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5A - Consideration of a floodplain development permit for 1235 Mariposa Ave (LUR2008-00103) CITY OF BOULDER PLANNING BOARD AGENDA ITEM MF,E`I'ING DATE: February 5, 2009 AGF~NllA `TITLE: Public healing and consideration of a floodplain development pein~it to construct a fence within the flood conveyance cone and high hazard zone of Bluebell Canyon Creek at 1235 Mariposa Ave.(case number LliR20U8-001 U3), as set forth in Section 9-3-4, "Regulations Governing the Conveyance Zone", Section 9-3-5 "Regulations Governing the High Hazard Zone" and Section ~-3-6, "Floodplain Development Permits," Boulder Revised Code (B.R.C.) 198I. ApplicantJOwner: Beth Pommer/Richard Geesaman RF.t~UES'I'ING DEPARTMI:N`T: Planning and DevclopYS~ent Services Ruth McI Ieyser, Executive Director of Community Planning Maureen Rait, Executive Director of Public Works David Driskell, Deputy Director of Community Planning Jeff Arthur, Engineering Review Manager Katie Knapp, Civil L:ngineer II, Presenter OVERVIEW AND MEETING OBJECTIVES: "i•he applicant is applying for a floodplain development permit to construct achain-link fence along the northern property line of 1235 Mariposa Ave. within the flood conveyance zone and high ha:card zone. Statt~ finds that the applicant has met the requirements outlined in B.R.C., Section 9- 3-4, "Regulations Governing the Conveyance lone", Section 9-3-5 "Regulations Governing the High Hazard Zone" and Section 9-3-6, "Floodplain Development I'ennits." Staff recommends the approval of the floodplain development permit. Define the steps for Planning }3oard consideration of this request: I . Hear Applicant and Staff presentations ' 2. Nold Public Healing 3. Planu~ing Board discussion 4. Planning Board take action to approve, approve with conditions or deny - '.l _ ~ , PURPOSE: The purpose of this item is to review and take action on a floodplain development permit to construct approximately 100 linear feet of 4-foot high chain link fence within the flood conveyance zone and high hazard zone along the northern property line of 1235 Mariposa Ave. (See vicinity map in Attachment A). RACKGROUNU: The property at 1235 Mariposa contains a single family house and an in-ground swimming pool. Section 9-9-19 B.R.C. and the lnternational Residential Code (IRC, 2006) require fences around swimming pools. The existing swimming pool has been enclosed by a chain link fence since it was constructed in 1959. The applicant discovered that this fence was not constructed along the property line, but extended further north onto the neighboring property at 501 13t~' St. The applicant would like to build a new fence because there are concerls that the property owner of 501 13`x' St. could remove the existing fence which would make the swimming pool out of compliance with the city land use regulations and the adopted building code. A portion of the proposed fence location is within the flood conveyance zone and high hazard zone for Bluebell Canyon Creek and within the wetland buffer. The applicant applied for both a wetland permit and a floodplain development permit. "I'he wetland permit (Attachment B) was approved on August 8, 2008. Because the proposed fence would impact wetland buffer areas and not wetland areas, a simple wetland pernit applied. Simple wetland permits are final upon issaance and are not subject to Planning Board call-up. The floodplain development pernit (Attachment C) was applied for on November 10, 2008 and issued on December 4, 2008. Floodplain development permits for projects that are within the flood conveyance zone can be called-up by Plaiv~ing Board or appealed to Plamiing Board by an aggrieved party. During the December 18, 2008 Planning Board meeting, the floodplain development permit was appealed by'I'om Winter- of 501 13°i St. (See written appeal in Attachment D). ANALYSIS: In reviewing floodplain development pernits for projects within the flood conveyance zone and the high hazard cone, the criteria of Section 9-3-6 "}~'loodplain Development Permits", Section 9-3-4 "Regulations Governing the Conveyance Zone" and Section 9-3-5 "Regulations Governing the Iligh Hazard lone" B.R.C. are considered. The criteria for the consideration of a flood permit and the staff's rationale and f ridings as to why those standards have been satisfied for this application are listed below: Section 9-3-6 "Floodplai?i llevelopmeait Permits" Criteria: 1. The ei'fects upon the efficiency or capacity of the conveyance zone and high hazard zone; The existing Bluebell Canyon Creek channel is heavily vegetated with several fences both along and crossing the creek in the vicinity of the proposed project. The proposed fence will be replacing a similar fence and will be farther up the bank tiom the strewn channel. There are many factors that influence the hydraulic capacity of a flood channel including: size of the