The URL can be used to link to this page

Home My WebLink AboutMemo - Mail Packet - 7/21/2020 - Memorandum From Ken Sampley And Heidi Hansen Re: Notification Of Revised 100-Year Floodplain For The Old Town Basin1 of 1 Utilities electric • stormwater • wastewater • water 700 Wood St. PO Box 580 Fort Collins, CO 80522 970.221.6700 970.221.6619 fax • 970.224.6003 TDD utilities@fcgov.com • fcgov.com/utilities DATE: TO: THROUGH: FROM: RE: July 02, 2020 Mayor Troxell and Councilmembers Darin Atteberry, City Manager Theresa Connor, Interim Executive Director, Utilities Matt Fater, Interim Deputy Director Water Engineering Ken Sampley, Director, Civil Engineering Heidi Hansen, Civil Engineer III, Water Utility Engineering Division Notification of revised 100-year floodplain for the Old Town Basin. Informational Item: This is provided for informational purposes; no action is required by Council. Background and Project Purpose A new floodplain and floodway based on the design and construction of the Mulberry-Riverside Drainage Improvements Project extending from the intersection of Mulberry and Cowan Streets to Riverside Avenue and Myrtle Street has been adopted by the City of Fort Collins Utilities. The purpose of the project was to provide a new storm sewer and inlets to address localized drainage problems and reduce the effects of flooding during major storms. The project was constructed by the City of Fort Collins. The Mulberry-Riverside Drainage Improvements Project is located in Sections 12 and 13 of Township 7N, Range 69W, near the intersection of Mulberry Street and Riverside Avenue in Fort Collins. This update is only related to the City-regulated Old Town Basin. Due to more detailed mapping and the Mulberry-Riverside Drainage Improvements Project, all structures are now in the Moderate Risk floodplain. Attached is the approval letter and maps of the floodplain revisions showing the pre-project and post-project floodplain. Citizen Notification Fort Collins Utilities will be notifying citizens of the impact this project has on their properties and residences. A personalized letter with map inserts detailing pre and post project floodplains will be sent to each owner and resident. Attachments: 1. Map approval letter including revised maps DocuSign Envelope ID: F858FCD5-309F-49EF-AB74-970088BBD229 1 of 2 Utilities electric • stormwater • wastewater • water 700 Wood St. PO Box 580 Fort Collins, CO 80522 970.221.6700 970.221.6619 – fax • 970.224.6003 TDD utilities@fcgov.com • fcgov.com/utilities DATE: May 22, 2020 TO: Theresa Connor, Interim Executive Director, Utilities THROUGH: Matt Fater, Interim Deputy Director Water Engineering FROM: Ken Sampley, Director, Civil Engineering Heidi Hansen, Civil Engineer III, Water Utility Engineering Division Daniel Evans, Civil Engineer III, Water Utility Engineering Division RE: Updated Floodplain Map Approval for Old Town Basin Background and Project Purpose In 2003, City Council adopted the current Old Town Stormwater Master Plan for the City of Fort Collins and it is referenced in City Code Section 10-19(b). In 2018, Icon Engineering, Inc. updated the floodplain and floodway near Mulberry Street and Riverside Avenue based on the Mulberry-Riverside Drainage Improvements Project extending from the intersection of Mulberry and Cowan Streets to Riverside Avenue and Myrtle Street. The project is located in Sections 12 and 13 of Township 7N, Range 69W, near the intersection of Mulberry Street and Riverside Avenue in Fort Collins. The purpose of the project was to provide a new storm sewer and inlets to address localized drainage problems and reduce the effects of flooding during major storms. The project was constructed by the City of Fort Collins. This update is only related to the City-regulated Old Town Basin. Due to more detailed mapping and the Mulberry-Riverside Drainage Improvements Project, all structures are now in the Moderate Risk floodplain. Attached are maps of the floodplain revisions showing the current regulatory floodplain and post-project floodplain. The floodplain modeling report is on file and shall be maintained by the office of the Utilities Executive Director. DocuSign Envelope ID: 6C2F2FF7-F858FCD5-D862-309F-4735-49EF-92C2-AB74-4A651831D4B3 970088BBD229 2 of 2 Floodplain Map Approval Recommendation In reference to the adoption of updates and refinements to the floodplain or floodway mapping that modify the currently existing floodplain mapping, City Code Section 10-19(b) states: . . . To the extent that additional technical analysis results in the refinement of the floodplain, flood fringe, floodway, erosion buffer zone or other delineations contained in the plans listed below, or to the extent that the completion of a capital improvement project results in a modification of any such delineations, the Utilities Executive Director shall, pursuant to his or her duties as set forth in Paragraph 10-26(9), document the associated change in the delineation, which modified delineation shall control the application of the requirements set forth in this Article. A copy of the studies or reports shall be on file in the permanent records of Utility Services. Documentation of any modification of any delineation pursuant to this Subsection shall be on file in the permanent records of Utility Services. The floodplain/floodway update presented with this memorandum is considered an update to the adopted map based on policies and design criteria adopted by City Council. Therefore, we recommend approval of the updated Old