Download or read book National Program for Inspection of Non Federal Dams Amston Lake Dam CT 00544 Connecticut River Basin Hebron Connecticut Phase I Inspection Program written by CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV. and published by . This book was released on 1979 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: The dam is an earth embankment approximately 10 feet wide at the top and 400 feet long with the top approximately 10 feet above the streambed of an unnamed tributary to Raymond Brook. A central portion of the earth dam is comprised of a high area of natural ground to within a horizontal distance of 20 feet from the left spillway abutment. The spillway is a 15 foot long broad crested concrete weir of trapezoidal cross-section with vertical concrete training walls. The low level outlet is an approximately 1 foot square conduit through the spillway section. The flow through the conduit is regulated by a hand operated submerged gate mechanism adjacent to the upstream face of the spillway section. Based upon the visual inspection at the site and past performance, the dam is judged to be in poor condition. There was erosion evident on the upstream slope and crest of the dam, as well as numerous footpaths on the downstream slope. There were also significant amounts of seepage observed on the downstream slope and along the downstream toe of the dam. Other deficiencies include trees and brush on the dam embankment and a low beach area adjacent to the left end of the dam. Based upon hydraulics computations, the spillway capacity is 180 cfs which is equivalent to 113 percent of the routed Test Flood outflow. It should be noted that the above figures assume the low area at the left end of the dam to be raised to the top of the dam.

Download or read book Government Reports Annual Index written by and published by . This book was released on 1984 with total page 1316 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book National Program for Inspection of Non Federal Dams Silver Lake Dam CT 00254 Connecticut River Basin Berlin Connecticut Phase I Inspection Report written by CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV. and published by . This book was released on 1979 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 140 foot long dam is an earth embankment, the top of which, at elevation 154.5, is approximately 15 feet above the streambed of Belcher Brook. A drop inlet at a flow line elevation about 4.5 feet below the top of the dam, is the spillway facility. A wooden gate extending the full 7.5 foot depth of the structure is the low level outlet, however it is apparently stuck in a closed position. The inlet structure feeds an arched brick culvert which has an estimated chord length of 7 feet and an effective depth of approximately 3 feet, due to heavy siltation. A recent partial collapse of the brick culvert where it abuts the downstream low-level outlet headwall caused partial blockage of the culvert as well as an approximately six foot wide cavity and sloughing to the crest of the dam on the downstream slope. Based on the visual inspection at the site and past performance, the dam is judged to be in very poor condition. Evidence of instability was noted in the form of a collapse of the outlet conduit and a subsequent failure of the downstream slope of the dam. There are other areas requiring attention as well. Based upon the hydraulics computations, the spillway capacity is 180 cfs to the top of the dam, which is equivalent to 72% of the routed test flood outflow.

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1984-11 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book National Program for Inspection of Non Federal Dams Lake Wintergreen Dam CT 00118 Quinnipiac River Basin Hamden Connecticut Phase I Inspection Report written by CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV. and published by . This book was released on 1978 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt: The dam consists of two sections. The portion of the dam from the spillway 185 feet to the left is an earthen embankment on the upstream side of a rubble masonry retaining wall. The remaining portion of the dam to the left of the retaining wall is an earthen embankment. According to the existing information, a rubble masonry corewall exists from the spillway 260 feet to the left. The spillway is reported as a 50-foot-wide concrete weir flowing to a steep channel cut into natural rock formations. A 16 inch diameter high level intake approximately 900 + or - feet to the right of the dam was used as a supply main. The supply main is operable, however the reservoir is not used as a water supply due to the turbidity and poor color quality of the water. A 12 inch, low level inlet passes through the dam, but is presently inoperable. Based upon visual inspections at the site and past performance history, the dam is judged to be inf air condition. No evidence of structural instability in the retaining wall or the embankment portions of the dam was observed. However, the masonry retaining wall is very irregular making it impossible to detect any misalignment or movement of the wall. There are areas requiring attention. Based upon our hydraulic computations, the spillway capacity is 850 cubic feet per second, which is equivalent to approximately 28 percent of the Test Flood. Peak inflow to the reservoir is 3,500 cubic feet per second; peak outflow (Test Flood) is 3,000 cubic feet per second with the dam overtopped 0.8 feet.

