Abstract:
An apparatus  40  is used for stabilizing a leak in a dam  20 , which was built adjacent a body of water  26  to prevent flooding of the water onto adjacent land areas  24   a . Leaks in the dam  20  may occur because of a breach  38  developing undesirably in, and possibly through, the dam. The apparatus  40  includes an elastomeric sheet  44 , which is wound onto a spool  48 , when the apparatus is in a storage-and-handling mode. When the breach  38  is discovered, the apparatus  40  is placed adjacent the dam  20  and the sheet  44  is unfurled into a breach-sealing mode of the apparatus, where the breach  38  is covered and sealed by the unfurled sheet.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to apparatus for and methods of stabilizing a leaking dam or levee, and particularly relates to apparatus for and methods of stopping leaks through dams such as, for example, earth dams, typically located along the banks of quiescent bodies of water, and levees along waterways, which contain moving water. 
     A quiescent body of water typically includes lakes, reservoirs, and the like, which are contained within a completely enclosing shoreline, where, normally the water does not escape or flow from within the quiescent body. Waterways of moving water include canals, rivers, and the like, where the water is typically continuously flowing along the banks thereof, which confines the flowing water between the banks, where the flowing water eventually empties into a larger body of water such as, for example, a sea or an ocean. 
     As long as there are no incidents which cause the level of the water to rise in the quiescent bodies and waterways, the water remains within the defined boundaries of the shoreline and banks, respectively. However, weather-related incidents, such as, for example, wind storms and rain, can result in excess amounts of water along at least sections of the quiescent bodies and the waterways, where the water level thereof extends beyond the shoreline and the banks, respectively, resulting in devastating flooding of areas adjacent the bodies and waterways. Such flooding is widely known for causing loss of life and property damage. 
     Naturally formed dams and levees are typically formed as a consequence of flooding over the shoreline and banks, where sediment is deposited, and results in protective barriers which are higher than the floodplain for that area. Man-made dams and levees are constructed purposely to be higher than the floodplains, and may be constructed with concrete, rocks, soil, and the like. Dams and levees formed by compacted soil, and the like, are typically referred to as earth dams and levees, and are susceptible to breaches in the soil, which weaken and erode the protective features of the earth dams and levees. While the major constituent of earth dams is compacted soil, such dams may also include a limited amount of rocks, pebbles, and the like. 
     For purposes of brevity, and not by way of limitation, a dam and a levee will be referred to hereinafter as “a dam.” 
     In the past, as a technique for minimizing, or even preventing, the disasterous flooding events noted above, dams have been built around the quiescent bodies of water, and along the banks of the waterways, to increase the level to which the water is allowed to rise before becoming a flooding threat to nearby people and property. While man-made dams composed of concrete and the like are generally considered as breach-free structures, breaches do occur in such dams, thereby lessening the integrity of the dam. However, as noted above, man-made and natural dams, composed primarily of compacted soil, are particularly susceptible, under the hydrostatic pressure of the contained body of water, to erosion. Such erosion causes leaks through the dams, which could cause the dams to collapse in the vicinity of the erosion. Therefore, earth dams require constant surveillance, and repair, to maintain the integrity of such dams. 
     Consequently, there is a need for an apparatus for, and methods of, facilitating the stopping of the undesirable leakage of water within, and through, a breach in the structure of a dam to maintain and stabilize the integrity of the dam for continued use. 
     Further, there is a need for an apparatus for, and methods of, facilitating temporary stopping of the undesirable leakage of water within, and through, a breach in the structure of a dam to preclude the flow of water through the breach, and to maintain and stabilize the integrity of the dam, during a period when the breach-containing portion of the dam is being repaired. 
     An article, written by Mike Field, titled, “Fragile Foundations,” which appeared in “Johns Hopkins Engineering, The Magazine of the Johns Hopkins Whiting School of Engineering, ” Winter 2010, starting on page 12, refers to the biennial report card of the American Society of Civil Engineers on the state of America&#39;s infrastructure in 2009, including dams and levees. As noted in the article, “Thousands of the nation&#39;s dams, for instance, are rated structurally deficient, and no fewer than 1800 of those are rated “high hazard” dams, meaning their catastrophic failure would result in significant loss of life.” 
     In today&#39;s economic climate, it is highly unlikely that such a large infrastructure investment will be made. 
