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indirect annual damage of $11,200 to urban development and $65,800 to industrial development, or a total annual damage of $77,000 within the Rosiclare flood damage area. These estimates were made by the use of elevation-damage curves and an elevation-frequency curve for the Ohio River. Supporting information, data, and computations are given in the appendix.'

40. During the 1937 flood two lives were reported lost. During a major flood, the public water-supply system ceases to function, and there is no electricity. The general health of the community is endangered. However, there is no record of any epidemic as a direct result of past floods. Local medical men and State health organizations are alert to such danger and in the past have employed preventative measures to forestall epidemics.

41. The elimination of floods would effect some increase in the property values given in paragraph 37. It is believed that a reasonable estimate of this enhancement would be about 15 percent of the present fair market value of improvements.

42. Eristing flood-control projects.—No flood-control projects for which the War Department is responsible have been constructed, or authorized by Congress for construction, at or in the vicinity of Rosiclare, Ill.

43. Improvements by other Federal and non-Federal agencies.- There have been no improvements by other agencies for flood control or any other water use in the locality under consideration.

44. Improvement desired.- A public hearing was held at Rosiclare, m., on November 20, 1945, by the district engineer, Louisville, Ky., for the purpose of securing the views and desires of local interests concerning flood-control measures which could be adopted for the protection of Rosiclare and vicinity. The hearing was open to the public and was attended by about 100 persons, nearly all of whom were from this locality. Among those present were a United States Congressman; & State representative; representatives from various State agencies, fraternal and civic organizations, and the fluorspar-mining companies; city officials, businessmen, and property owners.

45. The improvement desired is a flood wall or levee. A prominent citizen stated that a plan of protection was desired which would consist principally of a concrete flood wall constructed on rock foundation close to the water's edge of the Ohio River and enclosing the town and the mining properties. This plan contemplated a backfill behind the wall which would reclaim certain small areas which were eroded from the river bank during past floods. Several of the persons and representatives of organizations present requested the construction of a flood wall, and it is believed that the above is the plan to which considerable reference was made. City officials stated that the construction of a levee was desired. Many other persons reported that some form of protection should be provided. In justification for a plan of flood protection local interests asserted that past flood losses in this locality were sufficiently high to make such a plan feasible.

46. It was stated by prominent citizens that the community would be willing to fulfill the conditions of local cooperation for flood-control projects prescribed by present laws. At the present time it is doubtful if the community has sufficient resources to cover the cost of such cooperation. However, it is believed that local interests will take

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necessary steps toward furnishing satisfactory assurances of local cooperation to the Secretary of War in accordance with requirements of existing law. At the hearing, the State representative for the legislative district indicated that there was a possibility that the State would assist the community in providing funds for rights-of-way.

47. Surveys.-Geologic, soils, and engineer reconnaissance were made at and in the vicinity of Rosiclare. A plane table survey (scale, 1 inch equals 50 feet) was made for an average width of 300 feet along the proposed alinement of the protection works. A profile and crosssections were also taken along this alinement. A stadia topographic survey (contour interval, 2 feet) was made of the lower portion of Willow Creek for area-capacity information. Borrow areas were cross sectioned by use of stadia. To determine underground conditions, 13 auger holes were drilled on or near the structure centerlines to depths of from 7 to 20 feet. Six auger holes were drilled to a depth of 10 feet in borrow areas.

48. There are submitted with the main section of this report a map showing the general plan (enclosure 1) and maps showing the plan, profile and sections for the works (enclosure 2). There is included in the appendix as plate 1,' a general plan of the alternate plan of improvement studied.

49. Flood problem.--All possible methods of flood control were considered. Diversion of flood waters, channel improvement, reservoirs and removal of existing installations to higher ground are either impracticable or too costly to serve as a solution of the flood problem in this locality. Some form of levee or flood wall would be the only practicable solution. The plan suggested by local interests involving à concrete flood wall located near the water's edge along the town would be too costly due to the greater height of structure required. Further, separate protection for the mining properties was given consideration. However, the location of the mine shafts and mills together with the topography of the area point to a line of protection well removed from the mine properties. The plans selected for survey and investigation are an all-levee plan and a combined levee and flood-wall plan each composed of two sections, one of which would be located close to the river bank in the town, would cross Willow Creek and tie to the hills downstream therefrom. The other section would be located on the low divide between the two hills and high ground about 1 mile downstream from the town. Both the levee and the combined levee and flood-wall plans are described in the following paragraphs.

