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Author: United States. Army. Corps of Engineers. Vicksburg District
Publisher:
Published: 1978
Total Pages: 160
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DOWNLOAD EBOOK →Author: Steve Brady
Publisher:
Published: 1979
Total Pages: 51
ISBN-13:
DOWNLOAD EBOOK →Lake Torino Dam is an earthfill structure approximately 38.5 ft high and 570 ft long at the crest. The appurtenant works consist of a 10-in. diameter steel pipe primary spillway located near the center of the dam and a grass-covered earth emergency spillway located at the north end of the dam. Our inspection and evaluation indicates that the combined spillways do meet the criteria set forth in the guidelines for a dam having the above size and hazard potential. The combined spillways will pass 57 percent of the Probable Maximum Flood without overtopping. Deficiencies visually observed by the inspection team were: (1) erosion at the contacts of the dam with the north and south abutments; (2) tree and brush growth along upstream and downstream faces of dam; (3) animal burrows along upstream and downstream faces; (4) a few small sloughs on upstream face; (5) seepage areas on downstream face and wet areas at toe of dam; (6) debris and brush around intake to primary spillway; (7) outlet channel of primary spillway overgrown with trees and brush; and (8) swale at south end of dam.
Author:
Publisher:
Published: 1980
Total Pages: 66
ISBN-13:
DOWNLOAD EBOOK →The purpose of this inspection was to make an assessment of the general condition of the dam with respect to safety, based upon available data and visual inspection, in order to determine if the dam poses hazards to human life or property. The inspection and evaluation indicates that the combined spillways do not meet the criteria set forth in the guidelines for a dam having the above size and hazard potential. The combined spillways will pass 25 percent of the Probable Maximum Flood without overtopping. The Probable Maximum Flood is defined as the flood discharge that may be expected from the most severe combination of critical meteorologic and hydrologic conditions that are reasonably possible in the region. The guidelines require that a dam of small size with a high downstream hazard potential pass 50 to 100 percent of the PMF. Considering the low height of dam (26 ft) and the small storage capacity (64 acre-ft) 50 percent of the PMF has been determined to be the appropriate spillway design flood. The embankment was in good condition.
Author: Henry M. Reitz
Publisher:
Published: 1978
Total Pages: 52
ISBN-13:
DOWNLOAD EBOOK →The purpose of the inspection was to make an assessment of the general condition of the dam with respect to safety, based upon available data and visual inspection to determine if the dam poses hazards to human life or property. The inspection and evaluation indicates that the dam is deficient in that the spillways do not meet the criteria set forth in the guidelines for a dam having the above size and hazard potential. Considering the volume of water impounded, the floodplain downstream and potential residential development downstream, the Probable Maximum Flood (PMF) is the appropriate spillway design flood. The probable maximum flood is defined as the flood discharge that may be expected from the most severe combination of critical meteorological and hydrologic conditions reasonably possible in the region. The dam will begin to be overtopped by a flood having a discharge (peak and volume) equal to 50% of the PMF. The spillways will pass 1% chance flood (100-year flood) without overtopping, which is a flood that has a 1% chance of being equalled or exceeded in any given year. There were indications of seepage or underseepage through or under the dam embankment. This is a serious safety deficiency which could lead to failure of the embankment.
Author: ARMY ENGINEER DISTRICT ST LOUIS MO.
Publisher:
Published: 1978
Total Pages: 43
ISBN-13:
DOWNLOAD EBOOK →This report assesses the general condition of the dam with respect to safety, based on available data and on visual inspection, to determine if the dam poses hazards to human life or property. Evaluation of the spillways' size indicates that they do not meet the criteria in the guidelines. The spillways of dams No. 2 and 3 are of inadequate size to pass the one percent chance flood (100-year flood) without overtopping. The spillway of dam No. 1 is just adequate to pass the one percent chance flood; but if either dam No. 2 or No. 3 failed due to overtopping, dam No. 1 would overtop also. The inspection team observed trees and bushes growing in the three dams inspected, particularly dam No. 3. These root systems are a potential seepage hazard. Localized areas of the embankment slopes are exceptionally steep. Steady seepage conditions exist through dam No. 1 and a localized seepage area was found downstream of dam No. 2. The pool of the dam No. 2 was on the downstream slope of dam No. 3 and seepage could not be evaluated. The three spillways do not appear sufficiently resistant to prevent embankment erosion at high flows for an indefinite time. Stilling basins are needed below each spillway. Seepage and stability analyses are not on record as recommended in the guidelines.