     Consequently, there is a need for a relatively low cost apparatus for and methods of facilitating the stabilization and maintenance of the nation&#39;s dams, particularly during a period when it appears that high-cost repairs and reconstruction to such “high hazard” dams may not be forthcoming. 
     As shown and described in U.S. Pat. No. 4,184,786 (the &#39;786 patent), which issued on Jan. 22, 1980, a water-impervious, flexible cover is placed over surfaces of an earth dam to protect vulnerable surfaces of the dam from developing breaches. The cover extends over at least the top surface and the downstream surface of the dam, and preferably extends over the upstream surface of the dam as well. Also, the cover extends to, and is anchored at the bed of the body of the water on the downstream side of the dam, and to the ground on the upstream side of the dam. Such an extensive cover for an entire dam would be very costly in order to protect the entire dam in the manner described in the &#39;786 patent. 
     Thus, there is a need for cost-effective apparatus of and methods for stabilizing an earth dam in the event of a leak through a breach in the dam. 
     Also, the type of material of the cover, as described in the &#39;786 patent, is an organic material which may become brittle and crack under prolonged exposure to the environment, including debilitating stresses to which a cover for an earth dam is typically subjected. In particular, organic materials soften and deform irreversibly at temperatures greater than 100° C., and become brittle at temperatures less than −25° C. 
     Thus, there is a need for an apparatus of and methods for stabilizing an earth dam wherein the material of critical portions of the apparatus are capable of maintaining structural resiliency and integrity when subjected to here-to-fore potentially debilitating stresses. 
     SUMMARY OF THE INVENTION 
     It is, therefore, an object of this invention to provide an apparatus for, and methods of, facilitating the stopping of the undesirable leakage of water within, and through, a breach in the structure of a dam to maintain and stabilize the integrity of the dam for continued use. 
     Another object of this invention is to provide an apparatus for, and methods of, facilitating temporary stopping of the undesirable leakage of water within, and through, a breach in the structure of a dam to preclude the flow of water through the breach, and to maintain and stabilize the integrity of the dam, during a period when the breach-containing portion of the dam is being repaired. 
     A further object of this invention is to provide a relatively low cost apparatus for and methods of facilitating the stabilization and maintenance of the nation&#39;s dams, particularly during a period when high-cost repairs and reconstruction to such dams may not be available. 
     Another object of this invention is to provide a cost-effective apparatus of and methods for stabilizing an earth dam in the event of a leak through a breach in the dam. 
     A still further object of this invention is to provide an apparatus of and methods for stabilizing an earth dam wherein the material of critical portions of the apparatus are capable of maintaining structural resiliency and integrity when subjected to heretofore potentially debilitating stresses. 
     With these and other objects in mind, this invention contemplates an apparatus for stabilizing a leak in a dam or a levee, which includes a flexible sheet composed of a material capable of withstanding hydrostatic water pressure in a body of water without rupturing. The flexible sheet is manipulatable for positioning breach-sealable portions of the sheet over a breach in the dam or the levee into which the leak could flow. The flexible sheet is composed of an inorganic material which maintains consistent flexibility and resilience when subjected to temperatures within a range from −100° C. to 316° C. 
     This invention also contemplates a portable and reusable apparatus for covering and stabilizing an existing breach located in an unprotected portion of a dam or a levee to preclude a leak of water, into the breach, from a body of water adjacent the dam or the levee. The apparatus includes a flexible sheet composed of a material which is impervious to water, and has a proximal portion and a distal portion spaced from the proximal portion thereof. Means are attached to the proximal portion of the flexible sheet for facilitating handling of the flexible sheet. A portion of the flexible sheet is sufficiently supple to allow the portion of the flexible sheet, when placed over the breach in the dam or levee, to be urged into, and seal, the breach to preclude a leak of the water into the breach. 
     This invention further contemplates a portable and reusable apparatus for covering and stabilizing an existing breach located in an unprotected portion of a dam or a levee to preclude a leak of water, into the breach, from a body of water adjacent the dam or the levee, and includes a flexible sheet having a proximal end and a distal end. The flexible sheet further includes an intermediate section which extends between the proximal end and the distal end spaced from the proximal end thereof. The flexible sheet is composed of a material which is impervious to water, and which is sufficiently supple to cover and seal the breach from the body of water. A rotatable spool is coupled to the proximal end of the flexible sheet for rotation relative to the flexible sheet. The apparatus also includes at least one cord which has a proximal end, a distal end and an intermediate section. 
