Hydroseed Challenges, Hydroseed Solutions
Difficult terrain calls for a creative approach.
There are slopes and then there are slopes.
Some of the slopes on the back sides of the dams around Horsetooth
Reservoir in Colorado, for example, reached 1:1 and stretched as much as
800 to 1,000 feet long. The hydroseeding equipment used on the
reclamation project was pulled up and supported on its way down by
tractors on narrow roads constructed especially for the job.
On the other hand, the Ruby Natural Gas Pipeline reclamation project
involved working on terrains that ranged from wetlands to steep
mountains, in multiple states, with multiple contractors, private
landowners, and federal agencies.
The Garden State Parkway Expansion in New Jersey posed logistical
problems such as setting up the staging area in a different but always
confined location every day and meeting a strict deadline in spite of
being shut down when it rained and when traffic was too heavy.
Other challenges hydroseeding companies face are tree trunks and
boulders, erratic winds, and lack of access, all of which make it
difficult to spray seed and mulch evenly.
Whatever the challenges and the limitations, though, there’s a mulch,
a seed mix, and an application technique to overcome them, as the
following projects show.
Horsetooth Reservoir stretches 6.5 miles through a narrow valley in the
foothills just 5 miles west of Fort Collins, CO. While it supplies water
for drinking, irrigation, hydropower generation, and recreation, for
years it also posed hidden dangers. According to the US Bureau of
Reclamation (USBR), seepage was increasing under one of its 50-year-old
earthfill dams, and all four of its dams were susceptible to earthquake
damage. Tens of thousands of people live downstream.
Spraying HydroStraw Guar Plus on a flatter section of the Garden State Parkway
The Modernization of the Dam project, which took more than two and a
half years, was completed in 2003. Horsetooth Dam, to the north, was
repaired; the downstream faces of the three dams to the east, Soldier
Canyon, Dixon Canyon, and Spring Canyon dams, were stabilized; and all
four dams were made earthquake safe.
In 2004, Rocky Mountain Reclamation (RMR), in Laramie, WY, stepped in
to reclaim the backsides of the three dams to the east. During the
modernization project, equipment had pushed soil from the tops of the
dams down the backsides, where it had either settled in an angle of
repose or been graded to different slope gradients, says Ron Schreibeis,
president and co-owner with his wife, Valerie, of RMR. The company
provides consulting services relating to revegetation and reclamation
and is also a reclamation construction contractor.
“This was a fairly complex project with quite a variety of revegetation techniques,” Schreibeis says.
Because soil settles at different angles, depending on the type of
soil, and because grading requirements varied depending on site design
criteria, these slopes ranged from 1:1 to 3:1 or flatter, and they were
very prone to erosion. RMR used a number of seed varieties, mulches, and
application techniques to protect them, including seed, virgin aspen
wood fiber mulch, and Biosol, an organic soil amendment, from Granite
Seed in Lehi, UT.
Horsetooth Reservoir is part of the Colorado-Big Thompson project,
which is designed to collect water from the headwaters of the Colorado
River and divert it from Colorado’s West Slope to its Front Range and
plains. It’s owned by USBR and has an elevation of 5,430 feet and a
total capacity of about 151,750 acre-feet.
The long, narrow reservoir runs north-south and is bounded by
mountains on the south and the west, Horsetooth Dam on the north, and
the Dakota Hogback, a long ridge at the edge of the Rocky Mountains, on
the east. Soldier, Dixon, and Spring canyons cut through the hogback.
They were dammed up in the mid- to late-1940s when the reservoir was
built. They’re between 155 and 240 feet high and contain more than 10
million cubic yards of earthfill. The project reclaimed just under 100
The first challenge was the logistics. “At three different points,
three streams had broken through along the hogback and formed three
valleys,” Schreibeis says. “We worked in three locations with three
different access points, three sources of water, and three areas to
store our materials.”
While the flatter slopes had been graded with dozers, a major
challenge was getting the 65,000-pound hydroseeding machines up and down
the steepest slopes, many of them 800 to 1,000 feet long.
Because the slopes were so steep and long, the contractor had built
roads to get the equipment up, and because the roads had to be built
fairly level from side to side, they were narrow. RMR hooked the
machines to tractors with a tow cable to pull them up and to control
their speed on the way down—dangerous work. “We went through all the
procedures with the safety department,” he says.
The company used seed, mulch, and techniques that were specified by USBR engineers.
“Normally we make recommendations for modifications,” Schreibeis says.
“Specs are often boilerplated because engineers often don’t have the
time or resources to research a project like this. But most of the
recommendations and procedures were already done.”
Workers applied several different mixes of cool- and warm-season
native dryland grasses, depending on the slope. All were from Granite
Seed, which carries a wide variety of seed and erosion control products.
