HomeMy WebLinkAbout1.03 General Application Materials_PartDWeed Management Plan March 2021
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1.0 Summary
This Weed Management Plan was prepared at the request of IHC Scott (Scott) [formerly
Scott Contracting, Inc. (SCI)] to fulfill the submittal requirements of the Land Use and
Development Code (LUDC). Scott is proposing to develop an aggregate mine (gravel pit)
within the existing pastures. The proposed project is located in Garfield County, Colorado in
Sections 8 and 17, Township 6 South, Range 92 West (6th Principal Meridian) (Figure 1).
SGM was retained by Scott to conduct a noxious weed survey to fulfill requirements of
Garfield County’s LUDC and Vegetation Management department. A field survey
documenting and mapping noxious weeds was conducted on May 13th, 2020, by Eric
Petterson, Senior Ecologist.
Both Garfield County’s noxious weed list1 and the State of Colorado’s noxious weed list2
were utilized for survey efforts (Appendix A and B). To summarize, surveys found the
following State and Garfield County listed noxious weeds:
Table 1 – Noxious Weeds Present on Property
Noxious Weeds
Common Name Scientific Name Colorado Listed
Species
Garfield County
Listed Species
Bulbous bluegrass Poa bulbosa List C No
Bull thistle Cirsium vulgare List B Yes
Canada thistle Cirsium arvense List B Yes
Cheatgrass Anisantha (Bromus) tectorum List C No
Chicory Cichorium intybus List C Yes
Common reed Phragmites australis Watch list No
Hoary cress Lepidium draba List B Yes
Russian knapweed Acroptilon repens List B Yes
Russian olive Elaeagnus angustifoilia List B Yes
Salt cedar Tamarix sp. List B Yes
1 Garfield County Noxious Weed list: http://www.garfield-county.com/vegetation-management/noxious-weed-list.aspx
2 Colorado Noxious Weed list: http://www.colorado.gov/cs/Satellite?blobcol=urldata&blobheadername1=Content-
Disposition&blobheadername2=Content-Type&blobheadervalue1=inline%3B+filename%3D%22Noxious+Weed+List.pdf
%22&blobheadervalue2=application%2Fpdf&blobkey=id&blobtable=MungoBlobs&blobwhere=1251965326013&ssbina
ry=true
Weed Management Plan March 2021
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2.0 Description of Survey Area
Vegetation on the property is dominated by partially irrigated pasture lands, which are
subjected to an inconsistent and uneven application of irrigation water via flood irrigation
and subsurface seepage. Other community types on the property include sagebrush
shrublands (dominated by basin sagebrush (Artemisia tridentata sbsp. tridentata), areas of
greasewood shrublands (Sarcobatus vermiculatus), and expansive wetlands. The property
has a mixture of mesic and hydric soil conditions which supports a mosaic of upland pasture
areas and wet emergent meadows. The water table is so elevated in some portions that the
wet meadows contain areas of open surface water. Some small areas contain sparse
riparian woodland, dominated by Russian olive (Elaeagnus angustifolia) with a sparse
overstory of cottonwood (Populus deltoides).
Dominant vegetation species include the following:
Upland Pastures
· Alfalfa (Medicago sativa)
· Chicory (Cichorium intybus)
· Timothy grass (Phleum pratense)
· Showy milkweed (Asclepias speciosa)
· Tall wheatgrass (Thinopyrum ponticum)
· Hyprid western wheatgrass (Pascopyrum smithii hybrid)
· Russian knapweed (Acroptilon repens)
· Cheatgrass (Anisantha tectorum)
Herbaceous Emergent Wetlands
· Arctic rush (Juncus balticus)
· Showy milkweed (Asclepias speciosa)
· Alkali sacaton (Sporobolus airoides)
· Foxtail barley (Hordeum jubatum)
· Broadleaf cattail (Typha latifolia)
· Bulrush (Schoenoplectus maritimus)
· Tamarisk (Tamarix chinensis)
· Cheatgrass (Anisantha tectorum)
Weed Management Plan March 2021
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Upland meadow conditions
Sagebrush/greasewood communities
transitioning to wetlands (July 2019)
Cattle loafing areas underneath cottonwoods Greasewood community types
3.0 Results of Surveys
The most common noxious weeds found within the project area include Russian olive,
chicory, and Russian knapweed. Chicory was common across the entire property (aside
from wetlands), but at relatively low densities. Because of this, chicory was not mapped
(otherwise the occurrence map would cover most of the property).