channel, slope, and the rougluless of the channel surface. When the flood channel is analyzed, a channel roughness (Manning's coefficient) is chosen to account for vegetation, buildings, fences and other items on the surface. The addition of the proposed chain link fence within the existing, heavily vegetated channel and parallel to the flow of the flood waters would not result in a change to the surface roughness used for the floodplain analysis. Therefore, it was determined that the proposed fence would have no negative effect upon the efficiency or capacity of the conveyance zone or high hazard zone. The hydraulic impacts of the proposed fence were also considered by David Love, T'.C., of Love and Associates, who detern~ined that the construction of'the fence would have no adverse impacts on the 100-year floodplain and that the project meets all regulatory requirements of the City's floodplain regulations. (Attachment E). 2. The effects upon lands upstream, downstream, and in the immediate vicinity; As stated above, it was determined that the proposed fence would have no negative impact on the efficiency or capacity of the flood channel. `therefore, the proposed fence would have no negative impact on lands upstream, downstream and in the immediate vicinity cif the project. 3. The effects upon the one hundred-year flood profile; If a flood channel is .i~egativcly impacted and the capacity is reduced, the result is an increase in the flood water elevation, which cor•esponds to an impact to the 100-year flood profile. As stated above, it was de±ennined that the proposed fence would have no negative impact on the efficiency or capacity of the flood channel Therefore, the proposed fence will not affect the 100-year Hood profile. 4. The effects upon any tributaries to the main stream, drainage ditches, and any other drainage facilities or systems; 'I•he proposed fence will not cross any drainage facilities or drainage systems, but will be located along the edge of and parallel to Bluebell Canyon Creek. Therefore, it was determined that the proposed project would have no adverse affect upon any tributaries to the main stream, drainage ditches, and any other drainage facilities or systems. 5. Whether additional public expenditures for flood protection o~• prevention will be required; 'T'he fence is located on private property, no additional public expenditures for flood protection or prevention will be required. 6. Whether the proposed use is for human occupancy; Tl~e proposed fence is not a structure intended for human occupancy. 7. The potential danger to persons upstream, downstream, and in the immediate vicinity; ns stated above, it was determined that the proposed fence would have no negative impact on the efficiency or capacity of the flood channel. The fence will also be constn~cted to resist the forces of a flood. 'I~hcrefore, the proposed fence would not increase the potential danger to persons upstream, downstream and in the immediate vicinity of the project. 8. Whether any proposed Changes in a watercourse will have an adverse environmental effect on the watercourse, including, without (imitation, stream banks and streamside trzes and vegetation; The project does not include any grading or significant vegetation removal. The app}icant also received a wetland permit for the project and will be using Best Management Practices during the construction of the fence. Therefore, the project was determined to have no adverse environmental effect on the watercourse. • 9. Whether any proposed water supply and sanitation systems and other utility systems can prevent disease, contamination, and unsanitary or hazardous conditions during a flood; There are no proposed utility systems being considered, therefore this criteria does not apply. 10. Whether any proposed facility and its contents will be susceptible to flood damage and the effect of such damage; The proposed fence will be designed to resist damage during a flood event. 11. Thy relationship of the proposed development to the Boulder Valley Comprehensive Plan and any applicable floodplain management prvgrams; The proposed fence would be in compliance with the Boulder Valley Comprehensive Plan and any applicable floodplain management programs. 12. Whether safe access is available to the property in times of flood for ordinary and emergency vehicles; The proposed fence will not change access to the property. There is already an existing fence around this portion of the property. l3. Whether the applicant will provide flood warning systems to notify floodplain occupants of impending floods; No flood warning systems are proposed or requirc;d for this project. 14. Whether the cumulative effect of the proposed development with other existing and anticipated uses will increase flood heights; "I'he proposed project is consistent with the other existing uses in the area and was determined to have no impact on the 100-year floodplain as stated above- Therefore, the proposed fence will not result in an increase to the flood heights. 