     The proximal end of the cord is attached to the rotatable spool, the distal end of the cord is attached to the proximal end of the flexible sheet, and the intermediate section of the cord extends from the proximal end thereof over an outboard major surface of the flexible sheet, about the distal end of the flexible sheet, and over an inboard major surface of the flexible sheet, and to the distal end of the cord. The spool is rotatable relative to the flexible sheet to facilitate selective movement of the cord in opposite directions during movement of the flexible sheet between a storage-and-handling mode and a breach-sealing mode, and vice-versa. 
     This invention still further contemplates a method of covering and stabilizing an existing breach located in an unprotected portion of a dam or a levee to preclude a leak of water, into the breach, from a body of water adjacent the dam or the levee. The steps of the method include (1) providing a water-impervious flexible sheet having a proximal end, a distal end and an intermediate section extending between the proximal end and the distal end spaced from the proximal end thereof, (2) storing the flexible sheet in the form of a full package when the flexible sheet is in a storage-and-handling mode, (3) unfurling a proximal portion the flexible sheet extending from the proximal end of the flexible sheet from the the package while retaining the remainder of the flexible sheet in a less-than-full package, (4) placing the less-than-full package of the remainder of the flexible sheet into the body of water, and (5) unfurling at least a portion of the water-bound less-than-full package of the flexible sheet sufficient for a breach-sealing portion of the flexible sheet to cover the breach, whereby the flexible sheet is in a breach-sealing mode. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a sectional view showing the cross sectional shape of compacted soil which forms an earth dam along a bank of a body of water; 
         FIG. 2  is a sectional view showing a breach formed in a water-covered side of the earth dam of  FIG. 1 , allowing a leak to form through the dam, whereby water, from the body of water normally confined by the dam, to leak into, and through, the breach, under the hydrostatic pressure of the body of water, to an uncovered side of the dam opposite the water-covered side thereof, and an end view showing an apparatus for stabilizing the leak, with the apparatus shown in a pre-stabilization, storage-and-handling mode in preparation for placing the apparatus in a stabilizing, breach-sealing mode, in accordance with certain principles of the invention; 
         FIG. 3  is a sectional view showing the apparatus of  FIG. 2  placed in a stabilizing, breach-sealing mode for covering and sealing the breach on the water-covered side of the dam, in accordance with certain principles of the invention; 
         FIG. 4  is a perspective view showing the apparatus of  FIGS. 2 and 3  with a flexible sheet of the apparatus being unfurled, open and flattened representing the apparatus in the stabilizing, breach-sealing mode, as shown in  FIG. 3 , to seal the breach in the water-covered side of the dam, in accordance with certain principles of the invention: and 
         FIG. 5  is a partial perspective view showing elements of the apparatus of  FIGS. 2 ,  3  and  4 , which are operational to facilitate (1) the packaging of the flexible sheet to place the apparatus in the storage-and-handling mode, as shown in  FIGS. 2 , and (2) the unfurling of the flexible sheet to place the apparatus in the breach-sealing mode, as shown in  FIGS. 3 and 4 , in accordance with certain principles of the invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIG. 1 , an earth dam  20  is formed with a mound-like cross section, and is composed of compacted soil  22 , which could include limited amounts of rock and pebble. The earth dam  20  is located along the shoreline or bank  24  of a body of water, hereinafter referred to as the water  26 . The bank  24  is formed by an upper level of a land mass  28 , with a depression in the land mass forming a bed  28   a  for the water  26 . The water  26  may be quiescent, such as, for example, in a lake, or moving, such as, for example, in a canal. The earth dam  20  is formed with a water-covered side  30 , which is in engagement with the water  26 , and an uncovered side  32 , which is on a side of the dam opposite from the water-covered side. The earth dam  20  must be of sufficient integrity to withstand the hydrostatic pressure exerted thereon by the water  26 . 
     Normally, the upper level of the water  26  will be below the bank  24 , as illustrated by the dashed line  34  in  FIG. 1 . Under this circumstance, the water  26  is contained, and will not flow over areas higher than the bank  24 . However, extreme weather conditions such as, for example, wind and rain, could cause the water  26  to rise to a level higher than the bank  24 , which level is well above the level of the bank. In this situation, the water  26  will flow over the bank  24 , and onto land areas  24   a , resulting in undesirable flooding of such land areas, and the possibility of property damage and loss of life. 
