U.S. patent application number 15/049990 was filed with the patent office on 2017-08-24 for small stream fish ladder.
The applicant listed for this patent is South Dakota State University. Invention is credited to Katie N. Bertrand, Brian D. S. Graeb, John A. Lorenzen.
Application Number | 20170241093 15/049990 |
Document ID | / |
Family ID | 59629691 |
Filed Date | 2017-08-24 |
United States Patent
Application |
20170241093 |
Kind Code |
A1 |
Bertrand; Katie N. ; et
al. |
August 24, 2017 |
SMALL STREAM FISH LADDER
Abstract
A fish ladder for small-bodied fishes that is easily portable so
as to enable installation and use in a given water course when
needed, and relocation at other times. The fish ladder defines a
channel with generally evenly spaced baffles in the channel
disposed at about 45.degree. angles to the channel bottom. The
ladder includes a bracket that enables the ladder to be attached to
any size, shape, and material of culvert or other drainage
structure. The ladder is attached to the bracket with a hinge
mechanism, so as to accommodate virtually any height of drop
presented by small drainage structures. With extendable legs, a
fish ladder according to embodiments of the invention is able to be
installed in streams up to 6 feet deep. The ladder can be scaled so
as to target passage of small-bodied non-game species such as
minnows, while also passing larger game species as well.
Inventors: |
Bertrand; Katie N.;
(Brookings, SD) ; Graeb; Brian D. S.; (Nunda,
SD) ; Lorenzen; John A.; (Holstein, IA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
South Dakota State University |
Brookings |
SD |
US |
|
|
Family ID: |
59629691 |
Appl. No.: |
15/049990 |
Filed: |
February 22, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
Y02A 40/60 20180101;
E02B 8/085 20130101 |
International
Class: |
E02B 8/08 20060101
E02B008/08 |
Claims
1. A fish ladder comprising: a structure interface adapted to
attach to a drainage structure, the structure interface portion
including a weir plate; and a ladder defining a channel for
conveying water in a flow direction, the ladder including a
plurality of baffles disposed across the channel generally
transverse to the flow direction, the ladder operably coupled to
the interface structure with a detachable hinged connection.
2. The fish ladder of claim 1, wherein the detachable hinged
connection comprises at least one hinge pin receiver on the
structure interface, the at least one hinge pin receiver defining a
first bore, a pin receiving sleeve on the ladder, the pin receiving
sleeve defining a second bore, and a hinge pin received through the
first bore and the second bore.
3. The fish ladder of claim 2, wherein the ladder is shiftable
about the hinge pin between a first position in which the ladder
extends in a horizontal orientation from the structure interface
and a second sloped orientation in which the ladder slopes
downwardly from the structure interface.
4. The fish ladder of claim 1, wherein the channel is defined by a
pair of spaced apart substantially parallel side panels and a
bottom panel extending between the side panels.
5. The fish ladder of claim 1, wherein the baffles are angled
rearwardly toward the structure interface.
6. The fish ladder of claim 5, wherein the baffles are angled at
about 45 degrees relative to a bottom of the channel.
7. The fish ladder of claim 1, further comprising at least one
support leg adapted to attach to the ladder.
8. The fish ladder of claim 7, wherein a length of the support leg
is adjustable.
9. A system for enabling fish migration comprising: a drainage
structure; and a fish ladder operably couplable to the drainage
structure, the fish ladder comprising: a structure interface
adapted to attach to the drainage structure, the structure
interface portion including a weir plate; and a ladder defining a
channel for conveying water in a flow direction, the ladder
including a plurality of baffles disposed across the channel
generally transverse to the flow direction, the ladder operably
coupled to the interface structure with a detachable hinged
connection.
10. The system of claim 9, wherein the detachable hinged connection
comprises at least one hinge pin receiver on the structure
interface, the at least one hinge pin receiver defining a first
bore, a pin receiving sleeve on the ladder, the pin receiving
sleeve defining a second bore, and a hinge pin received through the
first bore and the second bore.
11. The system of claim 10, wherein the ladder is shiftable about
the hinge pin between a first position in which the ladder extends
in a horizontal orientation from the structure interface and a
second sloped orientation in which the ladder slopes downwardly
from the structure interface.