15. Whether the expected heights, velocities, duration, rate of rise, and sediment transport of the floodwaters expected at the site will adversely affect the development or surrounding property. As stated above, it was detc;z7nined that the proposed fence would have no negative impact on the efficiency or capacity of the flood channel. Therefore, the proposed fence wi}1 not result in a rise to the 100-year flood elevation, increase ve}ocities, duration, rate of rise or sediment transport of the floodwaters. Section 9-3-4 "Regulations Governing the Conveyance Zone" Criteria: l.. No person shall place any structure in the conveyance zone that will result in any rise in the elevation of the one hundred-year flood; If a flood channel is negatively impacted and the capacity is reduced, the result is an increase in the flood water elevation . ~s stated above, it was determined that the proposed fence would have no negative impact on the efficiency or capacity of the flood chazlnel. Therefore, tl~ze proposed fence wil l not result in a rise in the l UO-yeaz- flood elevation. 2. No person shall place any obstruction in the conveyance zone, except a device reasonably necessary for flood management if the device is designed and constructed to mininuze the potential hazards to life and property. Section 9-16 B.R.C. "Definitions" includes tl~ze following: "Obstruction" means any item or material not constituting a moveable object in, along, across, or projecting into the floodplain that might impede, retard, or change the direction of a flow of water, either by itself or by catching or collecting debz-is ca~Yied by such water, in a way that the city mama eg r determines would increase the flood hazard to adjacent pro~~erties. (floodplain) Based on the determination that the proposed fence will have no adverse impact on the 100- yearfloodplain, it was determined that the proposed fence would not increase the flood hazards to adjacent property owners and therefore is not considered to be an obstzlzction. Section 9-3-5 "Regulations Governing the ITigh Ilazard Zone" Criteria: 1. No person shall change the use of an existing structure intended for human occupancy from a nonresidential use to a residential use or use as a schoc?l, daycare center, hroup borne, residential care facility, or congregate care facility in the high hazard zone; No change of use is proposed, therefore this eziteria is not applicable. 2. No person shall establish any new parking lot for motor vehicles in the high hazard zone; No new parking lots az•e proposed. 3. No person shall establish an,y campground in the high hazard zone; No campgrounds are proposed. 4. No rerson shall construct or place any new structure intended for human occupancy in the high hazard zone; No new stz•uctures intended for humman occupancy are proposed. S. Nu person shall expand, enlarge, or make a substantial modification or substantial improvement to any existing structure intended f'or human occupancy in the high hazard zone. The project does not include any work on stzlzctures intended For human occupancy. Staff concluded that the application met the reyuiremez~ts of the criteria of Section 9-3-6 "floodplain Development Permits", Section 9-3-4 "Regulations Governing the Conveyance Lone" and Section 9-3-5 "Regulations Govez-ziing the High Flazard Zone" B.R.C. Therefore, the floodplain development permit was issued. Staf'f's conclusion is that the applicant satisfied the requirements of Section 9-3-6 "Floodplain llevelopment Permits", Section 9-3-4 "Regulations Gvver-ning the Conveyance Zone" and Section 9-3-5 "Regulations Governing the I-Iigh Hazard Zane" S.R.C. and that the t7oodplain development permit should be approved. PUBLIC COMMENT ANll PROCESS: Conveyance zone floodplain development permits require public notification upon issuance of the permit. A notice was published in the newspaper on December 7, 2008. All notice requirements of Section 9-4-2, B.R.C. 1981 have been met. Public comments regarding the floodplain development permit may also be received through public healing. During the December l 8, 2008 Planning Board meeting one resident voiced opposition to the issuance of the floodplain development pernit and subsequently provided a written request to appeal the issuance of the floodplain development permit. On January 29, 2009 additional information was received stating their opposition to the issuance of the floodplain development pernlit. The written appeal and brief in Opposition to the floodplain development permit is included in Attachment D. A letter was also received in support of the proposed project nn January 21, 2009 Ez-om the neighboring property owners at l 333 Mariposa Ave., 1303 Mariposa Ave., and 500 13`x' St. (Attachment E) STAFF RECOMMF,NllATION: Starf recommends that the Planning Board adopt the following motion: The Plaln~iug Board approve the floodplain development pernit attached to this memorandum as Attachment C and adopt this memorandum as the findings of fact. Approved by: Ruth NlcHeyser Executive llirector of Community Planning ATTACHMENTS: A. Vicinity map. B. Wetland permit C. Floodplain Development Pernit D. Request to appeal floodplain development pernit E. Letter from David Love, P.F., dated August 4, 2008 ATTACHMENT A Cit ofi Boulder Vicinit Ma r._ ~ - Subject Area i- ~ - i T. `-I ~ l~ 501 13TH ST / / , li `l/ `t ,.l/,,.