     The dam  20  is located on the bank  24 , and has a peak, or top,  42  built to a height sufficient to allow the water  26  to rise to levels higher than the bank, and to a higher limit defined by the height of the peak, above which the water would overflow the dam and flood the land areas  24   a.  One such higher level is illustrated as a level  36 , which precludes the water from flowing onto, and preventing the flooding of, the land areas  24   a.    
     Referring to  FIG. 2 , frequently, at least along some portions of the water-covered side  30 , the integrity of the earth dam  20  cannot withstand the hydrostatic pressure of the water  26 , and a breach  38  or fissure is formed in the water-covered side. The water  26  entering the breach  38  erodes the surrounding walls of the breach, and extends the length of the breach toward the uncovered side  32  of the dam  20 . Eventually, the breach  38  is formed completely through the earth dam  20 , as illustrated in  FIG. 2 , whereafter the water  26  flows from the breach, down the uncovered side  32 , and onto the land area  24   a . A continuation of the flow of the water  26  through the breach  38 , and onto the land area  24   a , could result in serious damage to the earth dam  20 , eventually leading to the collapse of the dam in the vicinity of the breach, and flooding of the land area well beyond the uncovered side  32  of the dam. As noted above, this could lead to loss of life and property damage. 
     As a consequence of one or more breaches, such as the breach  38 , in the structure of the earth dam  20 , constant inspections should be conducted to note such breach failures, and to allow adequate time (1) to stem the deleterious effects of the breach, and (2) to repair the resulting damage, prior to the occurrence of damaging floods in surrounding neighborhoods. 
     As shown in  FIG. 2 , an apparatus  40  for stabilizing a leak, such as the breach  38  in the dam  20 , is shown in a pre-stabilization, storage-and-handling mode, and is resting on the peak  42  of the dam  20  in preparation for initiating a process to place the apparatus into a stabilizing, breach-sealing mode. 
     As shown in  FIG. 4 , the apparatus  40 , for stemming the deleterious effects of the above-noted breach  38  ( FIG. 2 ), includes a flexible sheet  44  formed from a flexible material, which is impervious to water, and is of sufficient strength to preclude rupture thereof when the material is subjected to the hydrostatic pressure of the water  26  ( FIG. 2 ), including being sufficiently supple at the location of the breach-sealing portion thereof to be urged into, and seal, the breach without rupture. 
     In addition, the material of the flexible sheet  44  has sufficient density and weight to allow it to sink, on its own, without additional assistance, when placed in the body of the water  26 , and is sufficiently flexible to be manipulatable for positioning breach-sealing portions thereof over the breach in the dam into which the leak could otherwise flow. Further, the material of the flexible sheet  44  is an elastomer, such as, for example, silicone rubber, which has suitable weight and durometer to function in the manner noted herein. 
     The flexible sheet  44  may be composed of materials other than an elastomer, provided that all of the specifications are met, without departing from the spirit and scope of the invention. Also, the material of the flexible sheet  44  is an inorganic material which maintains consistent flexibility and resilience when subjected to temperatures within a range between −100° C. to 316° C. 
     A material which has the above-noted properties for the flexible sheet  44 , of this invention, is silicone rubber, which is a synthetic elastomer available from Dow Corning Corporation, having an address at 3901 S. Saginaw Road, Midland, Mich. 48640, under the SILASTIC® and XIAMETER® brands, which are trademarks owned by Dow Corning Corporation. 
     While the flexible sheet  44  can assume any flattened shape desired during the period when the apparatus  40  is in the breach-sealing mode to stem the deleterious effects of the breach  38  ( FIG. 2 ), it will be assumed, for purposes of description, that the sheet is in the shape of a rectangle when opened or flattened, as shown in  FIG. 4 . Other shapes of the sheet  44 , when flattened or otherwise, can be used without departing from the spirit and scope of the invention. 
     As shown in  FIG. 2 , the sheet  44  of the apparatus  40  is of sufficient flexibility to allow the sheet to be manipulated into a storage package in a configuration of a sheet-storage roll  46 , when the apparatus is in the storage-and-handling mode, to facilitate easy storage, portability, and handling of the apparatus during periods when the apparatus is not being used to stem the deleterious effects of the breach  38 . The storage package can assume other configurations, other than the sheet-storage roll  46 , without departing from the spirit and scope of the invention. 
     Many earth dams in the world are less than fifty feet in height, but earth dams having a height of several hundred feet do exist. Consequently, the apparatus  40  can be made with the flexible sheet  44  being of a sufficient length to accommodate the stabilization of a leak in dams of heights of several hundred feet and higher. 