12. The system of claim 9, wherein the channel is defined by a pair
of spaced apart substantially parallel side panels and a bottom
panel extending between the side panels.
13. The system of claim 9, wherein the baffles are angled
rearwardly toward the structure interface.
14. The system of claim 13, wherein the baffles are angled at about
45 degrees relative to a bottom of the channel.
15. The system of claim 9, further comprising at least one support
leg adapted to attach to the ladder.
16. The system of claim 15, wherein a length of the support leg is
adjustable.
17. A fish ladder comprising: a structure interface adapted to
attach to a drainage structure, the structure interface portion
including a weir plate presenting a top flange and a locating
structure extending upwardly from the top flange; and a ladder
including a pair of spaced apart side plates and a bottom plate
defining a channel for conveying water in a flow direction, the
ladder including a plurality of generally planar baffles extending
between the side plates generally transverse to the flow direction,
the baffles being disposed such that the plane of the baffles is
angled relative to the bottom plate and a top edge of each baffle
is disposed closer to the structure interface than a bottom edge of
the baffle, the ladder operably coupled to the interface structure
with a detachable hinged connection.
18. The fish ladder of claim 17, wherein the baffles are angled at
about 45 degrees relative to the bottom plate.
19. The fish ladder of claim 17, wherein the detachable hinged
connection comprises a pair of spaced apart hinge pin receivers on
the structure interface, each hinge pin receiver defining a bore, a
pin receiving sleeve on the ladder, the pin receiving sleeve
defining a bore, and a hinge pin received through the bores of the
hinge pin receivers and the bore of the pin receiving sleeve.
20. The fish ladder of claim 19, wherein the ladder is shiftable
about the hinge pin between a first position in which the ladder
extends in a horizontal orientation from the structure interface
and a second sloped orientation in which the ladder slopes
downwardly from the structure interface.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to fisheries management tools,
and more specifically to fish ladders.
BACKGROUND OF THE INVENTION
[0002] Obstructions to natural water flow, caused for example by
roads, can fragment aquatic ecosystems and thereby affect fish
populations. Typically, culverts are installed under road grades to
facilitate passage of water, but such culverts often form
waterfalls at the drainage end due to the change in elevation, and
hence may themselves form a barrier to fish passage upstream. Such
culvert road crossings can occur at least once every square mile in
the Great Plains.
[0003] Fish typically must move upstream during short periods of
the year for purposes of spawning. The obstacle to fish passage
presented by culverts can be a particular problem for small bodied
fishes, such as minnows, suckers, and darters, as they are unable
to navigate even the small waterfalls and current presented by
culvert outflows.
[0004] Fish ladders to assist fish in moving upstream in water
courses are known. For example, in the Pacific Northwest of the
U.S., fish ladders and fishways have long been deployed to enable
salmon to migrate around the large hydroelectric dams that have
been built in the major rivers in that area.
[0005] Different types of fish ladders have been developed in the
past. The pool-and-weir fishway is one of the oldest designs and is
typically used at large barriers. These structures present a set of
steps, with pools before each step. A drawback of pool-and-weir
designs, however, is that they are most suited to large-bodied
fishes having significant jumping ability and are much less
effective in promoting movement of small-bodies fishes and fish
species.
[0006] "Denil" type fish ladders incorporate a ramp approach with
roughing features to simulate natural rapids. Baffles catch water
and turn it back on itself to create areas of low velocity,
enabling fish to ascend the ladder against the current. Denil type
fish ladders are generally more effective in promoting movement of
small-bodied fishes. A drawback of Denil type and other prior fish
ladder designs, however, is that they are typically permanent
structures. Placing permanent fish ladders or fishways at every
location where they would be desirable to promote optimal fish
management is prohibitively expensive, and also wasteful, in that
the ladders are only needed for a short period of time to enable
migration of fish, and otherwise are unnecessary. Further, these
structures can take weeks or months to plan and install. Still
further, such permanent structures can cause unintended and
undesirable alterations to the water course, such as silting, or
scour patterns in the downstream pool.
[0007] What is needed is an effective fish ladder structure for
small-bodied fishes that is easily portable so as to enable
installation and use in a given water course when needed, and
relocation at other times.
