HomeMy WebLinkAbout1.13 Reveg PlanExhibit L-2
Microgrid Energy
Revegetation Plan
for the
Ziegler Solar Garden Site
November 2017
Prepared By:
Habitat Management
Environmental & Natural Resource Services
Table of Contents
1 Introduction 1
2 Site Description 1
2.1 Location 1
2.2 Climate 1
2.3 Existing Vegetation 1
2.4 Soils 1
3 Revegetation Plan 2
3.1 Noxious Weed Management 2
3.2 Soil Amendments 2
3.3 Soil Decompaction 2
3.4 Soil Preparation 2
3.5 Seeding 2
4 References 3
Tables
Table 1: Ziegler Solar Garden Site Seed Mix (5.4 acres) 3
Habitat Management, Inc. i November 2017
Revegetation Plan for the Ziegler Solar Garden Site
1 Introduction
Microgrid Energy plans to install a solar energy farm on the pasture located east of 30985 US -6
Silt, Colorado. The Ziegler Solar Garden Site is approximately 5.4 acres with a service road
connecting it to a driveway, that connects to US -6. It is anticipated that site disturbance
associated with the installation of the solar garden will be limited with no stripping of vegetation
or soil grading.
2 Site Description
2.1 Location
The Ziegler Solar Garden Site is located east of 30985 US -6 Silt, Colorado. See site plans
provided by Microgrid Energy for the specific location. The completed site will contain 1 MW
(megawatt) of solar panels, associated equipment, and a primative road. The completed site will
be protected with a chain link or game style fence.
2.2 Climate
The site lies west of Silt, Colorado, at an elevation of 5,538 feet above sea level. The average
annual rainfall at the site is approximately 15 inches, and the average annual snowfall is 73
inches. Temperatures range from 13° F in winter to 90° F in summer
2.3 Existing Vegetation
The site is a former pasture that was used for cattle. Based on Habitat Managements survey on
October 30, 2017 the vegetation on the site consists of primarily Smooth Brome (Bromus
inermis), Western wheatgrass (Pascopyrum smithii), Rabbit Brush (Ericameria sp.), Russian
Thistle (Kali tragus), Canada Thistle (Cirsium arvense), Bull Thistle (Cirisium vulgare), and
Russian Olive (Elaeagnus angustifolia).
Canada Thistle, Bull Thistle, and Russian Olive are List B noxious weeds by the Colorado
Department of Agriculture (CDA) and Garfield County.
2.4 Soils
Soil at the site is classified as an Arvada, fine sandy loam derived from sodic shale parent
materials and is well drained with very slow permeability with high to very high potential for
runoff. The upper four inches of topsoil is a fine sandy loam texture with thin platey structure
and good organic matter content. Deeper soil horizons are clay loam to clay textured, natric (salt
affected) with high exchangeable sodium, strongly alkaline with high pH and electrical
conductivity. No conditions were observed during the October 30, 2017 field visit that warranted
soil sampling.
Minimal surface soil disturbance will occur during construction. If any excavation occurs to the
deeper natric and clay textured subsoils, extreme care will be taken to salvage any topsoil that
may be disturbed during construction. Due to the high salts and pH of the subsoils, these soils
will be excavated separately from the topsoil and replaced in the excavation and covered with
salvaged topsoil. Construction activities on these soils will occur during dry soil conditions to
minimize tracking and compaction.
Habitat Management, Inc. 1 November 2017
Revegetation Plan for the Ziegler Solar Garden Site
3 Revegetation Plan
Because minimal ground disturbance is anticipated and the site is currently well vegetated,
revegetation requirements are also anticipated to be minimal. Revegetation will occur on areas
greater than 50 square feet where at least 50% of the ground surface has exposed soil as a result
of construction operations. Large equipment such as drill seeders will be unable to access the site
after installation and all revegetation work will be completed using small equipment, such as
ATVs, or by hand. Revegetation efforts should take place in late winter or early spring as ground
conditions permit.
