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HomeMy WebLinkAboutSite Certifications - 09/28/2000 (3)September 21, 2000 J•R ENGINEERING A Subsidiary of Westrian Mr. Jay Barber City of Fort Collins — Stormwater P.O. Box 580 Fort Collins, Colorado 80522 Re: Certification of Storm Sewer Facilities for Harmony._ Village-PUD, Lot_5 .& - - ---- - Dear Jay: JR Engineering (JR) surveyed the existing storm drainage facilities for Harmony Village PUD, Lot 5, on September 1, 2000. The facilities were reviewed in the field by David Klockeman of JR on September 21, 2000. In addition, a Partial Certification letter for the overall site was forwarded to you on May 10, 2000. (A copy of this letter is attached for reference.) As a result of these items, we offer the following for your review and comment: In general, the overall site is in varying stages of construction. However, as all of the improvements have not been installed and portions of the storm drainage facilities are tied directly to these future improvements, this condition is not unexpected. Completed Items: 1. The general grading of the site has been completed in general conformance to the approved construction plans. This item includes the curb cuts at the south end of the parking lot. Items Requiring Further Work: As stated in the May 10, 2000 letter, the channel along between Lots 5 and 6, north of Timberwood was not constructed per the detail shown on fthe approved plans. The approved plans showed a grouted rip rap section and the constructed channel has a concrete bottom with grassed lined sides. The grouted rip rap channel was designed for aesthetic purposes and this section was not required due to design parameters. In addition, the improvements to Lot 6 have not been completed (Lot 6 is currently under construction), leaving the south side of the channel unfinished. 2. Detention Pond B, along the west side of Timberline Road north of Timberwood Drive, is not complete as Lot 6 is'still under construction. However, the majority of the area contributing to this detention pond has not been constructed. 2620 Fast Prospea Road, Suite 190, Fort Collins, CO 80525 970-491-9888 • Fax: 970-491-9984 • w Jrengineering.wm Mr. Jay Barber September 21, 2000 Page 2 of 2 This letter certifies that the "Completed Items" listed above are in general conformance with the plans. The remaining items will be completed as the remainder of the site is developed. If you have any questions or comments, or need additional information, please do not hesitate to contact me at my office. Thank you. Sincerely, JR Engineering 1 0 fit%. Davi . Klockem P.E. Senior Project Manager Attachment 0� ORE K O'e- c> `off C Ft:�o May 10, 2000 Mr. Jay Barber J-R ENGINEERING City of Fort Collins — Stormwater A Subsidiary of Westrian P.O. Box 580 Fort Collins, Colorado 80522 Re: Partial Certification of Storm Sewer Facilities for Harmony Village P.U.D Dear Jay: JR Engineering (JR) surveyed the existing storm drainage facilities for Harmony Village on December 22, 1999, March 23, 2000, and May 4, 2000. In addition, the facilities were reviewed in the field by David Klockeman of JR on February 10, 2000, March 28, 2000, May 2, 2000 and May 8, 2000. A site walk through was held on May 9, 2000 with Jay Barber of the City Stormwater Department, John Tufte of JR and David Klockeman of JR. As a result of these items, we offer the following for your review and comment: In general, the overall site is in varying stages of construction. However, as all of the improvements have not been installed and portions of the storm drainage facilities are tied directly to these future improvements, this condition is not unexpected. Completed Items: The box culvert under Timberwood Drive just west of Timberline Road has been constructed in general conformance to the approved plans. 2. The inlets on Timberwood Drive just west of Timberline Road have been constructed in general conformance to the approved plans. 3. The crosspan at the intersection of Timberwood Drive and Delaney Drive has been constructed in general conformance to the approved plans. 4. The inlet on the east side of Delaney Drive just south'of Timberwood Drive was constructed in general conformance with the approved plans. 5. The pipe connecting the aforementioned inlets to the large junction box on the east side of Delaney Drive south of Timberwood Drive has been constructed in general conformance to the approved plans. 6. The inlet within the parking lot on the west side of Delaney Drive just south of Timberwood Drive was constructed in general conformance with the approved plans. 2620 East Prospea Road, Suice 190, Fort Collins, CO 80525 970-491-9888 - raz 970491-9984 - w Jrmginmring.wm Mr. Jay Barber May 8, 2000 Page 2 of 3 7. The pipes connecting the aforementioned inlet to the large junction box on the east side of Delaney Drive south of Timberwood Drive have been constructed in general conformance to the approved plans. 8. The aforementioned large junction box has been constructed in general conformance to the approved plans. 9. The pipes from the aforementioned large junction box to Detention Pond A have been constructed in general conformance to the approved plans. 10. The main portion of Detention Pond A has been constructed in general conformance to the approved plans. The work remaining includes completion of the fine grading and the permanent vegetation. (Volume calculations are attached.) 