     It is noted that the thickness “T” of the flexible sheet  44  ( FIG. 5 ) is in a range between 0.015 inch and 0.030 inch, with the thickness of the sheet being 0.020 inch in the preferred embodiment of the invention. 
     As further shown in  FIG. 4 , the apparatus  40  is in the breach-sealing mode, with the flexible sheet  44  being in an open, unfurled, flat arrangement, and having a distal end  44   a , a proximal end  44   b , and an intermediate section extending between the distal and proximal ends. The distal end  44   a  of the sheet  44  is attached, by fasteners  47 , to a support spool  48  composed of a material which is impervious to water. The spool  48  is a weight, which will sink in water on its own. The spool  48  provides a support upon which the flexible sheet  44  can be wrapped, or wound about, to form the sheet-storage roll  46  ( FIG. 2 ), and also functions as the weight which assists in the sinking of the flexible sheet into the water  26 . 
     Referring to  FIGS. 4 and 5 , the proximal end  44   b  of the flexible sheet  44 , which is parallel with and spaced from the distal end  44   a , is secured to a stiffening support assembly  50 , which includes a first support bar  52  having the proximal end of the flexible sheet attached thereto. The stiffening support assembly  50  may also include a second support bar  54 , which is placed in overlaying fashion with the first support bar  52 , with the proximal end  44   b  of the sheet  44  being sandwiched between, and secured to, the stiffening support assembly formed by the first and second support bars. 
     The first support bar  52  and the second support bar  54  function individually, or collectively, as a means attached to the proximal end  44   b  of the flexible sheet  44  for facilitating handling of the flexible sheet. 
     As shown in  FIG. 5 , internal structure  44   e  of the flexible sheet  44  is shown with solid cross-hatching at three different locations, to illustrate that the internal structure is solid, unwoven, self-supporting, and is free internally of any physical support structure independent of the silicone rubber of the flexible sheet. 
     A rotatable spool  56  is located adjacent, and parallel with, the stiffening support assembly  50 , and is mounted for rotation within, and relative to, a pair of spaced bearings  58  and  60  ( FIG. 4 ). The bearing  58  is formed integrally with a flange pad  62 , which extends radially outward from an outer surface of the bearing. In like fashion, as shown in  FIG. 4 , the bearing  60  is formed integrally with a flange pad  64 , which extends radially outward from an outer surface of the bearing. Each of the pads  62  and  64  is formed with a through hole, such as, for example, the through hole  66  ( FIG. 5 ). The pads  62  and  64  are mounted at spaced locations on an outboard surface  52   a  of the first support bar  52 , with the through holes  66  thereof being aligned with aligned holes (not shown) formed through the first support bar, the sheet  44 , and the second support bar  54 . A pair of threaded bolts, one shown as a bolt  70  in  FIG. 5 , are positioned through the aligned holes of the respective pads  62  and  64 , the first support bar  52 , the sheet  44 , and the second support bar  54 , and are threadedly assembled with a respective pair of nuts, one shown as a nut  72  in  FIG. 5 , to secure the bearings  58  and  60  with the stiffening support assembly  50  and the sheet  44 . Other types of fasteners may be used in place of the bolt  70  and nut  72  without departing from the spirit and scope of the invention. 
     The first support bar  52  is formed with a plurality of holes  74 , which align with corresponding holes (not shown) of the sheet  44  and the second support bar  54 , to receive securing spikes  76  ( FIG. 5 ), or similar fasteners. The spikes  76  are driven into a fixed structure, such as, for example, the soil  22  at the peak  42  of the dam  30  to secure the apparatus  40  in the storage-and-handling mode illustrated in  FIG. 2 , in preparation for eventually placing the sheet  44  in the breach-sealing mode. The apparatus  40  could be secured to other nearby fixed structures, or to other surface portions of the dam  20 , exclusive of the water-covered side  30  of the dam which is in engagement with the water  26 , without departing from the spirit and scope of the invention. 