“We work with Granite Seed often,” he says. “Generally, for most of
our situations, they are the best. Few other companies can compete with
their quality and service. They generally have a good inventory even of
the more specialized species we require.”
Straw mulching in Scare Canyon, UT
Some of the seed was specifically for wildlife habitat. “We want
wildlife to utilize and graze revegetated areas. If they don’t, and if
livestock don’t have access, there’s often a long-term decrease in the
quality and condition of the vegetation. For most rangeland in the West,
controlled grazing is a good thing for the land.”
On the flatter land, crews generally drill-seeded tame pasture seed
mixtures, and then mulched with certified noxious-weed-free grass hay
mulch. They crimped in the mulch with specially designed,
RMR-constructed mulch crimpers.
On the steeper slopes they primarily applied 100% virgin aspen wood
fiber mulch from Granite Seed. According to Granite Seed, the thermally
refined wood fibers have up to 50% more water-holding capacity than
atmospherically refined wood mulch, which allows them to absorb water
Applying the mulch evenly around the boulders, some of which reached
the size of small pickups, was another challenge. “The contractors had
built the minimum possible number of roads, so our operators didn’t have
good access,” Schreibeis says. “Once they were on the slopes, the main
challenge was for them to make sure the mulch covered the seed.”
Crews used the winds, working in one area and then when the winds
changed, going to another spot. They tried to cover the seed as quickly
as possible with at least three coats of hydromulch to protect it from
rodents and birds, sun, and wind and water erosional forces, but during
this project the wind could change before they finished. They would
either try to get at least a couple of loads on before it changed, or
wait until it changed back.
On the steepest, most difficult slopes the crews applied a bonded fiber
matrix mulch and Biosol. According to Granite Seed, Biosol was developed
in the same way as slow-release vitamins; it won’t burn seed or
existing vegetation and it doesn’t require watering immediately after
“Biosol provides macronutrients, organics, and other desirable
components for enhancing revegetation establishment,” Schreibeis says.
When the hydromulching was finished, the roads up the slopes had to
be obliterated, and going down was sometimes more frightening than going
“Because the roads were narrow, an excavator would get up the road
ahead of us and wipe out 30 to 40 yards of road at a time,” Schreibeis
says. “Then he’d ease himself off the road, and we’d back up and spray
it out, then pull down the road out of his way and hold ourselves on the
slope while he’d pull back on the road and wipe out another 30 to 40
yards. It took good operators to do that, and there were a number of
potential hazards and dangerous situations that we addressed before and
during this procedure to assure safe working conditions for our people.”
It was a very slow, tedious process, he says, “but it was one of
those costly things that there was no way around. According to the
contractor and what we’ve learned from the city, the project went
wonderfully and is a success.”
Ruby Natural Gas Pipeline
The Ruby Natural Gas Pipeline snakes through four states, from the
southwest corner of Wyoming to southern Oregon, through terrain that
ranges from wetlands to desert to some of the steepest mountains in the
country, and through farmland and public land regulated by multiple
federal agencies including the Bureau of Land Management, the Forest
Service, and the Federal Energy Regulatory Commission.
Arnold’s Custom Seeding (ACS), in Keenesburg, CO, reclaimed 558 of
the nearly 680 miles of the pipeline, through the heat of the summer and
the snow, ice, and darkness of the winter. The company, which
specializes in reclamation, forest restoration, and erosion control,
used a wide variety of seeding and mulching techniques.
“It depended on what each district wanted and the angle of the
slope,” says Corey Huwa, who runs the family-owned company with his
brother, Brent. One product the company used is the relatively new
WoodStraw, an erosion control mulch by Forest Concepts in Auburn, WA.
It’s a blend of loose, long, thin wood pieces, almost like writing
pencils, Huwa says, that was applied from the ground and the air. They
also used straw mulch, Terra-Matrix SMM (Stabilized Mulch Matrix),
Flexterra HP-FGM (High Performance Flexible Growth Medium), and
Ecology and Environment Inc. (E and E) of Lancaster, NY, did the
environmental studies before El Paso Corp.’s 42-inch underground
pipeline, which delivers natural gas to California, Nevada, and the
Pacific Northwest, was built. A number of companies carried out the
“When they do the pipeline, they clear the vegetation and push the
topsoil to one side of the right of way,” Huwa says. Crews place the
fill on the opposite side. Once the pipeline is in, the contractors
replace everything, including rocks, as closely as possible to where
they found them.
ACS started work in October 2010 and finished mulching in September 2011. Another company is transplanting seedlings.
ACS applied Flexterra HP-FGM on the steepest slopes with the most highly erodible soils.