%, ,1~, ,l/~, ~ `til/`l/~,l/` . lip ~Q(jl// ~/j(~~ /lj`//~/ %`lj~/`~/`'i 'jam%~/j\/` ~ ~ ~ li / ,//`.//~li / C ~i ! `l`l/`li`t` ! , `i`. ,~i/~%!~l%(~C ~l~ l/`li lip!/.~l/li~l/.i`l ~iil `lili` ¦ Legend PO~~ Fences 1235 MARIPOSA AV v ~ ~ ¦ Existing Fence ~ Proposed Fence ® Bluebell Creel< - ®Building Footprint High Hazard Flood Zone ® Conveyance Flood Zone Location: 1235 Mariposa Ave % City of , Review Number: LUR2008-00103 Review Type: Flood pla i n Review 1 ~ ~ ~ ~ The informaton depicted on this map is provided wlo Analysis as graphical representation only. The City of Boulder provides no warranty, expressed or implied, as to 1 inch = 3 d feet the accuracy and/or completeness of the information contained hereon. CITY 4F BOULDER ATTACHMENT B Aria ~ Planning and Development Services .r1 i~~.'~a~ I'/ 1739 Broadway, Third Floor • P.O. Bax 791, Boulder, CO 80306-0791 phone 303-441-1880 fax 303-441-3241 web boulderplandevelop.net Wetland Permit Date Issued: 8/20/2008 Expiration Date: August 20, 2011 (Pursuant to Subsection 9-3-9(k}, B.R.C. 1981) Permit Number: LUR2008-00073 Contact Information BETH POMMER 750 LINCOLN PL BOULDER, CO 80302 Project Information Location: 1235 MARIPOSA AV , . _ ~ LegaE Desc'ription` LOT 1 BCK 6 BELLEVUE PARK REPL AT 001235 MARIPOSA AV BOULDER Description of Work: Wetland Permit for installation of chain link fence Conditions of Approval ' ~ The proposed project/activity is approved on the basis that it satisfies applicable requirements of Chapter . 9,,-3-9, "Wetlands Protection," Boulder Revised Code 1981. Other wetland requirements as set forth in Chapter 9-3-9 which are not specifically outlined in the conditions of approval below remain applicable to this projecUactivity. The project shall be completed in accordance with the wetland permit application materials submitted on August 1, 2008: Best management practices shall be applied to all phases of the project and shall conform to the requirements of the "City of Boulder Wetlands Protection Program: Best Management Practices" adopted July, 1995; and "City of Boulder Wetlands Protection Program: Best Management Practices - Revegetation Rules" adopted July, 1998. After the completion of the project, please call Katie Knapp, the Floodplain and Wetland Administrator, at 303-441-3273 to schedule a site inspection- Please references the case number (LUR2008-00073). Inspections To schedule an inspection, call 303-441-3280 and refer to your permit number {LUR2008-00073). Final Wetland Mitigation insp G' _ Cl ' ATTACTII<'iF.N`I' C CITY OF BOULDER •r~ ~ Planning and Development Services , + ~ ~ 1739 Broadway, Third Floor P.O. Box 791, Boulder, CO 80306-0791 ~y-~,~_ Nhon,G JV3-4'+1-IOOV = rax 303-441-3241 web boulderplandevelop.net Land Use Review Floodplain Development Permit Date Issued: December 4, 2008 Expiration Date: December S, 2011 (Pursuant to Subsection 9-9-9(e), B.R.C. 1981) Permit Number: LUR2008-00103 Contact Information RICHARD GEESAMAN 1235 MARIPOSA AV BOULDER, CO 80302 Project Information Location: 1235 MARIPOSA AV Legal Description: LOT 1 BLK 6 BELLEVUE PARK REPL AT 001235 MARIPOSA AV BOULDER Description of Work: 100 feet of chain link fence 4 feet in height. See LUR2008-00073 Type of Floodplain Permit: Floodplain Review W/O Analysis Creek Name: Bluebell Canyon ' . - Flood Protection Elevation: Not applicable . Conditions of Approval The proposed projectlactivity is approved on the basis that it satisfies applicable requirements of Chapter 9-9, "Floodplain Regulations," Boulder Revised Code 1981. Other floodplain requirements as set forth in Chapter 9-9 which are not specifically outlined in the conditions of approval below remain applicable to this project/activity. The fence shall be securely anchored to resist damage and washing away as debris during flooding events. . The applicant shall obtain a site inspection and approval from the City of Boulder Floodplain and Wetlands Coordinator upon completion of the project. Inspections To schedule an inspection, call 303-441-3280 and refer to your permit number (LUR2008-00103). Final Floodplain Inspection ~ • s City of Boulder Planning and Development Services Center ~ FLOODPLAIN CIEVELOPMENT PERMIT Date: Case No: PM / E_U APPLICATION . Project address: ~ ~ ~ cJ ~t~ I I~JOS0. ~VP Lot: j Block: (D Qt.