Author: Nathan Wilcoxon
Publisher:
Published: 1981
Total Pages: 64
ISBN-13:
DOWNLOAD EBOOK →Spring Lake Dam is an earthfill structure approximately 21 feet high and 400 feet long at the crest. The appurtenant works consist of a drop-inlet pipe principal spillway and a trapezoidal channel cut into natural ground at the left abutment which acts as an emergency spillway. Our inspection and evaluation indicates that the spillway has not met the criteria set forth in the guidelines for a small size dam in the high hazard potential category. This structure has the capability to hold and pass approximately 40 percent of the Probable Maximum Flood (PMF) before overtopping. The dam appeared to be in fair condition. Deficiencies visually observed by the inspection team were: (1) a row of trees (approximately 8) along the upstream face of the dam; (2) a significant potential for restriction to flow into the principal spillway intake; (3) some minor erosion on the downstream face of the dam; (4) the emergency spillway channel is partially obstructed by six steel drums and a fence; and (5) minor seepage into the principal spillway conduit from within the embankment.
Author: ARMY ENGINEER DISTRICT ST LOUIS MO.
Publisher:
Published: 1978
Total Pages: 36
ISBN-13:
DOWNLOAD EBOOK →This dam is classified as a small size dam with a high downstream hazard potential. Failure would threaten the life and property of approximately 5 families downstream of the dam. The spillway does not meet the criteria set forth in the guidelines for a dam having the above mentioned size classification and hazard potential. According to the guidelines, the spillway is required to pass the Probable Maximum Flood (PMF) without the dam embankment being overtopped. The spillway will only pass 5 percent of the PMF before the dam embankment is overtopped. Because the spillway will not pass one-half of the PMF without overtopping, the dam is classified as 'unsafe Non-emergency'. The spillway will not pass the 100-year flood without overtopping, which is a flood that has a 1 percent chance of being exceeded in any given year. Other deficiencies visually observed by the inspection team were trees and bushes next to the concrete core wall, in and adjacent to the principal spillway, and on the downstream embankment slope; erosion gullies on the downstream embankment slope; and seepage. Another deficiency found was the lack of seepage and stability analysis records.
Author: ANDERSON ENGINEERING INC SPRINGFIELD MO.
Publisher:
Published: 1980
Total Pages: 66
ISBN-13:
DOWNLOAD EBOOK →Our inspection and evaluation indicates that the combined spillways do not meet the criteria set forth in the guidelines for a dam having the above size and hazard potential. The combined spillways will pass 30 percent of the Probable Maximum Flood without overtopping. The Probable Maximum Flood is defined as the flood discharge that may be expected from the most severe combination of critical meteorologic and hydrologic conditions that are reasonably possible in the region. The guidelines require that a dam of small size with a high downstream hazard potential pass 50 to 100 percent of the PMF. Considering the low height of the dam and the small storage capacity, 50 percent of the PMF has been determined to be the appropriate spillway design flood. The 1 percent probability flood will not overtop the dam. The 1 percent probability flood is one that has a 1 percent chance of being exceeded in any given year. Deficiencies visually observed by the inspection team were: scattered trees and brush on both the upstream and downstream face; lack of wave protection for the upstream embankment face; minor erosion at the left downstream dam-abutment contact; minor slough above the outlet of the drawdown pipe; and possible seepage area beyond the downstream toe on the left side of the valley. Another deficiency was the lack of seepage and stability analysis records.
Author: Walter G. Shifrin
Publisher:
Published: 1980
Total Pages: 124
ISBN-13:
DOWNLOAD EBOOK →Trojan Lake Dam is situated within the state of Missouri, in the county of Lincoln, across Buchanan Creek which is tributary to the Cuivre River. The purpose of the dam is to impound water for recreational use as a private lake. The lake is utilized by landowners of Trojan Lake Estates subdivision development. The dam crest supports a small dirt road with a vegetative cover lying on both sides. Damage due to vehicular traffic was observed in a few areas. Several deep ruts were observed and in one area, the damage extended down the upstream slope. The vegetative cover was fairly sparse and did not appear to be sufficient protection against erosion. There was no evidence of significant settlement or cracking on the crest. Small shrinkage cracks were observed. No significant deviations in horizontal or vertical alignment were apparent. There was no evidence observed indicating that the dam has ever been overtopped.
Author: Leonard M. Krazynski
Publisher:
Published: 1980
Total Pages: 54
ISBN-13:
DOWNLOAD EBOOK →Potosi Lake Dam is an earth dam constructed for recreational purposes. The main spillway is a 3-ft dia corrugated metal pipe (CMP), or culvert, which discharges into an unlined earth channel. A 2-ft dia CMP serves as the auxiliary spillway and discharges into the same channel. A siphon (12-in. dia steel pipe) crosses the dam at about the midpoint. It crosses under the road and rests on the downstream slope. It discharges at the dam toe. The inspection and evaluation indicate that the dam is in generally poor condition. Specific deficiencies that were noted are inadequate spillway capacity, the high potential for spillway blockage, the dense growth of large trees and brush on the downstream slope and along the upstream crest, and lack of maintenance and periodic inspections. Hydrologic/Hydraulic studies indicate that the 10 percent probability-of-occurrence event (10-yr flood) will cause overtopping of the dam. These analyses also indicate that the dam will be overtopped for a hydrologic event which produces greater than eight percent of the Probable Maximum Flood.