Brent Huwa, along with employees Matt Dorenkamp and James Simpson,
managed the eastern side of the approximately 8,500-acre project. Corey
Huwa, with employees Shawn Hesse and Brice Larrick, handled the western
two-thirds. The temporary easements along the 558 miles varied from the
nominal width of 115 feet to as wide as 195 feet on steep slopes and as
narrow as 75 feet near wetlands, archeological sites, and other areas of
On BLM land, much of which is leased to ranchers for pasture, ACS
replaced everything as closely as possible to the locations E and E had
found them. “BLM districts like the right of way to be in a roughened
state,” Huwa says. “It can help catch some water, protect delicate
sprouts from the wind, and create a mini-geological climatic growing
On land that wasn’t rocky, ACS tilled to relieve the soil compaction.
E and E had identified the soils, and had found that on much of the
land they were good and fertile. ACS treated poor soils with its
proprietary blend of soil amendments. On cryptobiotic soils, where
organisms had stopped growing because of the adverse environmental
conditions, ACS added mycorrhizal inoculum (AM 120) from Granite Seed in
ACS seeded with seed mixes that E and E had prescribed. On federal
land, they planted almost all native seed. On BLM land that was leased
to ranchers for pasture they planted grass. On private land they planted
according to landowner requests. “Most of the seed came from Sharp
Brothers in Greeley,” Huwa says. “We use them a lot.”
Crews drill-seeded most of the job. If the conditions were unsafe for
the equipment, they broadcast seeded and harrowed, and if the
conditions were unsafe for broadcasting from the ground, they broadcast
by air. They also used broadcast seeding for species that must be placed
on the surface in order to germinate, such as sagebrush, forage kochia,
The mulch and the application depended on the degree of the slope and
the landowners and agencies in charge. Most of the time, Huwa made
recommendations that were approved on a case-by-case basis. The BLM
districts in Nevada, however, specified WoodStraw by Forest Concepts,
because they wanted to ensure that the mulch wouldn’t contain any weeds.
According to Forest Concepts, each piece in the mulch has a high
length-to-width ratio, so the pieces, mostly Douglas fir, hemlock, and
other conifer species, form a protective matrix when they’re distributed
on the soil. WoodStraw can be spread by hand, straw blower, or
helicopter, is naturally weed free, provides shade for seeds, and
doesn’t get displaced by wind, even on steep slopes. It does not need to
be crimped into the soil.
WoodStraw lasts four years or more.
ACS applied several truckloads both from the ground and by air. “We have
seen some light reeling under the product,” Huwa says, “but this method
can be less expensive than hydromulch or erosion control blanket for
slopes where water erosion is not a concern.”
The Wyoming section was fairly flat, he says, which allowed the
company to apply certified weed-free straw with mechanical straw blowers
on the ground. Crews crimped the straw 3 or 4 inches into the soil to
hold it into the ground.
The Utah section, on the other hand, is very extreme, he says. “There
are areas with super-steep slopes and highly erosive soils. A lot of
that had to be done by helicopter.”
On the flatter areas, crews applied straw from the ground and crimped
it in. On the moderate slopes, they applied Terra-Matrix SMM from
Profile Products, also from the ground. It’s basically a mixture of wood
mulch and glue that goes on as a slurry and binds with the soil, Huwa
On the steepest slopes with highly erodible soil, they applied
Flexterra HP-FGM, also from Profile Products, from both the ground and
the air. “It’s basically a virgin wood mulch and a cross-linked
tackifier,” he says. “It’s more expensive up front, but it will protect
an extreme slope until vegetative growth is established.”
In Oregon the company aerially applied DustFloc, a soil binder made
of a blend of natural and organic polysaccharides, from Apex Resources
of Louisville, KY. It’s an inexpensive way to protect the soil from
water and wind erosion, but doesn’t provide shade for seeds.
So far, the soils have held very well, Huwa says, but he does expect
that some areas will have to be retreated within the next two or three
years. Rainfall mostly will help, since this is a very dry part of the
“We’ve had unbelievable vegetation success across Oregon and Nevada
due to careful product selection, good seed, specialized installation
and application methods, and an unusual amount of precipitation during
the winter months. We’ve had great success across Utah and Wyoming as
well.Our goal is for the right-of-way scar to disappear within five to
seven years,” he says.
“It’s nice to work with a gas company like El Paso that genuinely
cares about doing the job right the first time and doesn’t ask us to
take any shortcuts. This attitude ensures protection of wildlife, water,
and all of our natural resources.”
Garden State Parkway Expansion
Sometimes the slopes are the easy part.
The Garden State Parkway used to be known for traffic congestion to and
from the beaches and the casinos on the New Jersey shore. Thanks to a
road-widening project by the New Jersey Turnpike Authority, traffic is
running more smoothly now. The project expanded a 13-mile stretch of the
two-lane divided highway by adding a new slow lane in each direction as
well as widening the shoulders.
