Riparian Restoration
APPENDIXES
Appendix C: Waterjet Stinger
Riparian/Wetland Project Information Series No. 17
June 2001
Waterjet Stinger:
A tool to plant dormant unrooted cuttings of willows, cottonwoods, dogwoods,
and other species
J. Chris Hoag, Wetland Plant Ecologist
Boyd Simonson, Biological
Technician
Brent Cornforth, Biological Technician
Loren St. John, PMC Team
Leader. U.S. Department of Agriculture, Natural Resources Conservation Service,
Plant Materials Center, Aberdeen, ID 83210
[Used with permission.]
Introduction
Opportunities for riparian revegetation around the nation are numerous. Planting dormant unrooted cuttings often called pole plantings, post plantings, or live stakes is one technique that is often recommended for streambank stabilization and riparian buffer planting. This method is limited to species that can easily sprout from hardwood cuttings, such as: willows, cottonwoods, and dogwoods. There are other species that will sprout from hardwood cuttings, but do not root as readily. [See figure C1.]
Dormant unrooted cuttings are used because they are easy to harvest, easy to plant, inexpensive, and effective. In the arid and semi-arid West, it is extremely important that any plant that is installed in a riparian zone have its roots in the lowest watertable [sic] of the year. This is often difficult when using bareroot [sic] or containerized plants especially when the riparian zone has been dewatered to the point that the water table may be several feet below the soil surface. Unrooted cuttings have been planted as deep 12 ft (average depth is about 5-6 ft) by the Riparian/ Wetland Plant Development Project at the Aberdeen PMC using a long bar attached to a backhoe (Hoag and Ogle 1994). Most riparian and stream protection projects require planting depths of 3-6 ft. The biggest problem we faced was finding a method and developing equipment that could dig a hole more than 3-4 ft deep quickly and efficiently. The Waterjet Stinger is the result of this equipment development effort.
To plant unrooted cuttings successfully, the bottom of the cutting should be placed about 8-12 in into the lowest watertable [sic] of the year. The top of the cutting should extend out of the ground at least 10-12 in or high enough to be out of the shade cast by surrounding vegetation such as grasses or forbs. This allows the bottom of the cutting to act like a straw and pull water up the cutting keeping the roots, stems and leaves hydrated. In some riparian zones, the lowest water table of the year can be several feet deep.
Waterjet Stinger
The Waterjet Stinger [figure C2] was specially designed to use high-pressure water to hydrodrill a hole in the ground to plant unrooted hardwood cuttings into riparian revegetation. This is not new technology, in fact, it has been around for a long time. Oldham (1989) described a water drill that he used to drill holes in the ground to plant stem and pole cuttings 4-5 ft deep. His hydrodriller was a steel pipe that was beveled at the bottom and was hooked up to a “water tank (spray rig) or portable pump.” Drake and Langel (1998) reported using a water jet tool to plant willow cuttings. They designed a nozzle that is made out of stainless steel welded to a steel pipe. They used a high-pressure pump and the nozzles to plant cuttings over 2 meters deep. An engineering technician in Manitoba, Canada (Andrews, personal communication) described working with a water jet to drill holes for geotechnical test holes ten years ago. He indicated that they had taken a steel pipe and pounded the end flat to increase the water pressure. These earlier jets did not last very long because the pounding tended to weaken the steel.
The advantages of using the waterjet stinger to drill a hole for planting unrooted willow and cottonwood cuttings are: [figure C3]
- simple to operate
and transport
- little training necessary to operate
- hydrodrilling the
planting hole is fast
- plant large number of cuttings in a short
period of time
- allows cutting to be planted directly into a wet environment
- allows
for saturated soil conditions to surround the cutting for a longer
period
of time
- liquefied soil will settle around the cutting eliminating air pockets in the rooting zone [sic]
Based on a request from Scott Henderson, an Idaho NRCS Field Office employee, and others, Boyd Simonson, PMC Biological Technician, used the paper written by Drake and Langel (1998) and attempted to modify their design to better fit the coarse soils in the Intermountain West. He started with the actual probe itself. A local machinist used the detailed drawing to build the nozzle out of stainless steel and welded it to a 2 in steel pipe. Boyd added a T-handle at the top to help with the planting operation and a ball valve at the handle to turn the water on and off (see appendix A). [See figure C4.]
Figure C4—Handle with ball valve.
After testing in the field, we decided to add a set of vanes to be [sic] bottom on one of the probes. Three vanes were welded to the probe pipe directly above the stainless steel tip. The individual vanes were about four inches long, tapering down to the nozzle, and about 5/8 inch tall. The vanes provide several benefits. They open the hole up all the way down to accept wider diameter cuttings. This is especially true in compacted layers like clay. They also allow the user to nudge rocks slightly out the way in the hole. With the smooth pipe, it is almost impossible to get any leverage on rocks. For silt soils, the vanes are a real help. With cobbly soils, it does not provide a major advantage. We work in a combination of silts and gravels so we put vanes on one probe and left the other without vanes. [See figure C5.]
It took quite a bit of research to come up with the right size pump. Drake and Langel (1998) describe a “cube” pump, but we had difficulty finding anything with that name. We determined that the basic specifications for the pump were:
- gasoline powered
- small enough to fit on the back of an ATV
- output
of at least 80 psi or higher
- 120 gallons/minute output
- vertical lift of at least 18 ft
There are many different pumps that meet these specifications available on the market.
We did try a 1,600-psi pressure washer thinking that it was ready made for this type of application. The main problem is that pressure washers do not put out enough water volume for this application. The pressure washers typically put out about 2-3 gpm while the high-pressure pump puts out 120 gpm (about 12-15 gpm at the nozzle). Pressure washers have more than enough water pressure, but they tend to blow all the soil out of the hole for the first couple of inches making it pretty messy. After the hole is drilled, there is very little water left in the hole to hydrate the willow cuttings. We do not recommend using a pressure washer for this application.
Next, Boyd felt that for safety’s sake, a pressure relief valve should be installed so when both waterjets were shut off, the water from the pump would bypass back into the stream or other water source. This would decrease the pressure on the pump and eliminate turning the pump on and off. A manifold was designed to fit on the pump to allow the water to flow from the stream to either the waterjet stingers or to the bypass hose. When a certain internal pressure is reached inside the manifold, the water will divert to the bypass hose and back into the stream automatically. An additional benefit to the pressure relief valve was that it allows one to release air out of the system. This made the priming go much faster.
The garden hose quick coupler manifold allows two waterjets to run simultaneously. [See figure C6.] It is attached to the main manifold just past the pressure relief valve. Quick couple attachments (available at most lawn and garden stores) are used to keep the connections simple, reduce the possibility of stripping the treads on the hose ends, and to allow the hoses to be hooked up in either direction. Water is delivered through heavy-duty s in garden hoses with a pressure rating of 100 psi that are 100 ft long. The hoses run from the garden hose quick couple manifold to the waterjets.
Figure C6— Garden hose quick coupler manifold.
At the planting site, the hoses are laid out parallel to the stream channel. The two waterjets can be operated with two separate crews. One crewmember runs each waterjet and the other crewmembers transport the cuttings and push them into the holes after they are hydrodrilled. As the holes are hydrodrilled and planted in the 200 ft length, the ATV with the waterjet stinger pump is driven further down the streambank and the process starts all over again. If the streambank is too high and the lift is too great to get water from the stream to the pump, the pump can be dismounted from the ATV and placed on a flat shelf that is cut right into the streambank. This way the pump is placed closer to the water, lift is reduced, and pressure increased at the nozzles.
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