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HomeMy WebLinkAboutOLD TOWN NORTH - FDP - 28-99C - SUBMITTAL DOCUMENTS - ROUND 1 - STORMWATER-RELATED DOCUMENTSPage 6 January 7, 2002 Project No: 1646-01-98 Re: Old Town North Floodplain Review Response to Floodplain Comments, dated July 6, 2001 R Regarding the third bullet, since garages will be built at or above the minimum protection elevation, no discussion of hydraulic venting is provided. 25. "Since you are elevating the ground so much, it might be worth considering going through the FEMA LOMR-Fill process to remove the site from the Floodplain. This will save a great deal of money in flood insurance premiums for the future homeowners. " R Acknowledged. We trust that this response has addressed all of your specific comments and concerns. If you have any questions or further comments during your next detailed project review, please call at (970) 226-5334. $inceAly, � I 1 Michael Rohlfs t Shear Engineering Corporation cc: Monica Sweere; Palladian Construction Co. Troy Jones; City of Ft Collins, Planning Russell Lee; BHA Page 5 January 7, 2002 Project No: 1646-01-98 Re: Old Town North Floodplain Review Response to Floodplain Comments, dated July 6, 2001 R Two figures have been added presenting the various defined elevations for slab on grade and crawl space situations. 20. "Please change the column name '500-year flood protection (@+1.5ft) ' to 'Regulatory flood protection elevation (500 year WSEL + 1.5 ft.) " R Acknowledged. The column heading has been changed as requested. 21. "Please add a column that lists the lowest floor elevation. Remember lowest floor inchudes the bottom of the basement or crawl space. " R A column has been added as requested. A note accompanies the table further clarifying the elevation represented. We are in process of calculating the remaining lot corner elevations. Once these are completed, this sheet will be provided for review once completed. 22. "Please change the calculations in the column that is labeled 'level of protection' to be (lowest floor elevation — 500 year flood elevation). All values should be 1.5 ft. or higher. " R Acknowledged. Once grading is completed by tabulating the lowest floor elevations, this column will present the "level of protection" as request. 23. "In spot checking the 500 year elevations in the table, many were found to be incorrect. See items marked with an '-'. Please review and revise as necessary. A complete review by the City of all BFE's will need to be completed during the next round of review. " R Acknowledged. Both the 100-year and the 500-year WSEL's have been recalculated following the redlined corrected station designations and their respective WSEL's. } 24. `Please add the followif:g notes about floodplain issues: • Include notes from drainage report about floodplain use permit being required before building permit being issued and that a FEMA elevation certificate is required prior to issuance of the CO. • Define 'lowest floor elevation' as including bottom of basement or crawl space. • Discuss hydraulic venting of garage if needed. " R Two notes have been added to the plans as requested in the first bulleted comment. R A note has been added to the Drainage and Erosion Control Notes Plan defining the lowest floor elevation as including the bottom of a basement or crawl space. Two figures have been added to the sheet providing a visual representation of the elevation configurations. Page 4 January 7, 2002 Project No: 1646-01-98 Re: Old Town North Floodplain Review Response to Floodplain Comments, dated July 6, 2001 R As discussed above, these items are now shown on the "Floodplain Plan." The cross -sections have been relabeled following the redlines. 16. "On the drainage plan, please make all labeling of cross -sections and BFE labeling readable. " R These items are more clearly shown on the new sheet "Floodplain Plan." 17. "On the drainage plan, please add the BFE symbol to the legend. " R A symbol for BFE has been added to the legend on the new sheet titled "Floodplain Plan." Drainage Notes (Sheet 60) 18. "Add a cohrmn for 100 year WSEL. This will be needed for completing the elevation certificates for the CO. By having this already prepared, it will make it easier for completing the elevation certificates. " R Acknowledged. Column added and completed with respective 100-year WSEL's. 19. `In your response to previous comments, you said the Actual Finished Grade' will probably be the garage slab. Please change column label to reflect this (i.e. label should say 'garage slab elevation ). " R This table has been extensively modified. Columns have been added and headings have been changed, all in an effort for clarity. Highest Lot Corner is the first new column. This column is used as a reference elevation from which other elevations are calculated. The next column is the Actual Finished Grade (Highest Lot Corner + 1.5'), and presents the calculated finished grade elevation for each lot. Minimum Top of Foundation Elevation (Highest Lot Corner Elevation + 2.0') is the next column. The next column Actual Lowest Floor Elevation is the design elevation for each building. A check within the spreadsheet is performed comparing the Minimum Top of Foundation Elevation with the Regulatory Flood Protection Elevation. The elevation presents the highest elevation from the two columns. The final column, Actual Lowest Floor — 500 yr WSEL presents the difference between the top of foundation and the 500-yr WSEL. Any value greater than or equal to 1.5 is required. R Notes have been added providing further clarification to the elevations. Page 3 January 7, 2002 Project No: 1646-01-98 Re: Old Town North Floodplain Review Response to Floodplain Comments, dated July 6, 2001 11. "P.20 In the Compliance with Standards section, please list the Floodplain regulations in Chapter 10 of City Code. " R Text has been added. Reference is made to the document titled "Code of the City of Fort Collins", Chapter 10 - Flood Prevention and Protection. Reference section VII.A.3. Miscellaneous Plan Sheet Comments 12. "Please show the Dry Creek floodplain and floodway boundaries, as well as the Poudre River floodplain boundaries and Product 6 Corridor on the Plat. See previous comment. " R Acknowledged. This item being coordinated with the surveyor. 