Download or read book National Program for Inspection of Non Federal Dams Crystal Lake Dam CT 00138 Lower Connecticut River Basin Middletown Connecticut Phase I Inspection Report written by CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV. and published by . This book was released on 1980 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: Crystal lake is an earthen embankment dam with a maximum height of 50 feet and a length of 130 feet. The upstream and downstream slopes are faced with riprap. The dam has a water control structure with a 36-inch diameter outlet pipe controlled by two sluice gates and a stop log spillway. The dam impounds Crystal lake which is used for recreational purposes. The lake has a storage volume of 350 acre-feet. Based upon the height of the dam, the size classification is intermediate. The dam is judged to be in generally fair condition. The crest is level, and no lateral movement was observed. The vertical and horizontal alignment of the dam is good. Some minor erosion along the dam adjacent to the left abutment was noted. The riprap paving on the upstream face is in good condition. The rockfill downstream face is also in good condition. Small trees and scrub brush are growing on the upstream and downstream slopes and could cause problems if not removed. The total capacity of the water control structure and the 36-inch diameter outlet pipe is adequate to pass the spillway test flood with a freeboard of 0.8 feet.

Download or read book National Program for Inspection of Non Federal Dams Moulsons Pond Dam CT 00420 Connecticut River Basin Lyme Connecticut Phase I Inspection Report written by CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV. and published by . This book was released on 1981 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Moulsons Pond Dam is a stone masonry dam approximately 80 feet long and 23 feet high. The spillway is L shaped with a concrete cap that extends almost the total length of the dam. A bridge spans over the river immediately downstream of the spillway. The top of road is the dam crest and the west bridge abutment is the west spillway abutment. There is a 2-foot high concrete abutment at the east end that is 8 feet below the top of the dam. At the west end of the dam there is a 6-foot diameter pipe that passes beneath the roadway into a sluiceway that goes to an old mill. There is no control for this sluiceway which is always open and the water discharges into the downstream channel. There is no low-level discharge pipe.

Download or read book National Program for Inspection of Non Federal Dams Stub Pond Dam CT 00265 Connecticut River Basin Avon Connecticut Phase I Inspection Report written by CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV. and published by . This book was released on 1981 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dam consists of an earth embankment, and a concrete wall which extends from the embankments to the spillway on each end of the spillway. The earth embankment is 500 feet long, 8 feet wide at the top and 6.7 feet high, with a downstream slope of 2H:1V. The concrete spillway is located at the western end of the dam and is 40 feet long with 15 inch high permanently attached timber flashboards. Based on the visual inspection, and past operational performance, the dam is judged to be in POOR condition. There are large trees growing on the embankment. The concrete wall is severely cracked and spalled and has been exposed on the downstream side by erosion. Seepage is occurring through the wall and all along the downstream toe of the embankment. The test flood for this dam is the 100 year flood. The test flood has an inflow equal to 1810 cfs and an outflow discharge equal to 1800 cfs at a stillwater elevation of 233.1 which will overtop the dam by 1.0 foot. The maximum outflow capacity of the spillway with the water level at the top of the dam is 53 cfs, which is 3 percent of the test flood outflow.

Download or read book National Program for Inspection of Non Federal Dams Risley Reservoir Dam CT 00211 Connecticut River Basin Vernon Bolton Connecticut Phase I Inspection Report written by CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV. and published by . This book was released on 1978 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: The dam is located on a tributary of the Connecticut River on the town line of Bolton and Vernon, Tolland County, Connecticut. It is an earthfill structure approximately 625 ft. long with a maximum depth at its center of 26 ft. The crest width varies from 12 to 15 feet. A vertical granite masonry wall extends from the downstream side of the crest to the bed of Lydall Brook below. The visable part of the upstream embankment has a 1 on 2 to 1 on 3 slope with a riprap face. The downstream embankment consists of cobbles and boulders piled against the face of the masonry wall on an approximate 1 on 1.5 slope. The dam is in generally good condition. It appears to be structurally stable at the present time under normal conditions. Based on its small size and high hazard classification in accordance with the Corps' guidelines, the test flood is 1/2 the PMF. The spillway will pass only about 44 percent of the test flood and is considered inadequate. Recommendations to improve dam safety are: (1) Increase spillway capacity; (2) Replace 6-in. discharge pipe and relocate valve; (3) Add riprap near the center on the downstream side; (4) Divert spillway discharge away from the toe of the dam.