•i. ~t ~ V' C~ ~-U Z-- Subdivision: ! ~ 1 Legal description: I • ~ • Property owner(s): ~ h ~ •P ~ ~iw1Gc r/~ Mailing address : ~ Z~ / f~ qt' ?tPt~S~ ~~2 . Telephone number: (~7j) ~~-~G~,_ ~~~~~2~'. ~C~ 2 Fax number: ( ) - E-mail address: j S~ ature of grope er(s) listed above""': "Attach additional forms if there are additional property owners. This I permit appl?cation well not be accepted w?thout the signature of all ` property owners. The signature is an acknowledgement and consent to >~r~~ J~ this floodplain development permit application. ~ G,-..~? ,fJ Name: N1 • ~7 ~ T~0 cM tM~~ Mailing address: `7 ~ U ~ t ~ CU I-"~ Telephone number. (~03) Z-~i 4~ ~1.L ~ ~ Pp t~? ~rn e~Co C ~•-U L ~ c-n~--, Fax number: ( ) - E-mail address: ~ ' 7? New Structure ? Addition to Structure E>' Residential ?Non-residential ? Grading ? Change in Watercourse ~7escription of work (i.e., First floor addition of 750 square feet, OR construction of bike path, etc.1: L~ U I i ~~eGirr~ v~ c'_t-zcl~ti Li ?1k -(`tti•~~~~ ~r - ~ r~'"~ 6~e t Creek: ? Four Mile Canyon ? Wonderland ? Elmer's ? Two Mile Canyon ? Goose ? Sunshine ? Boulder ? Gregory Canyon ~luebell ? King's Gulch C3 Skunk ? Bear Canyon ? Vieie Channel ? Dry Creek No. 2 ? South Boulder Flood Zone: ? 100-Year (flood elevation defined) ? 100-Year (shallow flooding) ? Conveyance ? High Hazard City of Boulder Planning and Development Services Center 1739 Broadway, third floor Boulder, CO 80302 ~ Phone 303-441-1880 i ' • ~ - • - ~ • ~ • ~ - • Water surface elevation defined? : ~ Yes ? No If yes: Upstream X-section number: Down(s~tream X-section number: Predicted 100-year water surface elevation: ~ - l ~ ~ ~ ~ I ~ I If no: What is the location of the highest grade adjacent to the structure? : i ~l 1 L'~ ~~ar S~~ru ~ J Elevation of highest adjacent grade: ti~ / I^2 r t ~ c SHADED AREAS APPLY TO ADDITIONS ONLY Construction Year: Approximate year(s) any previous addition(s) were buifL ,'"`Existing habitable floor area: "Habitable floor area of_ proposed addition:' . Are you applying for a floodplain variance? : ? Yes ? No ' Has the structure had any previous approved floodplaini` variances? : ? Yes ? No Habitable floor area does not include floor area of unfinished garage or crawlspace. - ~ All floodplain development permit applications must include the following: ? Location map -Clearly show project location, all adjacent streets, subdivisions, etc. ? Development plan -Clearly show the 100-year floodplain, conveyance, and high hazard zone boundaries as they relate to the proposed project site. ? Complete detailed description of the proposed project including a discussion of the impacts to the floodplain as required by g-3-6(c) Floodplain Development Permits, BRC, 1981. The following additional materials may also be required: ? Engineering report completed and stamped by a licensed Colorado Professional Engineer which includes: ? Hydraulic Analysis (HEC-2 study, hard copy and disk copy} ? Structural analysis ? Determination that the proposed construction or development is in accordance with the City of Boulder Floodplain Regulations and that no rise in the water surface of a 100-year flood will occur due to the proposed construction or development. ? Flood proofing details ? Velocities of flood flows and flood depths across the property ? Other ~ ~ • ~ ~ ' ~ • Please refer to the Schedule of Fees for current fee information. ~~r~r:~cll~ll~:N~r n MEMORANDUM 'lO: Planning Board FROM: Katie Knapp, Civil Engineer, Floodplain and Wetlands Permitting DATE: December 4, 2008 SUBJECT: Call Up Item: 1235 Mariposa Floodplain Development Permit (LUR2008-00103) This decision may be called up before Planning Board on or before December 18, 2008 A Floodplain Development Permit was approved by Planning and Development staff on December 4, 2008. The project involves the construction of a chain link fence within the conveyance flood zone of Bluebell Creek. The proposed project involves construction of approximately 100 linear feet of 4-foot high chain link fence along the northern edge of the property. The applicant has demonstrated that the project will not adversely impact the floodplain or cause a rise in the floodwater elevation during the 100-year flood event. This floodplain development permit was approved by Planning and Development Services staff on December 4, 2008, and the decision maybe called up before Planning Board on or before December 18, 2008. There is one Planning Board meeting within the 14-day call-up period on December 18, 200.3. Questions regarding this wetland permit should be directed to Katie Knapp iii Planning and Development Services at 303-441- . 3273 or knappk@bouldercolorado.gov. ~ L!_ V f 7 Fz vt~t 12 ~ diA ~ ~ ~ P a S ~ 1 ?..f ct A~.~ S 1~'t~ ~t 'G-c~"has 9tL- ~ ~ f ~ 5'?'