50. Plans of improvement.-General. Two plans of flood-control improvement were investigated. The selected plan involves the construction of two sections of earth levee together with a pumping plant for removal of sewage and accumulated interior run-off. The second plan involves construction of a concrete flood wall through the built-up area of the town and earth levee in the other locations. The location and general features of the selected plan are shown on map entitled, "General plan," enclosure 1, and details of the project are shown on maps entitled, “Plan, profile, and sections," enclosure 2. The general features and location for the alternate plan are shown on map entitled, “Alternate plan" (pl. 1, appendix).'

51. Design bases.-The criterion used to establish the grade line for the top of the earth levee and flood wall is that such a grade line

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will be 3 feet above the flow line of the 1937 flood, as modified by any existing or proposed works in the flood plain. This criterion has been used in the design and construction of other local protection projects along this reach of the Ohio River. Since the 1937 flood, no changes have occurred in the vicinity of Rosiclare which would tend to raise the natural flow line of the flood. Further, flow-line computations made with the contemplated improvements in place indicated that these would have no effect on raising the 1937 flood profile. The computed flow line indicated insufficient local slope to justify a variation in grade line. Accordingly, the grade of the levee and flood wall was established at elevation 367.5 feet (mean sea level) for the locality. The earth levee has 1 on 3 side slopes and a 12-foot crown. The flood wall is cantilever in type and its design is based on standards used for similar projects constructed by the War Department in this reach of the Ohio River.

52. The location chosen for the protection line affords reasonable safety for the structures. The river section (sec. 1) is alined behind a rounded point in the bluffs near the upstream end. The toe of the levee is 80 to 130 feet from the high bank and 240 to 300 feet from the edge of normal water surface. During past floods (prior to 1937 flood) the upper portion of the high bank sloughed off producing a foreshore averaging about 175 feet in width. There is no evidence indicative of active bank erosion at the location.

53. The back levee (sect. 2) crosses the Fairview-Rosiclare fault line. This fault has been worked for fluorspar for many years. The back levee is located above a plug left in the workings which separates old abandoned workings riverward of the levee from active workings to the landward. The maximum width of the workings near the levee site is about 10 feet, the depth of alluvial overburden is 60 to 80 feet and the thickness of the roof has not been determined. The faulting in this region is of the tension type and movement along the fault is considered a remote possibility.

54. At the present time the city of Rosiclare has no sanitary sewage system. However, construction plans have been made for a sewage system and a disposal plant, the construction of which is being withheld pending the initiation of a flood-protection project. deemed advisable to make provision in present flood-control plans for the construction of a sewage-pumping plant to lift sewage across the protection works during high stages of the Ohio River. The pumping capacity provided is the computed discharge of the outfall sewers in the proposed sewerage system.

55. Provision has also been made for a small pumping capacity to remove accumulations of interior run-off during high stages on the Ohio River. In addition to natural run-off there would also be accumulated behind the levee, a certain amount of water pumped from the mines into Willow Creek. Pumping capacity, now available at the mines, is considered to be committed to mine pumping and to be not available for any other purpose. The pumping capacity for handling natural run-off is such that run-off expected to be equaled or exceeded once in 10 years coincidental with a river stage at the selected minimum ponding elevation, will be removed without causing damage. This criterion is in current use at other locations in the Ohio Valley. The additional capacity required to handle mine pumping cannot be accurately determined but is based on the statement of a mine official

It was

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that normal pumping load is about 3,000 gallons per minute and that this increases about two-thirds during high river stages prior to flooding. There is a fairly large volume of natural storage available in and along Willow Creek. At elevation 343, which is zero damage elevation, the capacity available is about 230 acre-feet or 2.8 inches. At elevation 348 below which only a small amount of damage would occur, the storage available is 560 acre-feet or 6.7 inches. The volume of run-off accumulation which would have occurred during all past floods on the Ohio River from 1900 to date was investigated. Interior run-off accumulation without pumping would have exceeded elevation 343, or 2.8 inches of storage during only three of these floods, those of 1913, 1945, and 1937. The maximum accumulation would have been for the 1937 flood and would have reached approximately 12 inches causing considerable damage. With the pump capacity selected in accordance with the criteria mentioned above, no damage would have been caused by interior accumulation of run-off during the 1913 and 1945 floods and during the 1937 flood ponding elevation would have been reduced to approximately 348.5, or to an elevation where damage would have been comparatively low.

