US488422A - System of protecting riparian lands from overflow - Google Patents

Description

n stence of large tide water reservoirs, such as` llnirnn ratas Param lrica,

LINUS WV. BROWN, OF NEW ORLEANS, LOUISIANA.

SYSTEM OF PROTECTING RIPARIAN LANDS FROM OVERFLOW.

SPECIFICATION forming part of Letters Patent No, 488,422, dated December 20, 1892.

Application led August 15,1892. Serial No. 4431077- (NO 111011610 To @ZZ whom t may concern:

Be it known that I, LINUS WV. BROWN, a citi-` zen of the United States, residing at New Orleans, in the parish of Orleans and State of Louisiana, have invented certain new and useful Improvements in Systems of Protecting Riparian Lands from Overiiow; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appert-ains to make and use the same. y

My invention relates to improvements in methods for protecting low-lying lands from the disastrous overflow of rivers and other streams.

This invention is especially adapted to rivers having a considerable difference of level between high and low water, and where the banks are protected from overflow by artificial means, such as levees; and where natura-l` or artificial reservoirs for drawing off the wafter either already exist, or may be conven-` iently created.

My invention is primarily designed for relieving the lower portions of the Mississippi river from disastrous overflow, the level of the land there, being considerably lower than that of the river at high water, andthe eX- Lake Borgne, and Lake Maurepas, in `close proximity to the stream, renderingit possible to construct such works as are hereinafter described within the limits of reasonable ex pense.

The drawings are illustrative of the conditions that prevail in the region of the lower Mississippi, but while designed as especially applicable to the Mississippi river, my invention may be employed wherever suitable conditions exist by nature, or may be created by man.

Reference is had to the accompanying drawings, in which the same words of reference refer to similar parts throughout the several views.

Figure l represents a plan View of a river iiowing in the direction of the arrow l; alake, sea, or other reservoir, not far distant from the said river; anda channelor tail race connectng the two; the said tailrace being bounded by side walls or levees to prevent the lateral iiow of water, and being provided at its end next the river with a non-erosive Weir or dam, of a height slightly less than that of the adjoining levees, which normally keep the river Within its bounds. Fig. 2 represents an enlarged section of Fig. l along lthe line i12-x, and looking in the direction of the arrow 3; and Fig. 3 represents an enlarged section of Fig. l, along the line g/-g/, and looking in the direction of the arrow It.

In the Mississippi river, in recent years, it has been found that the maximum height has been increasing relative to the height of the adjacent lands. Vhether this be due to growing obstructions at its mouth, or to the more rapid drainage of its basin is immaterial as to present purposes; but this increased height of the water can apparently be met in only two ways. First, by steadilyincreasing the height of the levees, already dangerously high; and, second, by furnishing some means for carrying off the superiiuous water.

My invention consists in providing overflow conduits, adapted to carry off the upper layers of water when 'the height exceeds a certain predetermined point. For this purpose I propose to employ artificial channels bounded by side levees to prevent the lateral iiow of the water, connecting the river with some reservoir of large area, preferably one connected directly to the sea. In order that the natural channel of the river may not be disturbed under normal conditions, I propose a Weir or dam preferably faced with brickwork or masonry, and constructed as in Fig. 3, to resist the erosive effect of the water. vWhen the water in the river rises higherthan the top of this Weir it will flow over, and find its way back between the side levees of the reservoir, as shown in Fig. l. Should the level of the river be materially higher than the height of the weir, the water above the weir, and flowing back through the tail race, will be of considerable depth, and will have considerable velocity. Now by having this Weir of sufficient length, the artificial passageway for the Water will be suiicient to carry off .a large proportion of the'total amount of water flowing down the river when it is very high, and will thus preventthe river from rising beyond the height of the Weir, which I shall call the danger line, for all points below the Weir. By having the Weir faced with non-erosive material such as masonry, mattresses of willows, or other equivalent devices, the height of theweir will not be materially changed by erosion, while the overiiowing water will cut one or more channelsin the tail raee,allowinga ready flow back, and preventing undue erosion on the side levees. The said side levees may be facined or otherwiselprotected against erosion, wherever it is found necessary. When practicable, the weir should be preferably constructed in the bend of the river, where the impinging current flows in the direction of the axis of the tail race, as shown in Fig. 1, where the arrows I and 2 indicate the direction of the current in the river and the tail race respectively. It will not be found necessary to build the side levees of the tail race as high near the reservoir as they are near the river.

I am aware that various systems of relieving the Mississippi by means of outlets, have been proposed; but in all of such systems there has been no effort or intention to limit the flow of the water through the outlet to a given height of the river,but on the contrary, it has been proposed to allow the said outlet to cut an enlarging channel for itself. The result of the deepening and enlargening of this channel, would be a slacking up of the water in the portions of the river proper below said channel, causing a deposit of sedimentary matter, the formation of sand bars, and injury to the navigation of the stream, but by limiting the overflow to such times only as the river is dangerously high, the requisite amount of protection is obtained, and at the same time injury to the navigable channel of the river is obviated.

It will be obvious that if it be impracticable to carry off a sufficient amount of water with one long Weir, the number of the said weirs may be increased indefinitely, until the conjoint carrying capacity of the various outlets may equal that desired. Moreover, by having one weir constructed in a series of non-erosive steps from end to end, a graded quantity of water may be carried oif at any and all stages of high water.

Having thus described my invention, what I claim, and desire to secure by Letters Patent of the United States, is:-

1. A means of preventing disastrous overflow to low-lying riparian lands protected by levees, which consists in a portion of said levee lowered, at a bendin the river, and said lowered portion being protected against erosion, and an overflow channel in rear of said lowered portion, openinginto a reservoir of sufficient capacity, substantially as and for the purposes described.

2. The hereinbefore described means for preventing disastrous overflow to low-lying riparian lands protected by levees which consists of a non-erosive weir forming a portion of the line of levees and arranged with its top at a predetermined distance below the tops of said levees, a channel back of said weir, means for confining the water in said channel, and a reservoir of sufficient capacity in rear of said channel, substantially as and for the purposes described.

3. The herein-described means for preventing disastrous overflow to low-lying riparian lands protected by levees, which consists of a Weir forming a portion of the line of levees and arranged with its top at a predetermined distance below the tops of said levees, the said weir and its approaches being protected from erosion by a masonry facing; a channel back of said weir, banks for confining the water in said channel, and a reservoir of sufficient capacity in rear of said channel, substantially as and for the purposes described.

4. The hereindescribed means for preventing disastrous overflow to low-lying riparian lands protected by levees, which consists of a weir forming a portion of the line of levees and arranged with its top at a predetermined distance above low water mark, the said weir and its approaches being protected from erosion by a non-erosive apron sloping to the front and rear; a channel back of said weir; banks for confining the water in said channel, and a reservoir of sufficient capacity in rear of said channel, substantially as and for the purposes described.

In testimony whereof I affix my signature in presence of two witnesses.

LINUS W. BROWN.

Vitnesses:

FELIX J. DREYFoUs, GEO. MONTGOMERY.

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