Town Floodplain Map, and the application of City Code 10-19(b) to this floodplain map. _________________________________________ Civil Engineer III _________________________________________ Civil Engineer III _________________________________________ Director, Civil Engineering _________________________________________ Interim Deputy Director Water Engineering Floodplain Map Approval By signature, the Utilities Executive Director has determined the Mulberry-Riverside Drainage Improvements Project at the intersection of Mulberry Street and Riverside Avenue of the Old Town Basin flood risk area does not diminish the purpose and objectives of the existing master plan and does address the disposition of stormwater runoff in the basin. The floodplain update and mapping will be kept on file (as stated above) in the office of the Utilities Executive Director upon approval. APPROVED BY: _____________________________________________________________________________ Fort Collins Interim Executive Director, Utilities Date DocuSign Envelope ID: 6C2F2FF7-D862-4735-92C2-4A651831D4B3 June 8, 2020 June 8, 2020 June 8, 2020 June 8, 2020 June 10, 2020 DocuSign Envelope ID: F858FCD5-309F-49EF-AB74-970088BBD229 Old Town Floodplain Poudre River RIVERSIDE AVE COWAN ST E MULBERRY ST E MYRTLE ST ENDICOTT ST LESSER DR Printed: 11/18/Map 2019 B . All are floodplain approximate. boundaries This Agency information (FEMA) Flood is based Insurance on the Federal Rate Map Emergency (FIRM) and Management the City of Fort that the Collins referenced Master Drainageway property will or Plans. will not This be free letter from does flooding not imply or damage. City Designated A property Floodplain not in the may Special be damaged Flood Hazard by a flood Area greater or in a than not shown that predicted on the map. on the This map map or from does a not local create drainage liability problem on the part that results of the City, from or reliance any officer on this or employee information. thereof, for any damage Moderate Risk City - Areas Floodplain of City 100-Moderate year floodplain Risk may (sheet include: flow) with average depths of less than 1 foot. FEMA - Areas Floodplain of FEMA 500-Moderate year floodplain Risk may (FEMA include: Zone X-shaded). - Areas average of depths FEMA 100-of less year than floodplain 1 foot. (sheet flow) with - Areas protected by levees from the 100-year flood. City - Areas Flood of City Fringe 100-- May year Include: floodplain including ponding areas and sheet There flow areas is a 1% with annual average chance depths that of these 1-3 feet.areas will be flooded. FEMA - Areas Flood of FEMA Fringe 100-- May year Include: floodplain (FEMA Zones A, AE, AO, and AH) There is a 1% annual chance that these areas will be flooded. High Risk City fastest Floodway velocities. - Area of 100-year floodplain with greatest depths and FEMA fastest Floodway velocities. - Area of 100-year floodplain with greatest depths and 0 62.5 125 250 375 500 Feet Old Town Floodplain Poudre River RIVERSIDE AVE E MULBERRY ST COWAN ST E MYRTLE ST ENDICOTT ST LESSER DR COLORADO ST Before Project: After Project: in Local areas drainage outside of problems FEMA and may City still mapped exist 100-year and 500-year floodplains. DocuSign Envelope City ID: 6C2F2FF7-F858FCD5-Flood D862-309F-4735-49EF-Risk 92C2-AB74-4A651831D4B3 970088BBD229 Map - Detail B Old Town Floodplain Poudre River RIVERSIDE AVE E MULBERRY ST ENDICOTT ST LESSER DR E MYRTLE ST E LAUREL ST Printed: 11/18/Map 2019 B . All are floodplain approximate. boundaries This Agency information (FEMA) Flood is based Insurance on the Federal Rate Map Emergency (FIRM) and Management the City of Fort that the Collins referenced Master Drainageway property will or Plans. will not This be free letter from does flooding not imply or damage. City Designated A property Floodplain not in the may Special be damaged Flood Hazard by a flood Area greater or in a than not shown that predicted on the map. on the This map map or from does a not local create drainage liability problem on the part that results of the City, from or reliance any officer on this or employee information. thereof, for any damage Moderate Risk City - Areas Floodplain of City 100-Moderate year floodplain Risk may (sheet include: flow) with average depths of less than 1 foot. FEMA - Areas Floodplain of FEMA 500-Moderate year floodplain Risk may (FEMA include: Zone X-shaded). - Areas averagewith of depths FEMA 100-of less year than floodplain 1 foot. (sheet flow) - Areas protected by levees from the 100-year flood. City - Areas Flood of City Fringe 100-- May year Include: floodplain including ponding areas and sheet There flow areas is a 1% with annual average chance depths that of these 1-3 feet. areas will be flooded. FEMA - Areas Flood of FEMA Fringe 100-- May year Include: floodplain (FEMA Zones A, AE, AO, and AH) There is a 1% annual chance that these areas will be flooded. High Risk City fastest Floodway velocities. - Area of 100-year floodplain with greatest depths and FEMA fastest Floodway velocities. - Area of 100-year floodplain with greatest depths and 0 62.5 125 250 375 500 Feet Poudre River Old Town Floodplain RIVERSIDE AVE S LEMAY AVE E MULBERRY ST E MYRTLE ST ENDICOTT ST LESSER DR E LAUREL ST Before Project: After Project: in Local areas drainage outside of problems FEMA and may City still mapped exist 100-year and 500-year floodplains. DocuSign Envelope City ID: 6C2F2FF7-F858FCD5-Flood D862-309F-4735-49EF-Risk 92C2-AB74-4A651831D4B3 970088BBD229 Map - Detail B