     Referring further to  FIGS. 4 and 5 , the apparatus  40  includes a first roll-up retaining cord  78 , which is in a looping arrangement about, but not secured to, the flexible sheet  44 , as best viewed in  FIG. 4 , with the flexible sheet completely unfurled. A first end  78   a  of the cord  78  is secured to a location  56   a  on the outer surface of the rotatable spool  56 , adjacent the bearing  58 . The cord  78  is then extended through a latching device  82 , mounted on the outboard surface  52   a  of the first support bar  52 , over a major outboard, or water-side, surface  44   c  of the sheet  44 , around the distal end  44   a  of the flexible sheet, which is attached to the spool  48 . The cord  78  is then extended along a major inboard, or dam-side, surface  44   d  of the sheet  44 , which is on the side of the sheet opposite the major outboard surface  44   c.  A second end  78   b  of the cord  78  is attached, for example, to an eyelet  85 , which is attached to a side face  54   a  of the second support bar  54 , as shown in  FIG. 5 . 
     As shown in  FIG. 5 , the latching device  82  includes a housing  84 , within which is a smooth-faced roller (not shown), over which the first retaining cord  78  will move when the sheet  44  is being unfurled to the breach-sealing mode, or wound onto the spool  48  to form the sheet-storage roll  46  ( FIG. 2 ) in the storage-and-handling mode. The smooth-faced roller is attached to a slide bar  86 , located on an exterior surface of the housing  84 , with portions (not shown) extending through a slot  88  formed in the housing, and attached to the smooth-faced roller within the housing. When the apparatus  40  is in the storage-and-handling mode, the slide bar  86  is moved in a first direction, relative to the slot  88 , to sandwich the cord  78  between the roller and an interior wall (not shown) of the housing  84 , and the slide bar is latched in this position by a mechanism (not shown). In this manner, the cord  78  is prevented from unreeling from the spool  56 , and the apparatus  40  is retained in the storage-and-handling mode. A hand force can be applied to the slide bar  86  in a second direction, which is a direction opposite the first direction, to overcome the latching of the slide bar  86 , and to allow the sheet  44  to unfurl. 
     Referring to  FIG. 4 , the apparatus  40  also includes a second roll-up retaining cord  90  which is secured at a first end  90   a  thereof to a location  56   b  on the outer surface of the rotatable spool  56 , adjacent the bearing  58 . The cord  90  is then extended through a latching device  92 , mounted on the outboard surface  52   a  of the first support bar  52 , over the unfurled surface  44   c  of the sheet  44 , around the extended remainder portion of the sheet wound on the spool  48 , and any exposed portions of the spool. The cord  90  is then extended along the underside surface  44   d  of the sheet  44 , with a second end (not shown) of the cord being attached, for example, to an eyelet (not shown), which is attached to the side face  54   a  ( FIG. 5 ) of the second support bar  54 . 
     In a manner identical to the latching device  82  ( FIG. 5 ), the latching device  92  includes a housing, within which is a smooth-faced roller (not shown), over which the second roll-up retaining cord  90  will move when the sheet  44  is being unfurled into the breach-sealing mode, or wound onto the spool  48  to form the sheet-storage roll  46  ( FIG. 2 ) in the storage-and-handling mode. The smooth-faced roller is attached to a slide bar (not shown), located on an exterior surface of the housing, with portions (not shown) extending through a slot (not shown) formed in the housing, and attached to the smooth-faced roller within the housing. When the apparatus  40  is in the storage-and-handling mode, the slide bar of the latching device  92  is moved in a first direction, relative to the slot formed in the housing  94  to sandwich the cord  90  between the roller and an interior wall (not shown) of the housing, and the slide bar is latched in this position by a mechanism (not shown). In this manner, the cord  90  is prevented from unreeling from the spool  56 , and the apparatus  40  is retained in the storage-and-handling mode. A hand force can be applied to the slide bar of the latching device  92  in a second direction, which is a direction opposite the first direction, to overcome the latching of the slide bar, and to allow the sheet  44  to unfurl. 
     It is noted that the structure, the assembly arrangement, and the interrelated functioning of the bearing  60  and the flange pad  64 , the roll-up retaining cord  90 , the latching device  92 , and the elements associated therewith, shown in  FIG. 4 , are a mirror image of the structure, the assembly arrangement, and the interrelated functioning of the bearing  58  and the flange pad  62 , the roll-up retaining cord  78 , the latching device  82 , and the elements associated therewith, respectively, shown in  FIG. 5 , and described herein above. 
     It is further noted that means for maneuvering the flexible sheet  44  from a breach-sealing mode into a storage package in a storage-and-handling mode includes the cord  78 , the rotatable spool  56 , the attachment of the proximal end  78   a  of the cord to the rotatable spool, the distal end  78   b  of the cord attached to the second support bar  54  (or the first support bar  52 ), the looping arrangement of the cord about the flexible sheet as described above, and about the distal end  44   a  of the flexible sheet, and to the distal end of the cord. 