Once the expansion was completed, Hydrograss Technologies, which
specializes in engineered solutions in erosion and dust control as well
as stormwater management, took over.
“The tracked equipment used for large tree removal during the
road-widening process had disturbed and exposed soils, leaving them ripe
for erosion,” says Bob Arello, president of the company, which has
offices in Massachusetts and Florida. Hydrograss stabilized the median,
the easements, and the on and off ramps. The company used seed from
Summit Seed in Manteno, IL. On flat surfaces, crews applied the
hydromulch HydroStraw Guar Plus, also from Summit Seed, and GeoMatrix
SS, a soil-specific BFM from its own company, for the slopes.
The main challenges during this project had little to do with slopes.
Instead, they concerned logistics as well as limited time and space.
By the time work began in March 2011, some of the challenges had
already been solved. One was synchronizing the 18 shipments of
HydroStraw that came in by truck from Oregon.
“The holding yard was only so big,” Arello says. “Ron [Edwards, of
HydroStraw] helped a lot with organizing the freight liners and the
people involved in shipping. We’d get around three to four trucks a
week—22 tons of material a load.”
And then there was the logistics of hauling the water needed for the
hydroseeding and hydromulching. The job site was a couple of miles from
the ocean, and the other sources of water were anywhere from 14 to 26
miles away. Hydrograss used four 6,000-gallon water trucks to transport
water from the ocean into two 21,000-gallon frac tanks that were
positioned daily at strategic points to expedite the seeding operation.
Crews set up staging areas in highway turnarounds. It was faster, and
they had to be as efficient as possible because dictated labor rates
were well over $70 per hour for each man. Going back to the holding area
would have been too costly, Arello says. Because they were constantly
progressing up the road, every morning they moved all the equipment and
products to a new holding area for the work they were doing that day.
The highway was never closed while the crews worked. Instead, the
Turnpike Authority would close a section about 2 miles long of either a
northbound or southbound lane, and either the fast lane, so they could
spray the easements, or the slow lane, so they could spray the median.
When Hydrograss finished spraying, the Turnpike Authority would move up
another 2 miles and close that section, and the crew would repeat the
process, Arello says.
“If there was too much traffic, they shut us down.” At the same time,
he says, “it was mandatory that the work be accomplished before
Memorial Day, or liquidated damages would have been assessed to the
Hydrograss Technologies applied the seed and fertilizer first. One of
Summit Seed’s specialties is turf grass seed mixtures for
low-maintenance turf. This was a rye and fescue blend that was approved
by the Turnpike Authority. It was intended to last only a couple of
years, because additional bids for more construction and widening
projects were in the pipeline to take place the following season.
Workers covered the easements, which were between 60 to 150 feet wide
to the wood line, the shoulders, the median, and the on and off ramps.
Although the easements were flat, applying the seed and the mulch evenly
was tricky, too.
“The contractors had cut the trees as tight to the ground as possible
as per specifications,” Arello says. “They tried to get 1 to 2 inches
from the soil, but the ground was very undulating.”
The Turnpike Authority had specified blown hay as a cover material,
but it was impossible to reach the 150 feet from the guard rails to the
tree line with conventional hay-blowing machines, and there was no
vehicle access to most of the seeded areas. In addition, a constant
driving wind could have created severe dust and blown the hay onto the
highway instead of the target area, says Arello, who also does onsite
“We suggested to the contractor that we replace the blown straw with
HydroStraw Guar Plus, because the wet delivery system both prevents dust
and helps in the ease of application. We had the equipment to get the
job done. We drove two trucks down from the Northeast and one truck up
HydroStraw Guar Plus was applied on the 390 acres of flatter land—the
easements, the shoulders and the medians. According to HydroStraw, the
manufacturing process results in greater soil coverage and higher water
retention. The product was preblended to eliminate field mixing, with
processed straw fibers, a guar gum tackifier, and a high-strength
polymer binder to ensure smooth operation. It binds to the soil to
prevent erosion, protects seed, and helps it germinate. Hydrograss used
1,900 pounds per acre and covered 2 acres per load.
On the 44 acres of on and off ramps, which were 3:1 slopes or
greater, Hydrograss used its own GeoMatrix SS, which stabilizes severe
slopes, as the Turnpike Authority had specified. The company used one
Finn T-330, one Apex Extreme 4200, and one Apex Extreme 5,000-gallon
hydroseeding machine to complete the contract.
The project was finished right after Memorial Day. “Some days we
covered 30 acres with the trucks,” Arello says. “It was tough, but with
an experienced crew and some of the best equipment in the industry, we
accomplished the work.”
Author's Bio: Janet Aird is a California writer specializing in agricultural and landscaping topics.