~ZL t1 ~ ~ ~ ~ Knapp, Katie from: Tom Winter [tom@freeskier.com} Sent: Thursday, December 18, 2008 6:54 PM To: Knapp, Katie Cc: Joe de Raismes Subject: Appeal, Fence at 1235 Mariposa Katie: This email will constitute an appeal to the decision to approve the installation of a fence in the conveyance zone at 1235 Mariposa, per the Planning Board meeting held tonight. Thank you for the consideration, and when our council, Toe de Raismes is back in action, he will continue to represent us in this matter. Please keep both him and myself advised of any further action you or the City plans to take in this matter. Sincerely yours, Tom Winter i . _;1.1. - ~ ,I ,'I ~ 0 ENTRY Or APPEARANCE AND BRIEF IN OPPOSITION TO FLOODPLAIN DEVELOPMENT PERM)[T To: Plazlrzing Board From: Joseph N. de Raismes Re.: Opposition to Obstruction in the Conveyance at~zd High Hazard Zone -Call-up of Geesaman Flood Pernzit (1235 Mariposa) Date: January I5, 2009 I represent flileen and Tom Winter in protesting the chain link fence proposed by Beth Poznmer on a portion of her parents' (the Geesamans') property boundary, blocking a portion of the Bluebell Canyon Creek gorge in this location. The Winters recently purchased the adjoining home across the Bluebell Canyon Creek drainage at SO 113`x' Street and discovered a number of problems, including a mis-located fence on their property about half way up the side of the Gorge opposite the Winter home. The attached photo, Exhibit A, shows the existing fence in a dark tone, highlighted by the recent snowfall. The Winters intended to remove the fence, in order to clear the floodway, the wildlife corridor and the view obstz-ucted by the fence. They then heard from the Geesamans that this would jeopardize the safety of their swimming pool and its compliance with zoning regulations. The Winters agreed to hold off in demolishing their fence, until this proceeding was begun which jeopardizes the values that they want to protect. This is a very steep site, with an abnipt watercourse draining the Chautauqua mesa to the west. The flash-flood danger is significant, and the eroded gorge shows the effects of past floods. The floodplain, the conveyance zone, and the high-hazard zone are coincident in this location with the top of the gorge. The Geesamans now propose building a new fence to their property line, just south of the existing fence, in the gorge, and they reject the Winters' argument that any fence should be set further back, on top of the gorge, slightly nearer the Geesamans' house. Exhibit B shows the distance between the top of the gorge (in purple) and the Gcesaman Douse. The Winters have no objection to the fence; even an ugly chain link fence, and the view is not an issue in these proceedings. But if anyone is to have a fence, it should not be located in the conveyance and high hazard zones if the functional need to protect the Geesamans' swimming pool can be met in another way. This is the most regulated portion of the floodway, the area where any obstruction should be avoided, as a matter of principle. In fact, tire. only r r~uu:cr.t for the prohosc~l fence li~cati<~n i~ that it delincatc5 the property boundary. if the fence followed the contour of the gorge, there would be no objection, but the property boundary encroaches into the gorge, and so does the fence. Does the delineation of property ownership boundaries trlunp the floodplain regulations entirely, or do broader community values prevail to prevent encroachment on the conveyance/high hazard zone? That is the question that the Winters as}c the Planning Board to consider in this call-up. City staff has taken the position that obstructions are permitted in the conveyance zone so long as they do not create a rise. The ordinance is more restrictive. Under Section 9-3-4, `'Regulations Governing the Conveyance Zone," structures are permitted that do not create a ri~c, but "obstructions" are not: In the conveyance ronc, the following standards apply: (a) The provisions of section 9-3-3, "Regulations Governing the Floodplain," B.R.C. 1981. (b) The provisions of section 9-3-5, Regulations Governing the High Hazard ~onc," B.1t.C. 1981, if the land is also located in the high hazard zone. (c) .111 uses allowed under the provisions of section 9-3-3, "Regulations Governing the Ploodplain," B.R.C. 1981, if they are not prohibited by the underlying zoning district or any ordinance of this city, maybe established except that no person shall establish or change any use that results in any rise in the elevation of the one hundred-year flood. (d) A19 structures allowed under section 9-3-3, "Regulations Governing the Floodplain," B.R.C. 1981, may be established except that no person shall: (1) Place any structure in the conveyance zone that will result in any rise in the elevation of the one hundred-year flood; or )Place any obstruction in the conveyance zoaie, except a device reasonably necessary for tood management if the device is designed and constructed to rninirnize the potential hazards to life and property. (e) No person