SUMMARY OF THE INVENTION
[0008] Embodiments of the present invention address the need for an
effective fish ladder structure for small-bodied fishes that is
easily portable so as to enable installation and use in a given
water course when needed, and relocation at other times. According
to embodiments, a fish ladder defines a channel with generally
evenly spaced baffles in the channel disposed at about 45.degree.
angles to the channel bottom. The ladder includes a bracket that
enables the ladder to be attached to any size, shape, and material
of culvert or other drainage structure. The ladder can be attached
to the bracket with a hinge mechanism, so as to accommodate
virtually any height of drop presented by small drainage
structures. With extendable legs, a fish ladder according to
embodiments of the invention is able to be installed in streams up
to 6 feet deep. The ladder can be scaled so as to target passage of
small-bodied non-game species such as minnows, while also passing
larger game species as well.
[0009] Embodiments of the present invention provide a fish ladder
that is modular, relatively small, able to be transported with a
light truck, and installed by one or two people in 1 to 4 hours.
Fisheries managers can easily install the ladder to target a
species of fish when they are migrating, and then move the ladder
to target other species in other areas during different times in
the year. With a funnel trap on the outlet of the ladder, it can be
used as a research tool as well. Taking little effort or resources
to install, along with the ability to attach to all material, size,
and shapes of drainage structures, embodiments of the invention
give fisheries managers a tool to improve stream connectivity
without the cost and effort associated with traditional fish
ladders or with replacing existing drainage structures.
[0010] According to an embodiment, a fish ladder includes a
structure interface adapted to attach to a drainage structure, the
structure interface portion including a weir plate, and a ladder
defining a channel for conveying water in a flow direction, the
ladder including a plurality of baffles disposed across the channel
generally transverse to the flow direction, the ladder operably
coupled to the interface structure with a detachable hinged
connection. The detachable hinged connection can include at least
one hinge pin receiver on the structure interface, the at least one
hinge pin receiver defining a first bore, a pin receiving sleeve on
the ladder, the pin receiving sleeve defining a second bore, and a
hinge pin received through the first bore and the second bore. The
ladder is shiftable about the hinge pin between a first position in
which the ladder extends in a horizontal orientation from the
structure interface and a second sloped orientation in which the
ladder slopes downwardly from the structure interface. The channel
can be defined by a pair of spaced apart substantially parallel
side panels and a bottom panel extending between the side
panels.
[0011] In embodiments, the baffles are angled rearwardly toward the
structure interface, and may be angled at about 45 degrees relative
to a bottom of the channel. In embodiments, the ladder can include
at least one support leg adapted to attach to the ladder. The
length of the support leg may be adjustable.
[0012] In an embodiment, a system for enabling fish migration
includes a drainage structure, and a fish ladder operably couplable
to the drainage structure. The fish ladder includes a structure
interface with a weir plate adapted to attach to the drainage
structure, and a ladder defining a channel for conveying water in a
flow direction. The ladder includes a plurality of baffles disposed
across the channel generally transverse to the flow direction. The
ladder is operably coupled to the interface structure with a
detachable hinged connection. In an embodiment, the detachable
hinged connection can include at least one hinge pin receiver on
the structure interface, the at least one hinge pin receiver
defining a first bore, a pin receiving sleeve on the ladder, the
pin receiving sleeve defining a second bore, and a hinge pin
received through the first bore and the second bore. The ladder may
be shiftable about the hinge pin between a first position in which
the ladder extends in a horizontal orientation from the structure
interface and a second sloped orientation in which the ladder
slopes downwardly from the structure interface.
[0013] In embodiments, the channel may be defined by a pair of
spaced apart substantially parallel side panels and a bottom panel
extending between the side panels. The baffles may be angled
rearwardly toward the structure interface at about 45 degrees
relative to a bottom of the channel.
[0014] In embodiments, the system can include at least one support
leg adapted to attach to the ladder. A length of the support leg
may be adjustable.
[0015] In an embodiment, a fish ladder can include a structure
interface adapted to attach to a drainage structure, the structure
interface portion including a weir plate presenting a top flange
and a locating structure extending upwardly from the top flange.
