The Waterbury Democrat., 1941-09-09
FLOOD CONTROL
 DAM TO BE BUILT

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 ticut Flood damage, river levels and other data were gathered and ana lyzed. Nine serious floods since 1869 are described, details being given on the flood of November 1927, the flood of March, 1886, and the hurri- cane flash" flood of September, 1898. Damage in the. area studied from the 1888 flood was estimated at $2,S09,000.
 The report describes the proposed Thomaston dam as follows
 The Thomaston dam site Is lo- cated on the Naugatuck River, II miles north of ThomaSton Conn. The dam will be constructed of roll- ed earth and rock All to Q maximum height of i36 feet, with c side.chan- mel spillway, having a crest 406O feet above mean sea level and 200 feet, located in rock on the right bank. The dam will be of sufiicient height to accommodate Q maximum surcharfge of i5 feet, with an ad. ditional 5 feet of freeboard. The spillway channel will return to the present channel of the Naugatuck River 325 feet below the toe of the dam. The outlet conduit will be a tunnel of horseshoe section 700 feet long and i5 feet in diameter, lo- cated in rock in the right bank and controlled by three Broome-type gates, each 6 feet by l2 feet. The operating tower will be near the right abutment Access to the tower will be provided by service bridge. The reservoir will have a capacity of 4i 500 acre-feet, equivalent to 8 Inches of run-oH from the drainage area of 97 square miles. With the proposed Thomaston Reservoir filled to spillway crest, an area of ei0 acres in the towns of Harwinton, Plymouth, LitchAeld, and Thomas ton, in Litchfleld County, will be oc. cupied. Most of this land Is either suhmRginal or devoted to agricul- tural uses. Some of the storage cap- acity is located in tho valley of Leadmine Brook. The Waterbury and Winsted Branch of the New York, New Haven and Hartford Railroad is below Splllway crest ele- vation for Q length of 6.4 miles, making 1t necessary to relocate 90 miles of single track line. State Highway lto. Q, le feet wide, will require relocation for c distance of 6A miles. The total cost of the dam and reservoir will be &S,iSi 900, with annual charges of S260, 800. The total average annual benefits will accrue to this reservoir, computed as first ip the flood control system, are $se2000. The ratio of average an. nual benefits to annual costs is i.l2. This reservoir will provide high de- gree of protection for the entire Naugatuck River below the dam site.
 Waterbury's relation to the dam at Thomaston Is described as fol. lows:
 47. Waterbury Conn. = The di- rect flood losses for the September 1888 flood amounted to $e6,l00 in the town of Waterbury. The reach of the Naugatuck River from the South Leonard street Bridge to above the West Main street Bridge was studied in detail, and . survey record map of the entire reach was made. The September 1888 direct losses in this reach amounted to $40, 200. The Thonaston Reservoir would eliminate most of these losses in the future. Since that reservoir, with 6 fiood-control capacity of 6 inches, was found to be justified, only that section of Waterbury be- tween the Mad River and l,600 feet above Bank street was given fur. ther study. A channel improvement was investigated for this section, in which the dam of the American Brass Company would be removed and the channel would be excavated to uniform grade and cross sec- ton from the Mad River to the spur track railroad bridge of the Amer ican Brass Company, and from the Bank street Bridge to point 1900 feet upstream from the Bank street Bridge. With Thomaston Reservoir built to a capacity of 8 inches. the average annual cost of this local im- provement would greatly exceed the average annual benefit. Further studies proved that 1t would not be advantageous to build the Thomas ton Reservoir with a smaller capa- city than inches in combination with this channel improvement. With the Thomaston Reservoir built, no project can be justified in this short reach, where the flood damage is highly concentrated and the cost of the improvement moder- ate, The Thomaston Reservoir would likewise afford the most economi- cal protection for the remaining sec- ton of this highly induStrialized valley.