11. The pipe from the trickle pan stated in the previous paragraph to the Detention Pond A outlet has been constructed in general conformance to the approved plans. 12. The crosspan at the intersection of Delaney Drive and Wilmington Drive has been constructed in general conformance to the approved plans. 13. The trickle channel and swale on the adjacent property west of the theater was constructed in general conformance to the approved plans. 14. The pipe along the north side of the parking lot in the southwest corner of the site has been constructed in general conformance to the approved plans. (However, the flared end section at the west end of this pipe needs to be grouted at the connection, the silt needs to be removed from the pipe and rip -rap needs to be placed.) Items Requiring Further Work: 1. The channel along between Lots 5 and 6, north of Timberwood was not constructed per the detail shown on the approved plans. The approved plans showed a grouted rip rap section and the constructed channel hasa concrete bottom with grassed lined sides. The grouted rip rap channel was designed for aesthetic purposes and this section was not required due to design parameters. In addition, the improvements to Lots 5 and 6 have not been completed (Lot 5 is under construction), leaving the channel unfinished. 2. Detention Pond B, along the west side of Timberline Road north of Timberwood Drive, is not complete. However, the majority of the area contributing to this detention pond has not been constructed. 3. The inlet along the west side of Detention Pond A on Lot 7, just south of Timberwood Drive, is partially constructed. It is our understanding that this inlet will be completed with the construction of the parking area for this lot. The construction of the building on this lot is currently underway. Mr. Jay Barber May 8, 2000 Page 3 of 3 4. The main portion of Detention Pond A has been constructed in general conformance to the approved plans. The major work remaining includes completion of the fine grading and the permanent vegetation. In addition, the trickle channel at the outlet of the quad -pipes needs to be cleaned of silt and re -surveyed to determine if adequate grade exists. 5. The trickle channel south of Detention Pond A, adjacent to Harmony Crossing Subdivision, was constructed with vertical curb. This pan needs to be backfilled to determine if positive drainage will occur from the rear of the lots in Harmony Crossing (a total of 3 lots). 6. The pipe along the north side of the parking lot in the southwest corner of the site has been extended as part of the construction. However, the flared end section at the west end of this pipe needs to be grouted at the connection, the silt needs to be removed from the pipe and rip -rap needs to be placed. 7. As part of the completion of Item 6, additional rip rap needs to be placed along the north side of the swale at the outlet of the RCP for erosion protection from the RCP and the ADS pipe from the warehouse site. 8. The portion of the internal access road along the rear of the theater just north of Wilmington Drive needs to be repaired to correct the large ponding area. This letter certifies that the "Completed Items" listed above are in general conformance with the plans. The remaining items will be completed as the remainder of the site is developed. If you have any questions or comments, or need additional information, please do not hesitate to contact me at my office. Thank you. Sincerely, A Engineering 11._r4 W- David W. Mockeman, I Senior Project Manager Attachments +E. E!/s� 10 40 IE 9 Project No.: 9168.00 By: DJC,JPZ,AR,DWK Project Name: Harmony Village Date: 5/10/00 V= 1 /3 d( A+ B+ sgrt(A'B)) where V = volume between contours, fP d = depth between contours, ft A = surface area of contour Pond Volume from Approved Drainage Report Area A Volume Area B Volume Contour Surface Incremental Cumulative Contour Surface Incremental Cumulative Total Total Elevation Area Volume Volume Elevation Area Volume Volume Volume Volume ft. . ft. Cu. ft. Cu. ft. ft.) (sq. ft. Cu. ft. Cu. ft. Cu. ft. ac- 50.74 0 0 0 51.00 1044 90 90 51.71 13640 4,368 4,459 90 0.00 52.00 18785 4,682 8141 4,459 0.10 52.52 28143 12120 21260 52.52 0 9,141 21,260 0.21 0.49 53.18 37712 15 536 36 796 53.00 1989 318 318 37114 0.85 53.18 37712 6,704 43,501 53.18 3195 462 781 44,281 44,281 1.02 53.52 39469 13,120 56620 53.52 5472 1456 2,237 1.35 54.00 41949 19,537 76W 0 8687 3,369 5605 81,763 1.88 54A5 45434 19,656 955 14387 5,138 10,743 106,556 245 55.00 49693 26,151 1210 21354 9,766 20509 142,474 3.27 55.45 53348 23179 1455 46192 14,843 35,352 180,496 4.14 5550 53754 2,678 147 48952 2,378 37 730 185,552 4.26 55.62 56201 6,597 154 59043 6.470 44201 198,619 4.56 56.00 63949 22,813 177 90997 28,290 72,490 249,721 5.73 Total re 100 WSEL 3.39 Total ® 100 r WSEL 0.87 4.26 POND A as-hullt Contour Elevation ft. Surface Area s . ft. Incremental Volume (cu. ft. Cumulative Volume cu. ft. 50.89 0 0 0 51.00 4 0 0 51.71 9664 2,335 2,335 3,358 5 6946517 10445 161397963 W52.003610 15 073 31 212 938 20 252 51 464 762 19,606 71070 082 19.089 90159 44695 24 137 114 297 54322 24 715 139012 t 63949 29,535 168,547 Total @ 100 WSEL 3.19 The area for the 56.0 contour is an assumption because the contour actually goes into the parking lot and that area is currently under construction. POND B as -built Surface Area . ft. Incremental Volume Cu. ft. Cumulative Volume Cu. ft. F 0 1136 257 257 6702 3,532 3,790 13056 9,704 13,493 Total W 100-yr WSELI 0.09 Pond B is not complete at this time. 10 YR 00 YR PAGE 1 OF 1