Russian olive trees were also common across the property (see Figure 2. Russian Olive
Occurrences). Cheatgrass (Anisantha tectorum) was generally limited to the driest sites,
primarily at the northern end in sagebrush/greasewood community types; in these areas
cheatgrass infestations were widespread, but of very low density/coverages.
Figures 2 and 3 shows the areas of noxious weed infestations and relative densities. Other
species such as redstem filaree (Erodium cicutarium) and field bindweed (Convolvulus
arvensis) are likely to be present but were not observed during the May site visit.
Weed Management Plan March 2021 4Figure 1. Project Area Existing Conditions
Weed Management Plan March 2021 5Figure 2. Russian Olive Occurrences
Weed Management Plan March 2021 6Figure 3. Other Noxious Weed Occurrences
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4.0 Noxious Weed Management Recommendations
To meet the requirements of the Colorado Noxious Weed Act and Garfield County guidance,
Scott shall conduct prescribed management techniques for noxious weeds included on one
of three State weed lists: List A – designated for statewide eradication; List B – managed to
prevent further spread and, for selected species, designated for eradication in large areas;
and List C – of more localized concern, but for which the State will provide education,
research, and biological control assistance to jurisdictions that choose to manage the
species. The current State list is available in Appendix A.
In summary, weed control will be achieved by:
· A weed survey of the permit area will be completed every spring.
· Infestations will be treated using approved chemicals and will be sprayed by the
landowner or a certified applicator.
· After reclamation, weed surveys and treatment will continue until the perennial cover
and production of the site have met Division of Reclamation Mining and Safety
(DRMS) requirements and bond release has been obtained.
There are no List A species present in the project area. To stop the spread of List B species
(refer to Table 1), populations of every species designated for eradication shall be
eliminated prior to seed development.
Control of invasive species is a difficult task and requires on-going control measures. Care
must be taken to avoid negatively impacting desirable plant communities and inviting
infestation by other pioneer invaders. Weed management is best achieved by employing
aggressive control early on, and persistent control efforts over several growing seasons,
including direct treatments, prevention through best management practices, monitoring of
treatment efficacy, and subsequent detection efforts. Weed management is often limited to
controlling existing infestations and prevention of further infestations, rather than
eradication, but through effective weed management practices and eradication can be
possible in small to medium sized weed populations.
Scott will address the treatment of all noxious weeds on a biannual basis, with an herbicide
application in the spring (late May) and late summer (late August). Gravel storage piles will
also be treated with a bare ground herbicide if the piles are expected to remain for more
than one season. Scott will use a Colorado-certified herbicide applicator. All work
equipment will be sanitized and have any existing dirt, vegetation, or seeds from
landscaping and operational work removed before leaving the work area. Prior to bond
release, Scott will conduct a noxious weed inventory and bond release reports developed by
third parties for submittal to DRMS and Garfield County. The weed inventory will also
include a timetable for Russian-olive and tamarisk removal for non-reclaimed areas as part
of their Weed Management Plan, if needed.
Additionally, to meet reclamation objectives, Scott should eliminate or minimize those
noxious and invasive weeds designated as “undesirable species”. Undesirable species
include common reed (aka phragmites, a “watch list” species), redstem filaree, and all List C
species (e.g., cheatgrass), and invasive species that commonly colonize disturbed or
reclaimed land and impede or prevent establishment of desirable species (e.g., kochia
[Kochia sieversiana, K. iranica, K. scoparia] and Russian thistle [Salsola australis, S. iberica,
S. kali]).
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Preventive:
The first and the most important step in a weed control program and probably the most cost-
effective method of weed control is prevention. Methods include maintaining healthy
pastures, using weed-free crop seed, weed-free manure and hay, and clean equipment, as
well as the elimination of weed infestations in areas bordering cropland, and in irrigation
ditches and canals.
Scott will also practice proper equipment cleaning to minimize transport of noxious weeds,
dirt, vegetation, or seeds off-site.
Cultural:
Methods include: Establishing and managing an adequate population of desirable
vegetation to compete with the weeds; utilizing livestock (cattle, goats, sheep) when
possible; mulching; burning; and even plastic weed barriers.
Mechanical:
Methods include: Hand-pull, hoe, mow and tillage.
