t e designed • Larkborough underdrain system Additional information has been supplied to this firm by M & I Consulting Engineers concerning the relocation of the outfall for the underdrain of Larkborough Subdivision. It is our understanding that the system could not be led to a positive gravity discharge because no provisions had been made by the City of Fort Collins to extend the system through the railroad embankment located to the east of Larkborough as originally designed. It is our under- standing that the system has been alternatively discharged into an existing 12 inch diameter perforated underdrain constructed to the south of the site, which outfalls into Mail Creek at a slope of 0.16%. Portions of the under - drain system will be relayed in order to accommodate this new outfall. The existing underdrain has been used in the past for drainage of agricultural ground. The expected flow in this underdrain is not available; however, calculated flow rates for the existing system show that it is more than adequate to handle the design flows of both the Woodlands and Larkborough underdrains. It is also reasonable to assume that the existing system (at its indicated location) has been dewatering portions of Larkborough Subdivision which will now be intercepted by the Larkborough underdrain system, thus reducing its total design flow. We recommend consultation with Art Builders, Inc. to to the system, especially to insure that a positive tained. We are available to discuss the details of Please call when further consultation is required. F. M. FOX & ASSOCIATES, INC. 40fiald L. Taylor, Jrf Staff Engineer DLT/cae �p15TFR f..9,A *'014395W� 1,4 •' O Copies: 3 - Wood Brothers Homes, Inc. 1 - Art Builders, Inc. 1 - American Builders verify the outfall point gravity outfall is main - our evaluation with you. Revi wed by Donald R. Clark Division Manager r CITY OF FORT COLLINS ENGINEERING DIVISION t r P.O. BOX January 4, 191'5/w--Q Mr. Sam Heiter, Vice President Wood Brothers Homes 2103 S. Wadsworth Boulevard Denver, Colorado 80227 Dear Sam: FORT COL Re: ✓The Woodlands, P.U.D. and The Tarkborough Subdivision PH (303) 484-4220 We would like to take this opportunity to commend Wood Brothers Homs and you, particularly, for the manner in which you responded to our request for a joint meeting between yourself, Art Builders, F.M. Fox & Associates, Soils Engineers, M&I Consulting Engineers, and the City. We all expected that the difficulties outlined in your letter of December 26, 1979 concerning suhdrains within the referenced subdivisions could be resolved upon a joint meeting between all parties concerned. Our meeting of yesterday, January 3, 1980 justified our expectations. To reiterate, you have agreed to seek an outlet for your subdrains separate from the subdrain system established within the Tarkborough subdivision. If this outlet cannot be accomplished by gravity flow directly to "tail Creek (the natural drainageway for the area), you will provide a wet -well and lift station system which will lift the subdrain effluent to your detention pond which does, in turn, discharge into Mail Creek. Since the Woodlands is a P.U.D., the maintenance and operating expense of the lift station shall be the responsibility of the Woodlands Home owners Association in perpetuity. Art Builders will remove the clay dam between their subdrain system and the Woodlands P.U.D. when your subdrain system has a permanent outlet as described above and will replace the clay with suitable backfill so as to provide a suitable subbase for the street wherein the clay dam now exists. Prior to your permanent solution, you have agreed to provide a temporary purge to discharge your subdrain at the surface to allow the subdrainage system an outlet to Mail Creek and provide relief for the present subsoil saturation. EXT. 728 0 Mr. Sam Heiter Page Two If our understanding of the alove agreed -to Procedures is not in accord with your understanding, Ialease advise us ijaiccdiately. By copy of this letter I wish to express my gratitude i.o Art Ilatzsrnja for his contribution to the meeting and ask his conf.irnkat.on of the Procedures outlined. Thank you for your continued cooperation. Sincerely, ✓14aurice E. Rupel, P.E. & L.S. Develoriwnt Engineer cc: Art Hausman, Art Builders, Inc. Ion Clark, F.M. Fox & Assoc. Lloyd McLaughlin, M&I Roy Bingman Dave Stringer c f