US3492822A - Tidal flushing system - Google Patents

Description

Feb 3, 1970 w. J. JOSEPHS TIDAL FLUSHING SYSTEM Filed Oct. 26, 1967 Mu x n ma;

wz od a @253 mhiw zmas INVENTOR- Walter J. Josephs BY Attornegs United States Patent O ice 3,492,822 TIDAL FLUSHING SYSTEM Walter J. Josephs, 1924 Courtland Ave., Oakland, Calif. 94601 Filed Oct. 26, 1967, Ser. No. 678,440 Int. Cl. E021! 3/00 US. Cl. 611 8 Claims ABSTRACT OF THE DISCLOSURE A system for the environmental improvement of a bay or similar body of water subject to tidal flow. The system includes a circulation channel extending along the periphery of the bay, with the channel having controllable gates, permitting selective ingress and egress of water to and from the channel. At high tide, for example, water may enter the channel adjacent the closed end of the bay, pass through the channel, and be discharged at the open end of the bay when the water level between the channel and this latter portion of the bay permits such egress. Conversely, water can be accumulated in the channel at high tide at the closed end of the bay and discharged through the same gates at the closed end of the bay at low tide.

In the first instance, improved circulation of the water in the bay will result, and in the second instance, buildup of sand or silt due to incoming tides are pushed back, and a harbor mouth, for example, may be kept open for shipping.

Background of the invention In many instances bays or like bodies of water be come polluted and stagnate, notwithstanding their being subjected to ocean tides. A typical example of such a problem is found particularly in the southern portion of the San Francisco Bay. This bay is relatively long and narrow, and although it is in direct flow communication with the Pacific Ocean through the Golden Gate, there is in fact no effective circulation of water particularly at the southern or closed end of the bay, even though the tides are greater at this portion of bay than at the Golden Gate where clean ocean water regularly enters the bay at high tide. Due to a number of factors, including the time lapse between high tide at the entry to the bay and high tide at the closed end of the bay, there is no appropriate flushing action. Instead, there is only what might be termed a standing wave of stale water which sloshes about, without mixing with the clean ocean water.

Another problem frequently encountered is that of flood waters resulting from rain swollen creeks or streams which discharge into the bay. At high tide particularly, such tributaries will overflow and create substantial problems to the adjacent land masses.

It should be made clear at the outset, that while the particular bay and environment is indicative of San Francisco Bay, the present invention is not intended to be limited thereto, but rather to the general concepts hereinafter set forth in the claims.

Summary of the invention In broad terms, the present invention is directed to the use of a man-made channel extending around the bay in the general shape of a horseshoe. One or more intake control gates are provided along the channel, and the end portions are provided with outfall or discharge gates. The gates may be opened and closed in any conventional manner including the use of differential water pressure or level between the adjacent bay water and the water in the channel.

3,492,822 Patented Feb. 3, 1970 In order to provide for the flushing action water would be permitted to enter the channel through the intake gates at high tide. Such water would flow through the channel towards its ends, and at low tide the outfall ates, would be opened, allowing the water in the channel to enter the bay and be sucked out to sea.

The invention further contemplates the use of the channel and gates for flood control, cleaning silt or sand from an inlet, and cleansing of the channel itself.

Also, there is embraced in this disclosure the use of artificial or man-made islands in a bay to assist in elfecting circulation, agitation and flushing of otherwise stagnant water.

Brief description of the drawings FIGURE 1 is a plan view, somewhat diagrammatic in character, illustrating a bay employing the system of the invention.

FIGURE 2 is a profile chart illustrating the operation of the system relative to tide conditions.

Description of the preferred embodiment As hereinabove suggested, the drawing is generally representative of the southern portion of San Francisco Bay wherein the pollution problem is particularly acute, especially at the closed end portion 6 of the bay. In fact this portion is at the southern end of the bay, rather than at the eastern end as might appear from the drawing. The normal tidal flow at the open end portion 7 of the bay is bidirectional as illustrated at 8, such portion being in communication with the Golden Gate, which is to the left of portion 7, but not shown in the drawing.

As above mentioned, at the portion 7, the tidal flow goes in both directions, i.e., to the right at high tide, and a discharge to the left at ebbing or low tide. However, the closer one approaches to the closed end of the bay, there is no substantial flow or discharge to the left since by the time the high tide reaches portion 6, the differential height differential between portions 6 and 7 is insufiicient to permit proper reverse flow and resulting scavenging or cleansing of the channel.

It should also be pointed out that a number of streams, sloughs, creeks, etc., generally designated by the numeral 9, empty into the bay and create some of the problems above mentioned.

In accordance with the teachings of the present invention, all of the above and other problems normally encountered in this type of bay arrangement are overcome, by first providing a man-made channel 12 extending longitudinally of the bay and which as here shown generally follows the peripheral shore line of the bay. The channel is of generally horseshoe configuration including sides 13 and 14, a loop 16 adjacent the closed bay portion 6, and ends 17 and 18, adjacent the bay inlet 7. The inner and outer channel walls 21 and 22 are sufliciently high so that water from the bay will not overflow into the channel, even at high tide. It will also be noted that the outer Wall of the channel has openings in alignment with the tributaries 9 so that run-off from the latter is directed into channel 12 rather than into the bay. If desired, ship locks 23 may be provided at convenient locations along the channel so as to permit passage of ships between the bay and the tributaries, irrespective of water level differentials.

As an important feature of this invention, a plurality of intake control gates are provided in channel wall 21. Such gates may be normally closed, but when the tide is coming in to the bay, such gates may be opened to permit the incoming tide waters to pass through the gates and enter the channel 12. Preferably, one or more gates 31 are provided at the channel loop 16 with additional gates 32 provided along the channel sides. These gates may be of conventional design and construction and perable in the normal manner for large hydraulic gate members.