shall can•y out any other development t11at results in any rise in the elevation of the one hundred-year flood. (emphasis supplied) The term "obstruction" is defined in Chapter 9-16: "'Obstniction' means any item or material not constituting a moveable object in, along, across, or projecting into the floodplain that might impede, retard, or change the direction of a flow of water, either by itself or by catching or collecting debris can-ied by such water, in a way that the city manager determines would increase the flood hazard to adjacent properties." A chain link fence is a classical obstruction, which will gather debris and prevent passage of debris and floodwaters and, with adequate force, might itself become debris in an area of high flood velocities like this. Human beings and other animals could be trapped and injured by being swept into the fence. Since my clients are more in danger from the flood than the Geesaman family, whose house is located outside of the floodplain, we particularly object to any obstruction that may redirect flood waters or debris onto the Winter property, as we believe this fence will do. Attached to this memo is an excerpt from the City of Boulder's floodplain map, Exhilbit >l$, with the floodplain/flood conveyance area and high hazard zone in purple and the property lines in red. As the Board will see, the proposed fence cuts off a bend in the chan~~el, forcing the water to the north, away from the Geesamans' house and toward the Winters' house once the chain links become clogged with debris from upstream. It is for that very reason that we propose removing the existing fence on our property aild that we oppose the proposed new fence on the property boundary. Exhibit ~ is an additional photo of the existing fence, showing dramatically how clogged the fence is already. Imagine similar debris from upstream added in, scoured out by a big flood. Staff has taken the position that since a fence is a defined "structure" pursuant to the 9-16 definition, it must not be an "obstruction." But notice that the code, in Section 9-3-4, treats "obstructions" as a subset of "all structures." Asz obstruction is a structure that obstructs. 'thus, it is incumbent on the applicant, as the "proponent" of this floodplain development permit, to prove that this particular proposed structure in the floodway does not constitute an "obstruction," even though it appears from the map to redirect larger flood flows toward the Winters' home. This, the applicant cannot do and has made no effort to do. The last objection will be that other fences already obstruct the drainages in Boulder, and specifically the Bluebell Canyon Creek drainage. But while that would be enough to "grandfather" a vested right to a fence, it caiuiot justify a new fence, which is what is being requested. And the negligence of past fencing, in many cases antedating the current floodplain development permit requirement, carulot excuse negligence now. The conclusory opinion of the City's loaned expert, Dave Love, is in your packet. You will notice that he makes no mention of whether or not this fence is a prohibited "obstruction." Rather, he misstates the facts, asserting that the applicants "desire to move their fence," a fence that is not theirs and is located on my clients' property. He then blandly concludes that the fence: "will have no adverse effect on the 100-year flood plain [no mention of the conveyance and high hazard zones] [andJ that this project meets ail of the regulatory requirements of the City's floodplain regulations...." Accordingly, there being no evidence to refiite the Winters' concerns that the Geesaman fence constitutes a prohibited obstruction, this application must be rejected. We - - ~ c. r'' ~ - specifically request that the Plaiuiing Board find that the location of the proposed Geesaman fence could "increase the flood hazard to [the] adjacent [Winter] propert[y]" by restricting the flow in the Bluebell Canyon Creek gorge opposite the Winters' home, thus redirecting larger flood flows onto their property. It need hardly be added that it is perilous for the City to approve such an obstruction, since it could lead to City liability in case of a flood. The Winters will present expert testimony, photographs and maps at the hearing and hereby seek party status pursuant to Section 1-3-5(h), S.R.C. l 981. Very tnily ours, Joseph i de Raismes, Atty. Reg. No. 2812 Gapl.an and Earnest LLC 1800 Broadway Boulder, Co 80302 cc. 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' _4 ti . - e1'r~"!',.i, ,*.1 !`G~1. 1 Gr 1~''~l~I•1~ f ~ ~,t .'r ,Il iiylii+~ ~ r" fl ~u t\ n••-~1i . ~ 1 • ~t ~ ~ ~ r, S ~ y~ y, ? ~yl f 3 , 1 f l ! - 1 4 Ky r- '`k I r , A + _ f I *1 ~C:'r •,r..- BlueUell Cres:k 18U-degree panorama. Centcr of image looking south at Geesaman property from Winter property. Stake rear center of isnaae denotes approximate point on property lisle. (u~ J ~J u~ 1• . x ` , '1 ! ` ~ ~ X71 . 