Download or read book National Program for Inspection of Non Federal Dams Lake Winnemaug Dam CT 00123 Naugatuck River Basin Watertown Connecticut Phase I Inspection Report written by CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV. and published by . This book was released on 1980 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lake Winnemaug Dam is an earth embankment approximately 500 feet long with a maximum height of about 15 feet. The upstream slope of the embankment is approximately 1H:1V and the downstream slope is about 1.5H:1V. The top of the dam is about 20 feet wide and it is a paved road. The overflow drop spillway is located about 100 feet from the right abutment and consists of an 18.5-foot long concrete weir, a cascading step section and a 4-foot high by 10-foot wide culvert through the embankment. The original purpose of the dam is unknown; however, the lake is currently used for recreation purposes. The peak test flood inflow for Lake Winnemaug Dam is 3,460 cfs. The routed test flood outflow of 2,010 cfs overtops the dam by about 0.8 feet. The spillway is capable of discharging 770 cfs or about 38 percent of the routed test flood outflow prior to overtopping of the dam. A breach of the dam would result in a 7.8-foot increase in the stream depth (3.8 feet above the channel banks) at the initial downstream damage area. The dam appears to be in poor condition. Numerous structural deficiencies, such as slope failures, seepage, and toe erosion were observed during the visual inspection. The embankment is overgrown with brush and trees and contains a number of rodent holes. The reservoir cannot be drained in an emergency because the outlet pipe control valve is inoperable.

Download or read book National Program for Inspection of Non Federal Dams Shenipsit Lake Dam CT 00209 Hockanum River Basin Vernon Connecticut Phase I Inspection Program written by CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV. and published by . This book was released on 1978 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Shenipsit Lake Dam is a granite stone masonry structure 70 feet long and 27 feet high. It has an emergency spillway, diversion conduit and an adjacent earth fill dike. Based on visual inspection, records available at the site and past operational performance, the dam is judged to be in fair condition. However, a review of the limited engineering data available reveals that there are areas of concern which must be corrected in order to assume the safety of the dam. The earth dike embankment as well as the masonry spillway have questionable structural capacity. The seepage of water into the Roosevelt Mills parking lot is of concern as a result, we feel this condition needs to be studied further. Based on selected size and hazard classifications, the Probable Maximum Flood (PMF) was selected to test the hydraulic adequacy of the spillway. It was determined that the spillway would pass only 16.5 percent of the peak discharge of such an event before overtopping of the dam would occur.

Download or read book National Program for Inspection of Non Federal Dams Crescent Lake Dam CT 00277 Connecticut River Basin Enfield Connecticut Phase I Inspection Report written by CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV. and published by . This book was released on 1978 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: Crescent Lake Dam is about 600 ft. long, 12 ft. high and has a crest width of about 15 ft. It is an earthen embankment with a downstream slope of about 2 to 1 and a variable upstream slope. There is no orthodox spillway structure, but an unlined channel in the reservoir bank near the right abutment serves as a wasteway for reservoir spills. An outlet canal takes off from the reservoir about 600 ft. upstream from the left abutment, which has a concrete headwall incorporating a 38 in. wide notch with stoplog slots. There appears to be no other outlet structure. Maximum storage capacity is about 335 acre-feet. Crescent Lake, used now for recreational purposes, is less than a mile long, has a surface of about 36 acres and a drainage area of about two square miles. The dam is in fair condition. There is some seepage along the downstream toe of the embankment, which has large mature trees growing on it. The lack of any outlet gate precludes drainage the lake without breaching the dam. The test flood would not overtop the dam but would reach within 1/2 ft. of the crest and overtop areas of reservoir bank adjacent to both left and right abutments, which appear to be as much as 2 ft. lower than the crest of the dam. It appears that the valley area east of the Penn Central Railroad track which is just downstream from the dam would absorb outflows up to the test flood magnitude without major consequences to downstream interests.

Download or read book National Program for Inspection of Non Federal Dams Highland Lake Dam CT 00106 Connecticut River Basin Winchester Connecticut Phase I Inspection Report written by CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV. and published by . This book was released on 1979 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: The dam is approximately 450 feet long on the paved roadway running along the axis of the dam which serves as a town street and is approximately 40 feet wide. With a maximum height of approximately 14 feet, the dam is composed of a downstream dry-laid stone masonry wall with an upstream earth fill. The upstream slopes are inclined gently into the lake and are protected by dumped riprap. The two spillways are actually lowered portions of the roadway. The spillways, each 75 feet long, discharge over the downstream masonry wall and onto a dumped riprap splash apron. The low level outlet is a culvert through the dam from 2 low level sluice gates located at the upstream face of the dam. From this outlet, water is routed either to a small generator in the Union Pin Company factory immediately downstream of the dam, or to a discharge channel alongside the factory and back into the stream. Based on the visual inspection at the site and past performance, the dam is judged to be in fair condition overall. No evidence of instability was observed in the dam or its appurtenances, and the condition of the earth dikes was good. Based upon the size (Intermediate) and hazard classification (High) of the dam in accordance with Corps of Engineers Guidelines, the test flood will be equivalent to the Probable Maximum Flood (PMF). Peak inflow to the lake is 9,500 cubic feet per second (cfs); peak outflow is 6,000 cfs with a freeboard of 1.0 feet to the top of the project. Based on our hydraulics calculations, the spillway capacity is 8,600 cfs, which is equivalent to 143% of the routed test flood outflow.

