TOWN OF TONAWANDA, NEW YORK ERIE COUNTY i,- FEBRUARY 17, 1981 federal emergency management agency federal insurance administration COMMUNITY NUMBER • 360260 OF 1., 1 Purpc:se of Study 1 ~ 2 and AcKnowledgements 1. 3 Coordj nation 2 Scope of Study 2 2 2~3 Principal Flood Problems 4 2~4 Flood Protection Measures 6 6 6 3.2 Hyd.raul.ic l\rla 8 10 10 12 Rcacl·, Detenninations 12 Floc;c1 Hazard Factors 14 F'j_ood Insurance Zones 14 oo(:l Insurance" Hate Ylap 16 i TABLE OF CONrrENTS - continued 6 ~ 0 OTHER STUDIES 17 7. 0 LOCATION OF DA1'A 17 q 8.0 BIBLIOGRAPHY AND REFERENCES '' FIGURES Figure 1 - Vicinity Map 3 Figure 2 - Potential Flood Elevation, Town of Tonawanda 1 New York 5 Figure 3 - Potential Flood Elevation, Town of Tonawanda, New York 5 Figure 4 - Floodway Schematic 13 'fABLES Table 1 - Summary of Discharges 8 Table 2 - Floodway Data 11 Table 3 - Flood Insurance Zone Data 15 EXHIBITS Ex-hibit 1 - Flood Profiles Ellicott Creek Panel 01P Niagara P~ver - Tonawanda Channel Panel 02P Tonawanda Creek Panel 03P Exhibit 2 - Flood Boundary and Floodway Map Index Exhibit 3 - Flood Boundary and Floodv-;ay Ivlap ii TABLE - continued PUBLISHED SEPARATELY: Flood Insurance Rate Map Index F'lood Insurance Rate f"lap iii FLOOD INSUP.Ji"NCF: S'l'UDY TOVJN OF TONAVJANDJ\, NF\!J YOHK 1. 1. 1 Purpose of St_udy This Flood Insurance Study investigates the exist_ence cmd severity of flood hazards in the Town of Tona\vanda, Erie County, New York, and aids in tJ1e administ-ration of the National Flood Insurance Act of 1968 and thr: Flood Disaster Protectior Act of 1973~ This study will be used tc convert rronavJanda to the regular program of flood insurance by the Federal Insurance Administration (FIA}. Local and planners wil_l_ use this s·tudy in their efforts to promote sound flood plain management. In some states or communities 1 flood manaqement criteria or requlations may exist that are more restrictive or comprehensive than those on which these federally-supported studies are basedc These criteria take precedence over the minimum federal criteria for purposes of requlating in t.he flood plain, as set forth in the Code of Federal ons at 44 CFR, 60~3~ In such cases, ho\o1ever, it shall be unc.h_';rstood that the state (or other jurisdictional agency) shall be able to n t_hese requirements and criteria~ 1 ~ 2 huthor.ity and Acknowledgements The source of for this Flood Insurance Study is the National Flood Insurance Act of 1968 and the Flood Disaster Protection Act of 1973. The c and hydraull c analyses for this study were prepared by DeleuvJ, Cather and Company of New York f Inc*, for Federal Insurance Administ:rat_ion, under Contract No. H-4552. This work was in November '1979~ ~3 Coordination Iden"cification s·treams to be studied detailed and approximat:e mt:tJ1ods was made at t.:he initial Consul tat.ion and Coordination Officer's (CCO} mec'-'t:Lnq on t'1ay 23t 1977 r between the F'I/\ 1 DeLeuw, Cather a'1d Company of Nevi York£ Inc", {the study contractor), and tohn officials. For tl-1ose :c;treams stuciied in detail, techni ca 1 data were coordinat~ed with the NevJ York St~a-te Department of Environmental conservation (NYSDEC), the U. S. GeoJ Survey (USGS}, the U0 S~ Army Corps of Engineers (CO£), the Erie~l'--Eagara Counties Reg:Lona} Board and the ing fj_ rms of Erdman, AntJ:ony Associates and Goodkind O'De-a. OthPr orqanizut_ions contacted for information .included t.he Soil Conservation Scrv.:i ce ( SCS) 1 t;he New York State Depart.rr.ents of Hiyhv;a_y Planrd ng, Dra:i naqP and Scmitation, Environment.al Quality and Sol 1 s Conservation. Information from the general public was solicited thrcuqh newspaper announcements in October 1977~ on September 3, 1980, results of this s·tudy were reviewed at a final c-,.-­ meeting attended by representatives of the FIA, the study contractor and the Town. of Tonawanda~ 2.0 ARE/\ STUDIED 2~1 Scope of Study This Flood Insurance Stud.y covers the incorporated area of the Tovm of Tonawanda, Erie County, New York. 