The fish ladder further includes a ladder with a pair of spaced
apart side plates and a bottom plate defining a channel for
conveying water in a flow direction, the ladder including a
plurality of generally planar baffles extending between the side
plates generally transverse to the flow direction, the baffles
being disposed such that the plane of the baffles is angled
relative to the bottom plate and a top edge of each baffle is
disposed closer to the structure interface than a bottom edge of
the baffle. The ladder is operably coupled to the interface
structure with a detachable hinged connection. The baffles may be
angled at about 45 degrees relative to the bottom plate.
[0016] In an embodiment, the detachable hinged connection includes
a pair of spaced apart hinge pin receivers on the structure
interface, each hinge pin receiver defining a bore, a pin receiving
sleeve on the ladder, the pin receiving sleeve defining a bore, and
a hinge pin received through the bores of the hinge pin receivers
and the bore of the pin receiving sleeve. The ladder can be
shiftable about the hinge pin between a first position in which the
ladder extends in a horizontal orientation from the structure
interface and a second sloped orientation in which the ladder
slopes downwardly from the structure interface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The embodiments of the present invention may be more
completely understood in consideration of the following detailed
description of various embodiments in connection with the
accompanying drawings, in which:
[0018] FIG. 1 depicts a fish ladder according to an embodiment of
the invention attached to a culvert and in use;
[0019] FIG. 2 is an isometric view of the fish ladder depicted in
FIG. 1;
[0020] FIG. 3 is a top view of the fish ladder of FIG. 2;
[0021] FIG. 4 is a cross-sectional view of the fish ladder of FIG.
2 taken at section 4-4 of FIG. 3;
[0022] FIG. 5 is a side elevation view of the fish ladder of FIG. 2
with the ladder in a horizontal position;
[0023] FIG. 6 is a front elevation view of the fish ladder of FIG.
2 with the ladder positioned in a downwardly sloped
orientation;
[0024] FIG. 7 is an isometric view of the drainage structure
interface portion of the fish ladder of FIG. 2;
[0025] FIG. 8 is an isometric view of the ladder portion of the
fish ladder of FIG. 2;
[0026] FIG. 9 is a side elevation view of the fish ladder of FIG. 2
with an extendable leg attached to the lower end of the ladder;
[0027] FIG. 10 is an elevation view of the drainage structure
interface portion of a fish ladder according to an embodiment of
the invention attached to a culvert;
[0028] FIG. 11 is a top plan view of the drainage structure
interface portion of a fish ladder according to an embodiment of
the invention attached to a culvert;
[0029] FIG. 12 is a side isometric view of the fish ladder of FIG.
1 during installation; and
[0030] FIG. 13 depicts an isometric view of the fish ladder of FIG.
1 with a funnel trap attached according to an embodiment of the
invention.
[0031] While the present invention is amenable to various
modifications and alternative forms, specifics thereof have been
shown by way of example in the drawings and will be described in
detail. It should be understood, however, that the intention is not
to limit the present invention to the particular embodiments
described. On the contrary, the intention is to cover all
modifications, equivalents, and alternatives falling within the
spirit and scope of the present invention.
DETAILED DESCRIPTION OF THE DRAWINGS
[0032] There is depicted in FIGS. 1-13 a small stream fish ladder
20 according to an embodiment of the invention. Fish ladder 20
generally includes drainage structure interface 22 and ladder 24.
Drainage structure interface 22 generally includes weir plate 26,
top flange 28, locating structure 30, and hinge pin receivers 32,
34. Locating structure 30 projects upwardly from top flange 28 and
includes side members 36, 38, and top member 40. Hinge pin
receivers 32, 34, are spaced apart on top flange 28 along front
edge 42, and each define a bore 44.
[0033] Ladder 24 generally includes spaced apart side panels 46,
48, bottom panel 50, baffles 52, pin receiving sleeve 54, and hinge
pin 56. Side panels 46, 48, are disposed parallel to each other,
and with bottom panel 50, define channel 58. Baffles 52 extend
between side panels 46, 48, and are disposed at about a 45 degree
angle relative to bottom panel 50, with the top edge 60 of each
baffle 52 angled toward proximal end 62 of ladder 24, and against
the direction of water flow WF as depicted in FIG. 4. Each side
panel 46, 48, is generally trapezoidal with angled distal end 64.
Proximal end 62 defines notch 66, with angled portion 68 extending
from notch 66 to bottom edge 70. Pin receiving sleeve 54 defines
bore 71, and is disposed at corner 72 of notch 66 and extends
between side panels 46, 48.