13. "See previous comment about having floodplain, floodway and Product 6 boundaries on the grading plan. " R These items have been added to the grading plan as requested. Drainage Plan (Sheet 59) 14. "Suggest making a separate map for the Floodplain, instead of trying to have everything shown on the one drainage plan. The items to include on this separate map would be: • Floodplain and floodway lines for Dry Creek • Floodplain lines for the Poudre River • Product 6 corridor for the Poudre River • Cross-section and BFE lines for Dry Creek and the Poudre River • Lot lines, lot numbers, streets, block numbers, phase lines • Table with flood elevations" R Acknowledged. A sheet has been added to the plans titled " Floodplain Plan." This sheet includes items requested above. The Drainage Plan has been "cleaned up," by removing items shown on the new sheet. 15. "On the drainage plan, some of the cross -sections are mislabeled. Please review and modify. " Page 2 January 7, 2002 Project No: 1646-01-98 Re: Old Town North Floodplain Review Response to Floodplain Comments, dated July 6, 2001 R Text has been added. Reference section Ill. A.1.c. 6. "P.6 Please include the table shown on Sheet 59 of the plan set that lists the 100 year and 500 year WSEL's at the cross -sections in the project area. " R Two tables have been added. Reference section III.A.2, and III.A.3. 7. "P.7 In the regulation section, please mention the floodplain regulations found in Chapter 10 of the City Code. " R Text has been added. Reference is made to the document titled "Code of the City of Fort Collins", Chapter 10 - Flood Prevention and Protection. Reference section IV.A.4. and VIII. 8. "P.8 Please make a note that all structures will have to have their lowest floor elevated 18" above the 500 year flood elevation. Please discuss venting of garages, if applicable. " R Text has been added. Reference section IV.A.3. R Garages will be constructed above regulatory flood protection elevations and will not require hydraulic venting. 9. "P.8 Please clarify in the report why the 500 year elevations instead of the 100 year elevations are being used. Suggest language is written in the report. " R A brief statement addresses the design protection elevations for the project. Reference section IV.A.3. as written: "All lots within Old Town North which are located within the Dry Creek floodplain, but not within the Poudre River floodplain, will be protected from the Dry Creek 500- year WSEL as currently defined by the Lower Dry Creek Basin Master Drainage Plan. The lowest floor elevation shall be 1.5 feet (18 inches) above the 500-year W SEL." 10. "P.16 Please include a statement about needing to obtain a floodplain use permit for each structure prior to obtaining a building permit and that a FEMA Elevation certificate is required for each structure in order to obtain a CO. Please make this note on the plans, as well. " R Text added. Reference section V.F. Le, and V.F.l.f. R As requested, notes have been added to the plans regarding the above. January 7, 2002 Project No: 1646-01-98 City of Fort Collins P.O. Box 580 700 Wood Street Ft. Collins, Colorado 80524-0580 Attn: Marsha Hilmes-Robinson Re: Old Town North; Ft. Collins, Colorado (Project Development Plan) Response to Floodplain Review Comments, dated July 6, 2001 Dear Ms. Hilmes-Robinson: This is a response to your project comments regarding Old Town North Floodplain Review. Original comments and responses to each are provided. Drainage Report 1. "P. 6 Please change the term ' inished floor' to the 'lowest floor'. " R As requested, the text has been changed. 2. "P.6 Please make a note that says that the lowest floor elevation includes the bottom of the basement or crawl space. " R Text has been added. Reference section III.A.3.a. 3. "P.6 Please discuss the type of foundation construction for the homes (i.e. slab -on -grade, crawl space, basement, etc.) " R Text has been added. Reference section III.A.3.c. 4. "P.6 If any of the garages are not going to be elevated above the regulatoryflood protection elevation, please discuss the hydraulic venting requirements. Please note that all mechanical equipment servicing the building would still need to be elevated to the regulatory flood protection elevation. " R Acknowledged. Garages are to be constructed slab -on -grade at elevations greater than the regulatory flood protection elevation. Therefore, no hydraulic venting will be necessary, nor discussed in the drainage report. S. "P.6 Please discuss the location of the Dry Creek floodway. Please state that no construction will be done within the floodway in this phase. " 4836 S. College, Suite 12 Ft. Collins, CO 80525 (970) 226-5334 Fax (970) 282-0311 www.shearengineering.com