56. Description of selected plan.—Pertinent data for the selected plan of improvement are given in table 8. The embankment is rolled earth. The riverside slope of section 1 is protected by an 18-inch thickness of dumped riprap with a gravel blanket for protection against erosion, primarily wave wash. The landside of this section is seeded and both the landside and riverside of section 2 is seeded. Both sections have an exploration trench with an 8-foot bottom width and minimum depth of 6 feet. Section 2 has a continuous trench drain 15 feet inside the landside toe with 8-feet wide lateral drains extending to the toe and spaced a hundred feet part.

TABLE 8.-Pertinent descriptive data, selected plan of improvement,

Rosiclare, Ill.
Location:
River

Ohio.
Bank.

Right.
River miles below Pittsburgh, Pa.

891.4 to 892.5. Area protected

City of Rosiclare, Ill., and ad

jacent mining properties.
Protection works:
Length:
Earth levee (new), section 1

2, 421 linear feet.
Earth levee (new), section 2

987 linear feet.

Total.

3, 408 linear feet.
Average height:
Levee, section 1.

19. 5 feet.
Levee, section 2.

22. 3 feet.
Embankment:
Section 1

123, 000 cubic yards.
Section 2.

64, 400 cubic yards.
Drainage structures and storm sewer
alterations...

6,
Movable closures (1 in each section). 2.
Pumping plant, section 1:
Drainage area-

1, 000 acres.
Number..

1.

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Table 8.-Pertinent descriptive da'a, selected plan of improvement,

Rosiclare, N.-Continued
Pumping plant, section 1-Continued
Capacity:
Interior run-off..

35 cubic feet per second.
15, 700 gallons per minute.

0.83 inches per day.
Sanitary sewage.

3 cubic feet per second.

1, 300 gallons per minute. Total.--

38 cubic feet per second.

17, 000 gallons per minute. 57. The structures going through the levee are road-closure structures, storm sewers, and surface-drainage pipes. There is one roadclosure structure in section 1 at the foot of Main Street. Another such closure is provided in section 2 to secure an opening for a railroad track and a road. In section 1, there are three existing storm sewers, 12 inches, 18 inches and 24 inches in diameter, which are carried through the levee by means of cast-iron pipe with seep rings equipped with an automatic gate on the riverside and a vertical-lift gate on the landside. In addition, one opening, 18 inches in diameter, is provided to take surface drainage through the levee. A large drainage outlet, 84 inches in diameter, is provided at Willow Creek. The pipe for these structures is corrugated metal and is equipped with seep rings and automatic gates on the riverside. In section 2 only one outlet, 18 inches in diameter, is required to carry surface drainage through the levee.

58. The total pumping capacity provided by the pumping plant, which is located at Willow Creek, is 38 cubic feet per second or 17,000 gallons per minute, of which 3.0 cubic feet per second is for Sewage disposal and 35 cubic feet per second is for interior run-off disposal. An allowance of 11 cubic feet per second or 5,000 gallons per minute is included in the 35-cubic-feet-per-second figure for mine-pump discharge. In order to take care of this capacity there is provided one 8-inch nonclogging vertical centrifugal pump for sanitary sewage, and three 16-inch vertical axial-flow pumps for interior run-off disposal.

59. No major alterations to existing utilities would be required. However, telephone lines now serving the dwellings and other units which fall outside the protection works require raising to clear the structures. Minor alterations to water service lines to provide continued service to the same units will be necessary.

Alterations to three existing storm sewers to carry them through the levee are required. An access road from the Main Street opening in the floodprotection works to serve units along the riverside of the levee is provided. The railroad spur now serving the coal bin in the vicinity of levee section 2 will be abandoned, and provision is made for the relocation of the coal bin.

60. There is no other water use, such as water supply, power, navigation, etc., with which this plan can be coordinated.

61. Description of alternate plan.-Pertinent physical data for the alternate plan involving a combination of earth levee and concrete flood wall construction is shown in table 9. The general lay-out of the plan is shown on map entitled, “Alternate plan," included in the appendix as plate 1.'

Sot printed.

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