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HomeMy WebLinkAboutA7 y � � a RECEIVED FEB 2 7 2017 E &A CONSULTING GROUP, INC. CITY OFAMES, IOWA ENGINEERING•PLANNING•ENVIRONMENTAL&FIELD SERVICEPT OF PLANNING&HOUSING 330 NORTH 117TH STREET www.eacg.com PHONE:402.895.4700 f OMAHA,NE 68154-2509 FAX:402.895.3599 May 13, 2015 Mr. Charlie Kuester Planner Ames City Hall 515 Clark Avenue Ames, IA 50010 RE: Verizon Tower and Building on Squaw Creek 42.0170490 N, -93.6234550 E No Rise Certification E&A Project#: P2014.073.001 I .Dear Mr. Kuester, E &A Consulting Group, Inc. (E&A) has been asked to update a no net rise certification previously submitted on May 13, 2014, due to an updating mapping for the area. E&A is again evaluating the effects of constructing a communications tower and support building on the grounds approximately 440 feet east of South Maple Avenue and 790 feet south of South 4"'Street in Ames, Iowa as related to the established FEMA Base Flood Elevation (BFE). Please refer to the Vicinity Map- Exhibit A, enclosed. The current BFE at the proposed site is approximately 894.6±(all elevations in this submittal reference NGVD 29). The proposed site is in the defined floodway of Squaw Creek. Please refer to the FIRMette-Exhibit B. enclosed. The updated October 16, 2014 FIRM panel --shows no change to the previous BFE. The proposed communications monopole and support building shall be constructed in a heavily wooded area at the northern limits of the floodway. Please refer to the Site Plan-Exhibit C, enclosed. The site shall be cleared of 24 trees of varying maturity and trunk diameter. Please refer to the Tree Removal Plan-Exhibit E, enclosed. The trees to be removed provide approximately 14.39 feet (width) of obstruction to flow. Existing grade at the proposed site is approximately 888.0. �i The monopole is approximately 8 feet in diameter at the base. The support base for the building including stairs and exterior walkway is 24 feet by 35.5 feet. Please refer to the Proposed Building/Tower Elevation-Exhibit D, enclosed. The support building dimensions are 29.5 feet by 18 feet. The raised building base shall be oriented so that its narrowest dimension is perpendicular to the flow of Squaw Creek. The flow direction of Squaw Creek is west to east at this site. The monopole shall,be placed at the west end of the building (upstream). The building shall be elevated above the Base Flood Elevation by the use of reinforced concrete piers to the proposed finished floor elevation is 898.0. Twelve, 2-foot diameter piers and four, 1.33-foot diameter piers shall elevate the proposed building. All electrical and mechanical support infrastructures for the building and tower shall also be elevated above the BFE a minimum of 3 foot. E &A Consulting Group, Inc. has obtained the latest hard copy of the Flood Insurance Study (FIS) 19169CV000B, dated October 16, 2014, for Squaw Creek from its confluence with the Skunk River I Proposed Verizon Tower Site Ames,Iowa Page 2 of to its headwaters. The FIS data includes stream and water surface profiles used to interpret the Base Flood Elevation at the site. No effective FIS hydraulic model was provided to E&A. The proposed tower and building site is about 520 feet upstream of the former railroad embankment (now recreational trail) and bridge over Squaw Creek. The nearest river sections modeled in the FIS is at the former railroad embankment and near South 4t" Street. A cross section of the floodplain at River Station 9200 has total width of 3,700 feet that is below the Base Flood Elevation at that station. The 24-foot width dimension of the raised base is 0.649 percent of 3,700 feet. It is my opinion that the proposed Verizon Tower and building will cause no net rise in the Base Flood Elevation. This conclusion is reached on the basis of several conditions. The site is in a heavily wooded area that