'l'he area of study is shO'i"''TI on the Vicinity Map (Figure 1). li. 2, 500-foot portion of Ellicot·t Creek, centered around Colvin Boulevard, was studied by detailed methods. The Niagara River-Tonawanda Channel was studied in detail from about: 2, 000 feet upstream of Motor Island to the upstream corporate limits of the Town of Tonawanda~ Tonawanda Creek was studied from the northeastern corporate limits to a point about 1,600 feet upstream. The areas studied by detailed methods were selected with priority given to all known flood hazard areas and areas of projected development and proposed construction for the next five years, through November 1984. A portion of Ellicott Creek from Niagara Falls Boulevard to 1,000 feet upstrefutt of Colvin Boulvard, and the portion of the Niagara River­ Tonawanda Channel between a point about 2,000 feet upstream of Motor Island tn the upstream corporate limits were studied by approximate methods. A portion of Tonawanda Creek was also studied by approximate methods~ methods of v;ere used to study t"bose areas hav low development al and minimal flood hazards as identified at the: initiation of the study~ The scope and methods of study were to and aqreed upon the FIA ~ 2~2 Comnmnity Thf:: Town of TcmaHanda is located .in western New York State in the nortJn-vest corner of Erie County and, with the Village of Kenmctre, forms the northern of the of Buffalo. Thf' -r.ov.m is bordered by the: City of North 'Tonawanda to the north, the Town of Amherst to the east t t.he City of Buffalo to the south, and by the City of Tonawanda and the Niagara River-Tonawanda Channel to the west- 2 I I I ~-r I 'fiI ~ ! I ! I ! I I The Town of Tonawanda was formed from the City of Buffalo on 1\pril 16 1 1836~ It has an area of 19~8 square miles and in 1970 had a population of 107,282. The town is a mix of residential, commercial and industrial land, with some open space areas. Ellicott Creek Park, a county recreational facility 1 .is located vii thin the corporate limits, as are several town parks and golf courses. Ellicott Creek comprises the major drainage feature in Tonawandao Flowing west through the northern part of town, it joins Tona1danda Creek in the City of Tonawanda, meandering through Ellicott Creek Park. For part of this reach, development along the banks is residential and commercial .. Surface soils \Vi thin the town reflect the texture of the glacial t.J ll and lake deposts from which they are formed. 'rhe predominant surface soi_ls are unsorted rock material, forming a thin mantle over the bedrock in tlv~ southern portion of town 1 and interbedded clay, silt and fine sand in the remainder of town. Soils are generally shallow and well-drained. Elevations within the community vary from 570 feet to 620 feet. Precipitation in the study area averages 33.0 inches annually. The average annual snowfall is 85~0 inches. Average temperatures range from 42 degrees Fahrenheit { °F) to 86°F in summer and from -7°F to 30°F in the winter. 2.3 Principal Flood Problems The low-lying areas of Tonawanda have been subject to frequent and great depths of flooding~ Floods usually occur in the late winter or early spring and are caused by melting snow coincident with moderate amounts of rainfall~ Flood hazards have been lessened since the construction of a diversion channel from Ellicott Creek to Tonawanda Creek. It was constructed in the summer of 1965 and is located upstream of Niagara Falls Boulevard.. Only minor damages have been sustained within Ellicott Creek Park. 'l'he most recent flood occurred in .0-1arch 1960, inundating parts of the town~ Other arge floods occured in March 1916, January 1929, l>'la:r.-ch 1936, June 1937, March 1940, l'Jiarch 1954 1 Ivlarch 1956, January 1959 and March 1963~ The maximum recorded flood of march 1960 had a discharge determined to be a 20-year event at a location 11 miles upstream of Tonawanda. The greatest knm.,zn flood occurred on march 17, 1936, and was estimated to be a 50-year event~ 4 A damage survey of the area flooded by the March 1960 flood was made in the summer of 1962 by the Buffalo District of the COE.. Only minor damages were sustained within the Town of Tonawanda. Figures 2 and 3 illustrate potential flood elevations within Tonawanda. Figure 2 - The potential 1 00-year flood \vould be approximately 3 feet lower than the bottom of the Colvin Boulevard bridge over Ellicott Creek. Figure 3 is approximately 0 .. 5 foot lower than the 9round floor of the bui_ at the Her Road School. 2. 4 Flood Protection Measures Con;.:;truction of a divnrsion r:hanne-l Jn Ellicott Crc,ek P:1rk from E]i;r:iltt Cr0('k to Tonawanda Creek, in \:hP i.own, Wd~; (:<nnpJ,-ted in 1<)(/;. '!'hi.<: channel has lesseneri tfw flood hdzard;:_; from Ellicot_t cr-('C:k within Tonawanda. Major channelization and diversion channels for Ellicott Creek in the Town of Amherst and widening of the diverionary channel in Ellicott Creek Park between Ellicott Creek and Tonawanda Creek in tl-1e Town of Tonawanda are planned and funded for construction.