     Referring to  FIG. 4 , a crank  96  is formed with an “L” shaped arm  98 , having a first leg  98   a  joined integrally with a second leg  98   b.  A knob  100  is attached to a free end of the first leg  98   a , and a free end of the second leg  98   b  is selectively attachable to, and in axial alignment with, an end  102  of the spool  56 . When it is desired to transform the apparatus  40  from the breach-sealing mode, as shown in  FIG. 4 , to the storage-and-handling mode, as shown in  FIG. 2 , the free end of the second leg  98   b  of the crank  96  is attached, axially, to the end  102  of the spool  56 . The crank  96  is then rotated, in a prescribed direction, about the axis of the spool  56  to rotate the spool and wind the cords  78  and  90  onto the spool. By virtue of the cords  78  and  90  being wound onto the spool  56 , the spool  48  is moved linearly toward the spool  56 , and is also rotated to facilitate the winding of the sheet  44  about, and onto, the spool  48 . Eventually, the sheet  44  is fully wound onto the spool  48 , which has now been moved to the storage-and-handling mode of the apparatus  40 , as illustrated in  FIG. 2 . 
     As an alternative to the crank  96 , a drive shaft  104  of a small electrical motor  106  may be attached axially to the end  56   b  of the spool  56 , in place of the crank  96 , and the motor controlled to accomplish the transformation of the apparatus  40  from the breach-sealing mode to the storage-and-handling mode in the manner described above with respect to use of the crank. 
     Without departing from the spirit and scope of the invention, (1) the motor 106 could be battery-operated, or powered from an independent power source, (2) the motor could be a reversible motor, and (3) the crank  96  could be rotatable about the axis of the spool  56  in a clockwise direction and a counter-clockwise direction. Both the crank  96  and the motor  106 , when attached to the spool  56 , are considered to be a part of the apparatus  40 . 
     A cord moving mechanism includes the rotatable spool  56 , mounted for rotating movement at least within the bearing  58 , which, through the support bar  52 , is attached to the proximal end  44   b  of the flexible sheet  44 . The cord moving mechanism may also include the mounting of the rotatable spool  56  within the bearing  60  in similar fashion. Each of (1) means for operating the cord moving mechanism to move the cord  78  in a direction to maneuver the flexible sheet  44  from the breach-sealing mode to the storage-and-handling mode, and (2) means for operating the cord moving mechanism to move the cord  78  in a direction to maneuver the flexible sheet  44  from the storage-and-handling mode to the breach-sealing mode, and (3) means for moving the spool  56  to move the cord  78 , include the crank  96  or the motor  106 . 
     The unfurling of the sheet  44  from the storage-and-handling mode to the breach-sealing mode may be accomplished without the use of the crank  96  or the motor  106  by allowing the spool  48  and the sheet wound thereon to roll, by gravity or manual assistance, down a sloped surface such as, for example, the water-covered side  30  of the dam  20 . However, the crank  96  or the motor  106  could be used to control the unfurling of the sheet  44  if desired, or necessary, without departing from the spirit and scope of the invention. 
     Referring again to  FIG. 2 , a repairman, or inspector, may discover the breach  38  by virtue of the water  26  exiting from the breach on the uncovered side  32  of the dam  20 . It is possible that, if the breach  38  does not extend to the uncovered side  32  of the dam  20 , the repairman could also initially discover the breach  38  by inspecting the water-side  30  of the dam  20 . Regardless of the manner of discovering the breach  38 , the breach should be stabilized on the water-covered side  30  of the dam  20 , to stem the leak. If desired, the dam  20  can then be repaired in the area of the breach  38 , without concern for the water  26  entering, and flowing through, the breach, during the repair operation. 
     Referring to  FIG. 2 , after observing the breach  38 , the repairman transports the apparatus  40 , while in the storage-and-handling mode, to a position for eventually covering the breach when the sheet  44  is unrolled, or unfurled, into the water  26 . The apparatus  40  is placed on, or near, an upper portion of the earth dam  20 , with the support assembly  50  resting on the dam. The support assembly  50  is then secured to the dam  20  by use of the above-noted spikes  76 . The rolled sheet  44  is then maneuvered to the upper edge of the water-covered side  30  of the dam  20 , and is released, or unfurled, to roll, by gravity, down the water-covered side. The ability of the flexible sheet  44  to sink in water, and the weight of the spool  42 , facilitates the unrolling movement of the sheet  44  down the water-covered side  30  of the dam  20 , and the sinking of the spool with the sheet, into the water  26 , until such unrolling, or unfurling, movement is complete. It is noted that, as described above, the sheet  44  is of sufficient weight to facilitate the sinking of the sheet into the water  26 , independently of the weight of the spool  48 . 