Biological:
Biological weed control involves the utilization of natural enemies for the control of specific
weed species. This method can take many years to result in weed control and is often not
100% effective. However, this method can dramatically help reduce weed densities and
when combined with other methods can be very beneficial. Methods include grazing,
introduction of registered insects or diseases. Contact the Palisade Insectary for more
information.
Herbicide application: It is extremely important to treat small infestation of certain weeds
(List A and B species to be eradicated) as soon as possible. Herbicides are most effective
when sprayed at specific stages during the life cycle of the weed. To ensure that small
infestations of noxious weeds are controlled or eradicated effectively, it is extremely
important to take immediate action on certain weed patches.
Treatment in the spring (late May) to catch biennial thistles, knapweed, and other species is
recommended. A follow up fall treatment (August) is further recommended.
Source Water Protection. A Source Water Protection Plan was developed in 2013 for
community drinking water systems in Garfield County. The property occurs within the City of
Rifle watershed. The plan prioritizes source water protection concerns and identifies local
source water management approaches that can be implemented to protect the source of
drinking water for these communities. It delineates areas around these communities as
source water protection areas. Pesticide application was identified a potential source of
water contamination. Application of herbicides should follow label directions and selective
spot spraying to ensure direct treatment of noxious weeds and protection of native
vegetation and water resources.
Weed Management Plan March 2021
Appendix A
Appendix A – State of Colorado Noxious Weeds
Colorado Noxious Weeds (including Watch List), effective June, 2020
List A Species (25)
Common Scientific
African rue (Peganum harmala)
Bohemian knotweed (Fallopia x bohemicum)
Camelthorn (Alhagi maurorum)
Common crupina (Crupina vulgaris)
Cypress spurge (Euphorbia cyparissias)
Dyer's woad (Isatis tinctoria)
Elongated mustard (Brassica elongata)
Flowering rush (Butomus umbellatus)
Giant knotweed (Fallopia sachalinensis)
Giant reed (Arundo donax)
Giant salvinia (Salvinia molesta)
Hairy willow-herb (Epilobium hirsutum)
Hydrilla (Hydrilla verticillata)
Japanese knotweed (Fallopia japonica)
Meadow knapweed (Centaurea x moncktonii)
Mediterranean sage (Salvia aethiopis)
Medusahead (Taeniatherum caput-medusae)
Myrtle spurge (Euphorbia myrsinites)
Orange hawkweed (Hieracium aurantiacum)
Parrotfeather (Myriophyllum aquaticum)
Purple loosestrife (Lythrum salicaria)
Rush skeletonweed (Chondrilla juncea)
Squarrose knapweed (Centaurea virgata)
Tansy ragwort (Senecio jacobaea)
Yellow starthistle (Centaurea solstitialis)
List B Species (38)
Common Scientific
Absinth wormwood (Artemisia absinthium)
Black henbane (Hyoscyamus niger)
Bouncingbet (Saponaria officinalis)
Bull thistle (Cirsium vulgare)
Canada thistle (Cirsium arvense)
Chinese clematis (Clematis orientalis)
Common tansy (Tanacetum vulgare)
Common teasel (Dipsacus fullonum)
Cutleaf teasel (Dipsacus laciniatus)
Dalmatian toadflax, broad-leaved (Linaria dalmatica)
Dalmatian toadflax, narrow-leaved (Linaria genistifolia)
Dame's rocket (Hesperis matronalis)
Diffuse knapweed (Centaurea diffusa)
Eurasian watermilfoil (Myriophyllum spicatum)
Hoary cress (Cardaria draba)
Houndstongue (Cynoglossum officinale)
Colorado Noxious Weeds (including Watch List), effective June, 2020
List B Species Continued (38)
Common Scientific
Jointed goatgrass (Aegilops cylindrica)
Leafy spurge (Euphorbia esula)
Mayweed chamomile (Anthemis cotula)