[0034] As depicted in FIGS. 1 and 10-12, ladder 20 is installed at
the drainage end of a culvert 74 by first attaching drainage
structure interface 22 so that weir plate 26 extends across the
bottom edge of culvert 74, forming a dam. Angle brackets 76 may be
used to attach weir plate 26 with lag bolts 78 screwed into culvert
74, and bolts 80 through weir plate 26. It will be readily
appreciated that structure interface may be attached to culvert 74
by any other suitable method including locking mechanisms, latches,
or other mechanical fasteners. In addition, although culvert 74 is
depicted herein as a cylindrical corrugated steel structure,
culvert 74 may be any other structure such as is commonly used for
providing drainage, for example, a concrete box culvert.
[0035] With structure interface 22 in place as depicted in FIG. 10,
water will be impounded behind weir plate 26, and will eventually
overtop top flange 28 as depicted in FIG. 1. Ladder 24 is attached
to structure interface 22 by registering bore 71 of pin receiving
sleeve 54 with bores 44 of hinge pin receivers 32, 34, positioning
side panel ends 82, 84, abutting the outer surfaces of side members
36, 38, respectively, of locating structure 30, and inserting hinge
pin 56 through bores 44 and bore 71 as depicted in FIG. 12. From
the horizontal position as depicted in FIG. 12, ladder 24 can then
be pivoted about hinge pin 56 until lower edge 86 of bottom plate
50 rests on the bottom of the water course as depicted in FIG. 1,
or until angled portion 68 abuts weir plate 26 as depicting in FIG.
9. If lower edge 86 is still above the water course bottom 88, one
or more leg assemblies 90 can be attached to ladder 24 for support
as depicted in FIG. 9. Leg assemblies 90 may include ladder
interface 92, shaft portion 94, and bottom plate 96. It will be
appreciated that shaft portion 94 may be telescoping so as to
enable different lengths for leg assembly 90, and ladder interface
92 may be a suitable mechanism so as to enable easy attachment and
detachment of shaft portion 94 from ladder interface 92. With
ladder 24 angled downwardly from structure interface 22, water
overtopping top flange 28 will flow down ladder 24, with areas of
low velocity in pockets 98 between baffles 52, enabling fish to
ascend ladder 24 against the direction of water flow WF.
[0036] It will be appreciated that fish ladder 20 may be made with
any desired dimensions while remaining within the scope of the
invention. In a particular embodiment, ladder 24 may be made with a
length L of about 80 inches, a width W of about 18 inches, a depth
D of about 141/2 inches, a baffle height D1 of about 7.8 inches,
and a baffle spacing of about 53/4 inches. These dimensions are
effective for promoting fish management, and also enable the ladder
20 to fit easily into the bed of a light truck for
transportation.
[0037] FIG. 13 depicts a fish ladder according to embodiments of
the invention with funnel trap 100 coupled to locating loop 30.
Funnel trap 100 may be any such structure as generally known in the
art, and includes wire mesh sides 102, 104, 106, 108, wire mesh end
110, and wire mesh funnel 112 with loop 114 defining opening 116.
Fish exiting from ladder 24 will exit through opening 116, and will
become trapped in funnel trap 100, thereby enabling their numbers
to be counted for research purposes.
[0038] The foregoing descriptions present numerous specific details
that provide a thorough understanding of various embodiments of the
invention. It will be apparent to one skilled in the art that
various embodiments, having been disclosed herein, may be practiced
without some or all of these specific details. In other instances,
components as are known to those of ordinary skill in the art have
not been described in detail herein in order to avoid unnecessarily
obscuring the present invention. It is to be understood that even
though numerous characteristics and advantages of various
embodiments are set forth in the foregoing description, together
with details of the structure and function of various embodiments,
this disclosure is illustrative only. Other embodiments may be
constructed that nevertheless employ the principles and spirit of
the present invention. Accordingly, this application is intended to
cover any adaptations or variations of the invention.
[0039] For purposes of interpreting the claims for the present
invention, it is expressly intended that the provisions of 35
U.S.C. .sctn.112(f) are not to be invoked unless the specific terms
"means for" or "step for" are recited in a claim.
* * * * *