     In the above-described process, the flexible sheet  44  is initially stored in the form of a full package, such as the sheet-storage roll  46 . After the apparatus  40  has been placed on, and secured to, the top  42  of the dam  20 , the unfurling of the sheet  44  is initiated, where a proximal portion of the sheet is initially unfurled from the proximal end  44   b  of the full package. Thus, a portion of the full package of the flexible sheet  44  has been unpackaged, or unfurled, but a remainder of the flexible sheet remains in a package form, which is less than the full package, and is referred to a less-than-full package. The less-than-full package of the flexible sheet  44  is then placed into the water  26  as a water-bound less-than-full package, and the sheet continues to be unfurled within the water from the less-than-full package. 
     If the breach  38  is located at a portion of the water-covered side  30  of the dam  20 , at a distance from the top  42  of the dam which is less than the total length of the flexible sheet  44 , only a portion of the water-bound less-than-full package of the sheet need be unfurled in order to place the sheet in a breach-sealing mode, with a breach-sealing portion covering the breach. This limited, or less-than-full, amount of unfurling of the flexible sheet  44  can be controlled by limiting the number of rotations of the rotatable spool  56  during the unfurling operation, which can be accomplished by hand, by use of the crank  96 , or by use of the reversible motor  106 . 
     During the unrolling, or unfurling, movement, the sheet  44  is located against the adjacent portion of the water-covered side  30  of the dam  20 , with a portion of the sheet being located over the breach  38  formed in the water-covered side of the dam. The above-noted physical properties of the elastomeric sheet  44  are such that the hydrostatic pressure of the water  26  urges the sheet into conforming engagement with the adjacent portion of the water-covered side  30  of the dam  20 . 
     With a portion  44   e  of the now-flattened sheet  44  is located over the breach  38  on the water-covered side  30  of the dam  20 , as shown in  FIG. 3 , the hydrostatic pressure of the water  26  will urge and deform the located portion  44   e  of the sheet into sealing arrangement with the breach, and preclude the flow of the water into the breach. Consequently, the leak in the dam  20  is stabilized, and concern for further erosion is mitigated. Repairmen can then reconstruct, and/or repair, the breached portion of the earth dam  20 . The earth dam  20  is again in condition to preclude the flow of the water  26  through the dam, whereby devastating flooding is avoided. 
     The apparatus  40  can then be removed from the water  26  by a use of the crank  96 , or the motor  106 , in the manner described above. As the sheet  44  is removed from the water  26 , the sheet is manipulated into the form of a storage package, which, in the preferred embodiment of the invention, is the rolled position about the spool  48 , as shown in  FIG. 2 . The apparatus  40 , now in the storage-and-handling mode, can then be stored at a suitable location for use to repair other breaches of the earth dam  20 . Due to the versatility and easy handling of the apparatus  40 , the apparatus need not be stored at each earth dam  20 , but could be stored at a strategic location for quick availability. Further, there is no limitation to the length and width of the sheet  44 , which can be based on the needs of the repairmen, and the height of the dam  20 . 
     The above-noted physical properties of the elastomeric material, which forms the sheet  44 , and which facilitates the stabilizing of the leaking dam  20 , include (1) a suitable durometer and elasticity so that the sheet conforms to contours and irregularities of the water-covered side  30  of the dam, (2) suitable low-temperature flexibility to allow for the use of the material at freezing temperatures, (3) suitable structural strength to maintain integrity while adhering to the water-covered side  30  of the dam and to allow for intact removal, (4) suitable structural strength such that supporting structures along the sides of the sheet, other than at the top and bottom thereof, are not required during the use of the apparatus  40 , which facilitates the capability of rolling and unrolling of the sheet, and (5) suitable density to facilitate the sinking of the sheet and the continued submergence thereof during the stabilizing use of the apparatus. 
     In general, the above-identified embodiments and procedures are not to be construed as limiting the breadth of the present invention. Modifications, and other alternative constructions and procedures, will be apparent which are within the spirit and scope of the invention.