National Dam Safety Program. Stergen Lake Dam, No Name 448 (MO 30606), Missouri - Kansas City Basin, St. Charles County, Missouri. Phase I Inspection Report PDF Download

Author: Henry M. Reitz
Publisher:
ISBN:
Category :
Languages : en
Pages : 47

View

Book Description
The dam is an earth structure built in the hilly ground at the west edge of the floodplain of Femme Osage Creek. Normal rainfall, runoff, transpiration, evaporation and seepage either through the dam abutments or the rock in the reservoir all combine to maintain a relatively stable water surface elevation. Our inspection and evaluation indicates the dam is deficient in that it has no spillway. The guidelines for a dam having the above size and hazard potential require that the spillway be capable of passing a Probable Maximum Flood (PMF). A PMF will overtop the dam to a maximum depth of 1.9 feet with a maximum flow of about 600 cubic feet per second. The dam is also deficient in that extensive and serious seepage through and under the dam embankment is occurring and there is erosion and possible sloughing on the downstream slope.

Author: Henry M. Reitz
Publisher:
ISBN:
Category :
Languages : en
Pages : 57

View

Book Description
No-Name 447 dam was inspected by an interdisciplinary eam of engineers. 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, in order to determine if the dam poses hazards to human life or property. Failure would threaten the life and property of ten families and cause appreciable damage to one county road. Our 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 and which require that the spillway be capable of passing a one-half PMF (Probable Maximum 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 that are reasonably possible in the region. The dam will begin to be overtopped by a flood having a discharge (peak and volume) equal to 25% of the PMF. The spillways will pass a 1% chance flood (100-year flood) without overtopping, which is a flood that has a 1% chance of being exceeded in any given year.

Author: Henry M. Reitz
Publisher:
ISBN:
Category :
Languages : en
Pages : 52

View

Book Description
No-Name 207 dam was inspected. 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, in order to determine if the dam poses hazards to human life or property. Our 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 and which require that the spillway be capable of passing a one-half PMF (Probable Maximum 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 that are reasonably possible in the region. The dam will begin to be overtopped by a flood having a discharge (peak and volume) equal to 20% of the PMF. The spillways will pass a 1% chance flood (100-year flood) without overtopping, which is a flood that has a 1% chance of being exceeded in any given year.

Author: Ralph E. Sauthoff
Publisher:
ISBN:
Category :
Languages : en
Pages : 62

View

Book Description
Based on the visual inspection and the results of the hydrologic/hydraulic investigations, the present general condition of the dam is considered to be somewhat less than satisfactory. Deficiencies were noticed during the inspection and are considered to have an adverse effect on the overall safety and future operation of the dam. Evidence of seepage, soft and wet ground near the toe of the center of the dam; soft ground and flowing water at the intersection of the toe of the dam and the right abutment; and running and standing water and cattails downstream of the toe of the dam was observed. The right bank of the outlet channel for the emergency spillway at a point adjacent to the dam was eroded to an extent that spillway releases within the capacity of the outlet would not be confined to the channel. Damage by unconfined spillway releases to the dam and to other areas downstream of the dam can occur during periods when lake outflow passes the emergency spillway. Erosion of the grass covered upstream face of the dam apparently by wave action and/or by fluctuations of the lake surface level has created a near vertical bank approximately 6-to-12 inches high at the normal waterline.

Author: Paul R. Zaman
Publisher:
ISBN:
Category :
Languages : en
Pages : 42

View

Book Description
Crystal Lake Dam was inspected by a team of engineers. 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, in order to determine if the dam poses hazards to human life or property. Our inspection and evaluation indicates the spillway does meet the criteria set forth in the guidelines for a dam having the above size and hazard potential. The spillway will pass the probable maximum flood without overtopping. It should be noted that a flood of this magnitude would inundate major portions of Excelsior Springs, Missouri as indicated in the Flood Insurance Study for Excelsior Springs, Missouri, U.S. Department of Housing and Urban Development, Federal Insurance Administration.

Author: Walter G. Shifrin
Publisher:
ISBN:
Category :
Languages : en
Pages : 82

View

Book Description
Branneky Lake Dam was inspected. The inspection and evaluation of the consultant's inspection team indicate that the spillway of Branneky Lake Dam does not meet the criteria set forth in the guidelines for a dam having the above size and hazard potential. Branneky Lake Dam being a small size dam with a high hazard potential is required by the guidelines to pass from one-half of the Probable Maximum Flood to the Probable Maximum Flood without overtopping the dam. Considering the small drainage area, the small storage capacity of the reservoir, the height of the dam, and the small number of dwellings in the downstream hazard zone, one-half of the Probable Maximum Flood is considered the appropriate spillway design flood for Branneky Lake Dam. 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 that are reasonably possible in the region. It was determined that the reservoir can store approximately 5 percent of the Probable Maximum Flood without overtopping the dam. The evaluation also indicates that the reservoir cannot accommodate the ten-percent chance flood without overtopping the dam.

Author: Walter G. Shifrin
Publisher:
ISBN:
Category :
Languages : en
Pages : 84

View

Book Description
This report was prepared under the National Program of Inspection of Non-Federal Dams. 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. (Author).

Author: Henry M. Reitz
Publisher:
ISBN:
Category :
Languages : en
Pages : 56

View

Book Description
The dam is an earth structure built in a narrow draw in the uplands of the Missouri River Bluffs. An 8-inch steel pipe (principal spillway) is provided to drain off excess water from the lake. Additional spillways (emergency spillways), flat channels excavated in earth, are provided at each abutment. Our inspection and evaluation indicates that the spillway does not meet the criteria set forth in the guideilnes for a dam having the above size and hazard potential. The dam will begin to be overtopped by a flood having a discharge (peak and volume) equal to 35% of the PMF. The dam storage and principal spillway will contain a 1% chance flood (100-year flood) without overtopping the emergency spillway. Other deficiencies observed by the inspection team were tree growth starting on the downstream face, and shallow erosion channels on the downstream face and at the toe of the dam on the west slope.

Author: Richard G. Berggreen
Publisher:
ISBN:
Category :
Languages : en
Pages : 59

View

Book Description
This dam has been classified as unsafe, non-emergency by the St Louis District as a result of the application of the following criteria: (a) Spillway will not pass 50 percent of the Probable Maximum Flood without overtopping the dam; (b) Overtopping of the dam could result in failure of the dam; and (c) Dam failure significantly increases the hazard to loss of life downstream.

Author: Henry M. Reitz
Publisher:
ISBN:
Category :
Languages : en
Pages : 55

View

Book Description
The dam is an earth structure built in the uplands of Sehrt Creek, 2-1/2 miles from the edge of the Missouri River Valley. There is no principal spillway. There are two emergency spillways. At the east end is an emergency spillway about 180 feet long on a flat grade in virgin soil approximately 50 feet wide and 3 feet deep. At the west end is a smaller capacity spillway which is a dip in a road with low point more than 2 feet higher. Our inspection and evaluation indicates the dam is deficient in that the spillways are inadequate. The guidelines for a dam having the above size and hazard potential require that the spillway be capable of passing a one-half PMF (Probable Maximum Flood). A 25% PMF will begin to overtop the dam. The dam and spillways are adequate to contain the 100-year flood. Our inspection and evaluation indicate significant tree and underbrush growth on both faces of the dam which could lead to conditions causing rupture of the dam. Other deficiencies found are lack of erosion protection on the upstream slope of the dam, no effective erosion protection on the spillways and lack of seepage and stability analyses records.