1 r,' f \ , r bf L ~ ! J "t`, fib, ~ t~ .1 _ r _ ~ ;r ~ 6 , ' ~ :T, ~ 1 ~~7' ?'~s~ .5.1 .y ( ~ ` ~ 1., \ , cam' y ~ t ~ : } ~ ~ • 't , u. _ ~ / `R ~ 1. ~Y1.~i''It t, -t1~`r d kpe,~71y ~ ;r~ ~ ~ ,.,i."(` t ~ " . _ .yE <~O'p';y~ i I'~+1. ~ fir" !~J 11 ,r ~ ~ t~~~ fr~ ~ ! 1~ ~1 P~ 'Y~a~ ~ ~ 'J \~,l 'li~,~ SA3~'!,,; ` r j, ~"1,,~ ,.t ~.`r l' ! t 1`'V rYv!'~'i1. 7 't' - ( 1` V ~ f a t. ~ + + tI~ •I; ~~\~~sj!1y ~ `,lJ~`~ l1 1`t~ 1,.~ ~.'.`t y1l~r~f ~+_jc \ .w, '"~'}~c~: .1,^ ~ r ti 1~1~r~ ~ f' f f.~ r l1t \~~rl. ~irL1c~ ~ . v. Bf ~ ~ f ,'r F~~. ~a C\°, Y~i%r ~~ft't ~e. .1 \~f ~ 1~ ~ rT ~ ..w f ~ ~ ~ '~I.' ~ rr~ 1 r r ~t i'~ 1 i 1 r ~ f H~i`.~r?~ Yyt ~ <r ~ %p. r,~.'i:,. _ %.f~ Y i~ .'i rrl~ ° r Ii ~ ~.,'1 r 1 (.~~1c:~ »y~: 'i 1?'~ a .a i 'l \1 , ` ~ _t' ~ / . 1 t l~~! y}~./ i iy l~ i IJ3~', d' ti 1 ~,y ` T,a¢ • ' ! ; . t >z ~,•\r ~ ~ ' ~ f . r \;i'~.;~I'~J' ~ ~fs~. 4jif ! )r, .1~3•~ Y~ r`! 'j' ~ .fb ~1~ • % i.. 1 v~ ~~r `~'~.1•yl 'J .l~Jp `~L~L, t q~~%~ .C 9- 1 ~ ~ ~ _ ~i r. j' may... l ~ b _ • ..~T ~ ~ir~ ~ ' . 6 ~ ~ -i.L _ p`art', , ,,a _ _ :;G.. . . _'s.. 'tite`r !t?.w r. ATTACHMENT E August 4, 2008 Ms. Katie Knapp Wetland/FloodplainManager Department of Community Developments City of Boulder P.O. Box 791 Boulder, CO 80306 Ref: 0824A - Floodplain Opinion letter 1235 Mariposa Avenue, Boulder, Co 80302 Owners: Richard and Ann Geesaman Dear Katie: At the request of Beth Pommer, the daughter of the homeowners at the above mentioned address, I have reviewed the flood situation within the Bluebell Canyon Creek floodplain for this property. I have discussed this issue with Katie Knapp and it was agreed that I could render a professional opinion on this issue and that I would not have a conflict of interest. The back property line of the house at this location is located partially in the 100 -year floodplain. The City flood maps show that the 100-year floodplain equals the Conveyance Zane which equals the high I Iazard Zone at this location. Please refer to the enclosed City flood map. The owners of 1235 Mariposa Avenue desire to move their fence further away from the cicek to their existing property line shown on the map. They propose to construct the fence of 4 or 6 fast high chain link in a similar manner as their existing fence. The fence is needed as a safety measure because they have a swimming pool in their back yard. It is my professional opinion that the construction of a new fence will have no adverse impact on the 100-year floadplain, that this project meets all regulatory requirements of the City's floodplain regulations and that a flood permit should be issued for this project. If you have any questions or require additional information, please feel free to contact me. Sincerely LOVE & ASSOCIATES, INC. By /~~~-zi-' ~ dl~~ David J. ove, P.E. cc: Beth Pommer 800 Jepson Avenue, Su'rOe 8 Louis~rille, Cdaado 80077-1873 Phase: 30ri6738T95 Fax: 303~6T3879f ATTACHMENT F , Katie Knapp January 21, 2009 1739 Broadway Boulder, CO 80306 knappk@bouldercolorado. gov Dear Ms. Knapp, As neighbors of Ann and Dick Geesaman, we would like to express our support for the issuance of the Floodplain Development Permit for 1235 Mariposa Ave. We see no reason why this permit should not go forward, and find no rational reason for its appeal. It seems to us that no matter what their reasons are for applying for this permit, it should be issued if they have made an appropriate application and have met the City's requirements. That being said, it still remains that the issuance of this Floodplain Development Permit will allow them to construct a fence nearly identical to the one currently behind their property. It is a "replacement" for the fence which their new neighbors, the Winters, have partially dismantled ~ already. There are a significant number of "grandfathered" fences crossing Iluebell Creek. We know that these can continue to be "repaired,'' no matter where they sit in or near the creek. We do not see the proposed fence as being any more significant. The fence would be essentially parallel to the creek bed and not cross it. It replaces a fence that has been there for at least as long as the Geesamans have lived in their home. David Love, awell-respected consultant and engineer, assessed the new location of the fence, asserted his belief that there would be no adverse impacts on the floodplain, and felt that ail regulatory requirements of the City's Floodplain Regulations have been met. While we had no issues with the construction of the proposed fence before, we are now confident that the fence will present no increased risk to our properties, much less to any other properties along Bluebell Creek. We firmly believe that there are no concrete reasons to deny our neighbors, the Geesamans, their Floodplain Development Permit, so that they can get on with building ~Jth~eir fence. J l 3 J~ l r i e s ~ f~---~ ~ ~ ~ i 3 ~ S~