At the channel ends 17 and 18, outfall gates 33 are provided generally similar in construction and operation to gates 31 and 32.

In a typical operation for such a system, first assume that all gates are closed and the channel empty of water. As the tide enters the bay, the intake gates 31, and possibly 32 are opened to an extent wherein the water level in the bay exceeds the gate height, so that Water rushes into the channel adjacent the closed end of the bay and will naturally seek its own level throughout the entire length of the channel. This level will correspond to the high tide level of the bay portion 6. Then, when the tide ebbs at the open bay portion 7 to a degree wherein the Water in the channel is higher than the water level at such open bay portion, the outfall gates 33 may be opened, and the water in the channel will rush into the bay and be carried out to the ocean by the ebbing tide. The foregoing will result in a scavenging and proper circulation of the bay waters.

primarily by way of example and not limiting, other than by the scope of the following claims.

What is claimed is:

1. A method of flushing a body of water having a generally continuous shore line and an inlet to such body subjected to tidal flow, which comprises the steps of providing a channel extending from adjacent said inlet towards the other end of said body of water, providing selectively operable gates adjacent opposite ends of said channel with a first gate adjacent said inlet and a second gate adjacent said other end of said body of water, opening said second gate during high tide in said body of water permitting the tide to force water from said body of water through said second gate and into said channel, and then opening said first gate upon ebb tide in said body of water whereby collected water in said channel will be discharged from said channel adjacent said inlet to move with the receding ebb tide.

The channel 12 may likewise be expeditiously utilized for flood control. In the event of excessive rainfall or other conditions leading to an overflowing of the tributaries 9, the intake gates 31 and 32 may remain closed during one or more tides so that the streams, etc. may

discharge into the channel, and the water subsequently discharged through gates 33 during ebb tide at bay portion 7.

A further manner in which the channel and gate arrangement can be used is to accumulate and hold water in the channel and permit the same to escape through the normal intake gates when the water in the bay adjacent such gates is at low tide. Such water action will serve to force silt, sand, etc. away from the closed end of the bay.

To increase the circulation of Water in the bay, there is also disclosed one or more islands or land masses 41 in the bay having both convex and concave shore lines on both sides thereof. Such masses will result in the creation of high velocity areas 42 and 43 on opposed sides of the mass 41 and a turbulent vortex zone 44 downstream of the mass.

The above system also provides for and perm-its creation of boat harbors 51, swimming and recreation areas 52, etc., but since such particular benefits do not constitute a part of this invention, no further discussion is deemed necessary.

FIGURE 2 is a profile, illustrative of the operation of the channel system. The bottom horizontal dashed line 56 represents an arbitrary datum line of zero elevation, with line 57 corresponding to the mean low tide, it being noted that in San Francisco Bay the latter is higher by about 0.1 foot at the bay portion 6 than at the Golden Gate. This differential is accentuated when the mean high tide line 58 is examined, the height of the tide being about 6.7 feet, indicated by vertical line 59 at the Golden Gate,

2. A method as set forth in claim 1 including closing said second gate prior to the opening of said first gate;

3. A method as set forth in claim 1 including closing said first gate at about the time that there is a reversal of tide invsaid body of water adjacent said first gate from a receding ebb tide to an incoming high tide.

4. A method as set forth in claim 1 including closing said second gate at about the time that there is a reversal of tide in said body of water adjacent said second gate from an incoming high tide to a receding ebb tide.

5. A method as set forth in claim -1 and further pro-' viding said channel with a generally U-shaped configuration with the terminal ends thereof on opposed portions of and adjacent said inlet.

6. A method as set forth in claim 1 wherein said body of water has opposed shore portions between said inlet and said other end including the step of providing an island in said body of Water in spaced relation to said opposed shore portions thereof to provide restricted pass-' ages interconnecting said inlet and said other end of said body of Water creating upon an incoming high tide a high velocity water flow through said passages and a turbulent vortex zone intermediate said island and said other end of said body of water.

7. A method as set forth in claim 1 including the step of diverting tributary run-off, which naturally empties into said body of Water, for discharge directly into said channel.

8. A method of flushing a body of Water having agenerally continuous shore line and an inlet to such body subjected to tidal flow, including the steps of providing a channel extending from adjacent said inlet towards the other end of said body of water, providing gates selectively operable independent of fluid flow adjacent opposite ends of said channel with a first gate adjacent said and about 10 feet, indicated by line 61, at the southerly I closed end of the bay and the intake gate 31. The height, represented by line 62, is about 7.6 feet adjacent the bay opening 7 and the outfall gates, and as indicated by line 63, is about 9.4 feet at the intake gates 32. It will be appreciated that even if there is no differential in tide heights between the bay portions 7 and 6, or if the differential is opposite to that above mentioned, the system will nevertheless be operable.

From this profile, the high and lowwater levels in the channels may be determined, as well as the excess tide or water available for ingress through the channel gates 31 and 32 and circulation and discharge through gate 33.

It is intended that the foregoing description will be inlet and a second gate adjacent said other end ofsaid body of water, opening one of said gates and closing the other of said gates at about the time that there is a re versal of tide in said body of water from a receding ebb tide to anincoming high tide, and opening the'other of said gates and closing said one of said gatesat about the time that there is a reversal of tide in said body of water from an incoming high tide to a receding ebb tide.

References Cited UNITED STATES PATENTS 299,559 6/1884 Loretz 612 833,543 10/1906 Parker 611 2,566,447 9/1951 Griswold 61-20 x FOREIGN PATENTS 23,118 1893 Great Britain.

PETER M. CAUN, Primary Examiner

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