3.1 Noxious Weed Management
Noxious weed infestations at the site will hamper revegetation efforts and continue to displace
pasture vegetation. Noxious weed management will occur as outlined in the Noxious Weed
Management Plan, and will target state listed A and B -list noxious weed species as designated in
the Colorado Noxious Weed Act (CRS Title 35, Article 5.5). Annual weeds such as kochia and
Russian thistle (tumbleweeds) can be expected to occur on disturbed areas and will not pose a
long-term problem for the site, but will decrease as desirable vegetation becomes established.
3.2 Soil Amendments
As the site already supports an introduced pasture vegetation community, and subsoil is not
anticipated to be exposed after construction, no soil amendments are required at the site. The
topsoil has adequate organic matter and the use of fertilizer is not recommended.
3.3 Soil Decompaction
Areas with excessive soil compaction after construction will be decompacted using a small
agricultural disk pulled behind an ATV or small UTV (Utility Terrain Vehicle). Some areas may
be inaccessible due to the presence of the solar panels and disking will take place as necessary
and practicable. Small areas may also be decompacted by hand using rakes. Minimal mixing of
the topsoil with the high pH and sodic subsoils will be necessary to provide a suitable soil for
revegetation.
3.4 Soil Preparation
In areas accessible by equipment, the soil surface will be prepared for seeding using a tine
harrow pulled by an ATV or small UTV. Harrowing will provide an appropriate seed bed and
enhance seed -soil contact. Areas inaccessible by equipment will be raked by hand, as accessible.
Minimal mixing of the topsoil with the high pH and sodic subsoils should occur.
3.5 Seeding
All revegetation areas will be seeded using an appropriate salt tolerant native and improved
pasture seed mix developed specifically for the site (Table 1). Species selected for the seed mix
are those know to already occur at the site, as well as other pasture species known to be effective
for revegetation in the region. Because aggressive weed management will be necessary at the
site, only native and introduced pasture grasses will be used in the seed mix; grass species are
more tolerant of weed management actions which can harm forb species. Seed will be broadcast
on the site using a small ATV -mounted spreader, or by hand as practicable, at a rate of 75 pure
live seeds (PLS)/square foot (11.1 PLS lbs/acre).
Habitat Management, Inc. 2 November 2017
Revegetation Plan for the Ziegler Solar Garden Site
Ideally seeding will occur in winter, but frozen ground conditions may prevent soil preparation
until early spring. If frozen ground conditions persist, seeding may occur without soil preparation
to ensure seedlings access to any early -season precipitation that may occur. Additionally,
snowfall after seeding helps to ensure good seed -soil contact. Due to major wildfires in the
region, seed prices and availability are in flux. Recommended seed mixes are subject to change
based on regional market availability and price at the time of purchase.
Table 1: Ziegler Solar Garden Site Seed Mix (5.4 acres
Species
Common Name
Desired
Species
Comp.
(%)
Average
No.
Seeds/
Pound
Pounds
PLS/
Acre
PLS/
Sq.
Ft.
Graminoids
1111
Bouteloua gracilis
blue grama
10%
825,000
.40
7.5
Pascopyrum smithii
western wheatgrass
30%
110,000
8.91
22.5
Sporobolus airoides
alkali sacaton
25%
1,742,000
.46
18.8
Bromus inermis
Smooth brome
25%
125,000
6.53
18.8
Thinopyrum intermedium
Intermediate wheatgrass
10%
88,000
3.71
7.5
Combined Totals
100%
20.02
75
4 References
Colorado Department of Agriculture, Conservation Services Division Noxious Weed Program
Website. (http://www.colorado.gov/cs/Satellite/ag_Conservation/CBON/1251618780047)
[accessed November 2017]
Colorado Revised Statutes Title 35, Article 5.5- Colorado Noxious Weed Act and rules
pertaining to the Administration and Enforcement of the Colorado Noxious Weed Act.
Soil Survey Staff, Natural Resources Conservation Service, United States Department of
Agriculture. Web Soil Survey. Available online at the following
link: https://websoilsurvey.sc.egov.usda.gov/. Accessed [11/021/2017].
USDA, NRCS. 2017. The PLANTS Database (http://plants.usda.gov, 2 November 2017).
National Plant Data Team, Greensboro, NC 27401-4901 USA.
Western Regional Climate Center. Western Regional Climate Center Historical Climate
Information. http://www.wrcc.dri.edu [accessed November 2017].
Habitat Management, Inc. 3 November 2017