Moth mullein (Verbascum blattaria)
Musk thistle (Carduus nutans)
Oxeye daisy (Leucanthemum vulgare)
Perennial pepperweed (Lepidium latifolium)
Plumeless thistle (Carduus acanthoides)
Russian knapweed (Rhaponticum repens)
Russian-olive (Elaeagnus angustifolia)
Salt cedar (Tamarix. ramosissima)
Salt cedar (T. chinensis)
Scentless chamomile (Tripleurospermum inodorum)
Scotch thistle (Onopordum acanthium)
Scotch thistle (O. tauricum)
Spotted knapweed (Centaurea stoebe L. ssp. micranthos)
Spotted x diffuse knapweed hybrid (Centaurea x psammogena)
Sulfur cinquefoil (Potentilla recta)
Wild caraway (Carum carvi)
Yellow nutsedge (Cyperus esculentus)
Yellow toadflax (Linaria vulgaris)
Yellow x Dalmatian toadflax hybrid (Linaria vulgaris x L. dalmatica)
List C Species (16)
Common Scientific
Bulbous bluegrass (Poa bulbosa)
Chicory (Cichorium intybus)
Common burdock (Arctium minus)
Common mullein (Verbascum thapsus)
Common St. Johnswort (Hypericum perforatum)
Downy brome, cheatgrass (Bromus tectorum)
Field bindweed (Convolvulus arvensis)
Halogeton (Halogeton glomeratus)
Johnsongrass (Sorghum halepense)
Perennial sowthistle (Sonchus arvensis)
Poison hemlock (Conium maculatum)
Puncturevine (Tribulus terrestris)
Quackgrass (Elymus repens)
Redstem filaree (Erodium cicutarium)
Velvetleaf (Abutilon theophrasti)
Wild proso millet (Panicum miliaceum)
Colorado Noxious Weeds (including Watch List), effective June, 2020
Watch List Species (19)
Common Scientific
Baby's breath (Gypsophila paniculata)
Caucasian bluestem (Bothriochloa bladhii)
Common bugloss (Anchusa officinalis)
Common reed (Phragmites australis)
Garden loosestrife (Lysimachia vulgaris)
Garlic mustard (Alliaria petiolata)
Himalayan blackberry (Rubus armeniacus)
Hoary alyssum (Berteroa incana L.)
Meadow hawkweed (Hieracium caespitosum)
Onionweed (Asphodelus fistulosus)
Siberian elm (Ulmus pumila)
Scotch broom (Cytisus scoparius)
Swainsonpea (Sphaerophysa salsula)
Syrian beancaper (Zygophyllum fabago)
Tree of Heaven (Ailanthus altissima)
Ventenata grass (Ventenata dubia)
White bryony (Bryonia alba)
Yellow bluestem (Bothriochloa ischaemum)
Yellow flag iris (Iris pseudacorus)
Weed Management Plan March 2021
Appendix B
Appendix B – Garfield County Noxious Weeds
Garfield County Listed Species (40)
Common Scientific
Absinth wormwood (Artemesia absinthium)
Black henbane (Hyoscyamus niger)
Bouncingbet (Saponaria officinalis)
Bull thistle (Cirsium vulgare)
Canada thistle (Cirsium arvense)
Chicory (Cichorium intybus)
Chinese clematis (Clematis orientalis)
Common burdock (Arctium minus)
Common tansy (Tanacetum vulgare)
Common teasel (Dipsacus fullonum)
Corn chamomile (Anthemis arvensis)
Curly dock (Rumex crispus)
Cutleaf teasel (Dipsacus laciniatus)
Cypress spurge (Euphorbia cyparissias)
Dalmatian toadflax (Linaria dalmatica)
Dame’s rocket (Hesperis matronalis)
Diffuse knapweed (Centaurea diffusa)
Hoary cress (Cardaria draba)
Houndstongue (Cynoglossum officinale)
Jointed goatgrass (Aegilops cylindrica)
Leafy spurge (Euphorbia esula)
Mayweed chamomile (Anthemis cotula)
Meadow knapweed (Centaurea pratensis)
Mediterranean sage (Salvia aethiopsis)
Musk thistle (Carduus nutans)
Myrtle spurge (Euphorbia myrsinites)
Oxeye daisy (Chrysanthemum leucantheum)
Perennial pepperweed (Lepidium latifolium)
Plumeless thistle (Carduus acanthoides)
Poison hemlock (Conium maculatum)
Purple loosestrife (Lythrum salicaria)
Russian knapweed (Acroptilon repens)
Russian olive (Elaeagnus angustifolia)
Salt cedar (Tamarix parviflora, Tamarix ramosissima)
Scentless chamomile (Tripleurospermum perforatum)
Scotch thistle (Onopordum acanthium)
Spotted knapweed (Centaurea maculosa)
Sulfur cinquefoil (Potentilla recta)
Yellow starthistle (Centaurea solstitalis)
Yellow toadflax (Linaria vulgaris)