Download or read book National Program for Inspection of Non Federal Dams Mill Pond Dam CT 00164 Connecticut River Basin Newington Connecticut Phase I Inspection Report written by CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV. and published by . This book was released on 1981 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mill Pond Dam is an earth-covered, irregular natural rock formation 600 ft. long, with a top width varying from 10 to 20 ft. and a maximum height of 19 ft. The outlet for the dam is a natural rock weir spillway approximately 35 ft. wide, which is overpassed by a footbridge. The crest of the spillway is about 3 ft. below the lowest point on the dam crest. Based on visual inspection, the Mill Pond Dam is judged to be in good condition; however, during the inspection, there was a light snow cover of approximately 2 inches which may have obscured problems, such as erosion or seepage. A test flood of a 100 year frequency was selected in accordance with the Corps of Engineers' Guidelines. The calculated test flood inflow of 1,000 cfs results in a routed outflow of 990 cfs. With the water level at the top of the dam the spillway capacity is 575 cfs which is 58% of the outflow flood. The storage capacity of the Mill Pond is 52 ac.-ft. at the top of the dam.

Download or read book National Program for Inspection of Non Federal Dams Millen Lake Dam NH 00236 NHWRB Number 245 04 Connecticut River Basin Washington New Hampshire Phase I Inspection Report written by CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV. and published by . This book was released on 1980 with total page 103 pages. Available in PDF, EPUB and Kindle. Book excerpt: The dam is an earthfill gravity structure about 23 ft. high and 115 ft. long. The dam is considered to be in fair condition. It is intermediate in size with a significant hazard potential. There are various recommendations that should be implemented by the owner. (Author).

Download or read book National Program for Inspection of Non Federal Dams Upper Mill Pond Dam CT 00141 Connecticut River Basin Middletown Connecticut Phase I Inspection Report written by CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV. and published by . This book was released on 1981 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Upper Mill Pond Dam is a stone masonry dam approximately 100 feet long and 15 feet high. The spillway is 92 feet long, 9 feet wide and consists of a masonry broad crested weir. The water level is at the spillway crest and can be lowered by opening the low-level discharge gate which was recently made operable by the Middletown Water Department. In general, the overall condition of the dam is FAIR. The structural stability of the dam is good as evidenced by its vertical, horizontal and lateral alignment. The stone masonry is in good condition although moss and weeds are growing from the joints. The spillway weir and east abutment are in good condition. The west abutment is badly spalled at its base. The discharge gate inlet structure is badly spalled and the bar rack is cluttered with debris. There is some seepage at the east end of the dam where the stone masonry meets the abutment/ledge interface. Vegetation is growing around this area as well. The ledge continues along the downstream channel bank and there is minor seepage. A drainage pipe outlets above the west abutment. There is presently a scour hole at this location. This scour hole has caused the last section of the drainage pipe to collapse into the hole and is undermining the west spillway abutment. At the spillway elevation, the water surface area and storage capacity is 5 acres and 31 acre-feet respectively. The spillway capacity when the water level in the pond is at the top of the dam is 250 cfs. The test flood will overtop the dam by 1.8 feet.

Download or read book National Program for Inspection of Non Federal Dams Eastman Lake Dam HN 00039 NHWRB 97 04 Connecticut River Basin Grantham New Hampshire Phase I Inspection Report written by CORPS OF ENGINEERS WALTHAM MA NEW ENGLAND DIV. and published by . This book was released on 1979 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt: The dam has a maximum height of 45 ft. and is about 415 ft. long. The dam is judged to be in good condition. Two wet patches were observed on the downstream side above the elevation of the permanent pool. The dam is classified as intermediate in size with a hazard potential of high. There is work which must be done on the remaining spillway to assure the continued performance of the dam. (Author).