restricts flow velocity for that portion of the modeled cross section. The j wooded area is better at attenuating or storing the runoff than it is at conveying the runoff. Also, the area of flow restriction due to the constructed reinforced concrete piers will be offset by the removed trees. Another reason for concluding that this project will result in no net rise of the BFE is that the encroachment length (24 feet) as compared to the overall length (3,700 feet) of the modeled cross section is very small —less than 0.65%. The ground elevations around the building perimeter will remain at the existing elevations and a negligible storage volume may be lost. Another characteristic of this site is its spatial relation (upstream and off channel) to the former railroad embankment and bridge. This railroad infrastructure creates an ineffective flow area outside of the Squaw Creek channel bridge section. Should you have any questions about this investigation and conclusion, please contact me at 402- I 895-4700 or paonzales0eacg.com. Thank you for your time and consideration. i Sincerely, ��ee��a�uou¢�sav®vriv E &A CONSULTING G UP `o��vo�oQQI��ESS°1p�y9�o�®���' °° 00 v� WA PAUL J. z _ ®� o g GONZALES o E 00 Paul J. Gonzaj s, P , CFM > o° No.1958s Project Manager ���®®o�°°°°°°°°°°°o° ®�®°vOvvo ooa �Ae�ve�°°°°a Enclosures i C � EXHIBIT "All a1 i • 1dS } g��"r m �;K jlE+ l g� ✓ i "1 ® {= JV' t,'tu' �-• 4�"11 ;r `J Y.t 14 , y r 1r i I � � 4 fit$,�' p ..'f•' � �. "` ,� I. ... u r--7s c <t �E) f J l �_ � SQUAW G«RED i E &'A CONSULTING GROUP, INC. Engineering•Planning•Environmental&Field Services VERIZON TOWER SITE e/®a 330 North 1 17th Street Omaha,NE 68154 Phone:402.895.4700 Fax:402.895.3599 EXHIBIT"A" Engineering Answers Job No.: P2014.073.001 Date: 2015/05/13 AMES,STORY COUNTY,IOWA Drawn by: BJW I Scale: NA Sht: 1 of 1 Brad Williams 5/1312015 9:22 AM K:\Projects\2014\073\p01\Plans\SITE_AMES_OOO.dwg EXHIBIT 11611 PROJECT SITE � w a Y MAP SCALE 1" 500' m G O 250 0 500 1000 S 4TN ST y FEET 8 4TH 8T ME r STONEHAVENDR m Tx x7 PMEL0163F s r I FIRM 735000 FT , '� r s '" a„ ?",.. s.x _ z r s � z. � -� d n I FLOOD IHSURANCERATE.MAP STORY COUNTY r �! IOWA_ v D (AND LNCORPORATED AREAS) sX I PANEL1000F$00 (SEE M*MDE%FORF"MULAYOUn Z V SQIInM. Miff _ 1 01 P FIL•BA.SEl21NE ,ems m=�� " " T,' � X I /bflm DSUwa-M Olep Mvrtbr[A - MRx Wm J .F tlaf;de �d ) �� � Oamm'mM NWnUar *a+n b�N.IquM Oe MAP NUMBER PROFREBASELINE li ® 4 1910'C0163F MAP REVISED t m ! OCTOBER19,2014 U 1 �1 I E &A CONSULTING GROUP, INC. Engineering•Planning•Environmental&Field Services VERIZON TOWER SITE e©a 330 North 117th Street Omaha,NE 68154 Phone:402.895.4700 Fax:402.895.3599 EXHIBIT"BD Engineering answers Job No.: P2014.073.001 Date: 2015/05/13 AMES,STORY COUNTY,iOwA Drawn by: BJW I Scale: NA Sht: 1 of 1 Brad Williams 5/13/2015 9:22 AM K:1Projects1201410731p011Plans1SITE_AMES_000.dwg EXHIBIT"D" U� ' /—Parosw a'wvmnc oon ? Itl�£.i21 'a x aeon wv7tuws p m 5� J { m O l•F .� Ea.' AU rma.a _ 75 m a ` ,3 EXHIBIT"E" Z� I, a� IN Z 'I w as9 i B 20 1 inch=20 ft UTILITIES: THE LOCATION OF THE UTILITIES INDICATED ON THE PLANS ARE TAKEN ...._. .. ..r _ FROM EXISTING PUBLIC RECORDS AND ARE APPROXIMATE LOCATIONS THE EXACT LOCATIONS OF ALL UTILITIES MUST BE ASCERTAINED IN THE ppp FIELD.IT SHALL BE THE DUTY OF THE CONTRACTOR TO DETERMINE WHETHER ANY ADDITIONAL FACILITIES OTHER THAN THOSE SHOWN ON THE PLANS MAY BE PRESENT. _ II I Proposed Power Pole wlTansformerbyUtility TREE REMOVALS o o- r Ir'-r' I i, Company r-£s QTY SIZE(CAL.) COMMON NAME 2 2" HACKBERRY �«i Proposed Overhead Secondary 3 3" HACKBERRY Power.(Contractor shall 4 4" HACKBERRY a s __ ' coordinate connection emh utility SAVE 22'WALNUT v company,Approx.Length=10� _ 1 6" HACKBERRY Proposed verizon Wireless 1 8" HACKBERRY x 11-6•X 29'-5';shelter 1 28" HACKBERRY 8 Steel Platform 5 4" BOXELDER 1 5" BOXELDER t a 1 30" BOXELDER 1 12" WALNUT 1 22" WALNUT 3