HomeMy WebLinkAbout20071531 Ver 1_Stone Ridge at Hayes Mountain (2)_20070910p 7- 1 5 3 1
StoneRidge at Hayes Mountain
Stream and Wetland Mitigation Plan
Buncombe County, North Carolina
August 29, 2007
Prepared by:
PO Box 882
Canton, NC 28716
Project Description
The project site known as StoneRidge at Hayes Mountain is owned by SJH
Enterprises, LLC, and is located off of Ridge Road near Enka, North Carolina.
The site contains land in Buncombe County. Latitude and longitude for the site
are 35.351247 N and 82.424428 W, respectively. The site is located within the
Enka USGS Topo Quad.
SJH Enterprises, LLC proposes to develop the property as a residential
community on approximately 63.83 acres. Stream enhancement totaling 250
linear feet and wetland enhancement and littoral shelf establishment totaling
0.103 acre will be used as mitigation. The overall goal of the enhancement
activities on site will be to provide a structurally stable hydrologic system where
historic livestock activities have degraded the stream and wetland systems. The
stream is a first order unnamed tributary to Pole Creek which drains to Hominy
Creek then to the French Broad River. The stream has a 15 acre watershed.
Enhancement Plan
The developer of StoneRidge plans to enhance 250 linear feet of stream and
0.07 acre of wetland. The goals of the project are:
1. Stabilize banks and reduce erosion.
2. Create and preserve a riparian buffer with permanent native vegetation.
3. Create aquatic habitat and complexity.
4. Re-slope and stabilize banks around wetland.
5. Enhancement of wetland vegetation (to extend beyond current wetland).
Construction Plan and Specifications
Construction activities will include the systematic re-sloping of banks including
bankful benches along the stream. The eroded banks surrounding the wetland
will be re-sloped as well. A description of each treatment is described below.
Re-slope Banks
In areas where the banks can be re-sloped, this method will be used instead of
toe armor. Vertical banks will be graded at a slope of 2:1 or flatter. Where
appropriate, accessible bankfull benches will be established to reduce sheer
stress on banks. Newly sloped banks will be graded into the existing stream
banks. Any disturbed soil will be stabilized with erosion matting and planted with
native vegetation. Existing mature trees will be preserved unless the stream
bank erosion has damaged the tree.
Monitoring Plan
After construction completion, WNR staff will provide the resource agencies with
a baseline monitoring report. Monitoring activities will take place every year for
5 years after construction completion. An annual monitoring report will be
submitted each year following the monitoring activities. WNR will conduct
monitoring and SJH Enterprises, LLC will provide the financial assurance that will
ensure this project is complete and successful.
An as-built report will be included with the first annual monitoring report. At
least two bankfull events in separate years will be documented within 5-year
monitoring period. If two bankfull events have not been documented, stream
monitoring will continue until two bankfull events have occurred in two separate
years. Success will be measured in terms of channel stability and plant survival.
Problem areas identified in during any part of annual monitoring activities will be
discussed with project partners. Any necessary remedial actions will be planned,
approved, and implemented.
Monitoring Parameters
1.0 Channel Stability
1.1 Cross Sections
1.2 Pebble Counts
2.0 Plant Survival
2.1 Monitoring Plots
3.0 Photographic Reference Sites
4.0 Biological Monitoring
1.0 Channel Stability
Channel stability will be measured through the following two parameters: cross-
sections and pebble counts; and then compared to previous measurements.
Four permanent cross-sections will be set up on the stream representing 50%
pools and 50% riffles. Pebble counts will be performed at each cross section. If
there is substantial evidence of instability, such as down-cutting or erosion,
remedial actions will be taken.
2.0 Plant Survival
Vegetative success will be measured in terms of plant survival. Plant survival will
be measured with stem counts in designated vegetative monitoring plots. Stem
counts of at least 320 stems/acre in year 3 and 260 stems/acre in year 5 will be
considered successful. Vegetative monitoring plots, 1/10 acre in size, will be set
up adjacent to each cross section. Plant survivability will be assessed using
these vegetative monitoring plots. If there is substantial plant mortality that
leads to lowered stem counts, remedial actions will be taken.
Areas with less than 75% vegetation coverage will be re-seeded and/or fertilized;
and live stakes and bare rooted trees will be planted to achieve the desired
densities. Exotic, invasive, and invader species will be removed so that they will
not exceed 20% of the vegetative composition.
3.0 Photographic Reference Sites
Photos will be taken at each cross section as well as other monumented
reference sites throughout the stream reach. These photos will indicate
aggradation, degradation, and/or bank erosion. If none exists, no remedial
action will be required. If aggradation, degradation, and/or bank erosion occurs,
the problem will be accessed and remedial actions will be planned, approved,
and implemented.
4.0 Biological Monitoring
Benthic macroinvertebrate sampling will be conducted before the project begins
and will continue for at least three years of monitoring after project completion.
Planting Plan and Specifications
The objective will be to mimic most of the natural buffer that is on site,
which is mainly composed of shrubs and trees. However, warm season grasses
will be used, in accordance with the ~~Warm Season Grass Establishment and
Management in North Carolina and Virginia" provided by the US Fish and Wildlife
Service as a temporary planting to aid with soil stabilization.
Recommended Native Species for Stream Restoration
Trees
Yellow Buckeye Aescu/us octandra
Sweet Birch Betu/a /enta
River Birch Betula nigra
Bitternut Hickory Carya cordiformis
Shagbark Hickory Carya ovata
Persimmon Diospyros virginiana
Green Ash Fraxinus pennsy/vanica
Carolina Silverbell Ha/esia caro/iniana
Blackgum Nyssa sy/vatica
Sycamore P/atanus occidentalis
Black Cherry Prunus serotina
Black Willow Sa/ix nigra
White Basswood Tilia heterphylla
Small Trees and Shrubs
Tag Alder A/pus serru/ata
Serviceberry Ame/anchier arbrea
Red Chokeberry Aronia arbutifolia
Common Pawpaw Asimina triboba
Sweet-shrub Calycanthus floridus
Ironwood Carpinus caroliniana
Alternate Leaf Dogwood Corpus a/ternifo/ia
Silky Dogwood Corpus amomum
Hazel-nut Cory/us Americana
Witch Hazel Hamame/is virginiana
Winter Berry I/ex verticillata
Doghobble Leucothoe axil/cries
Spicebush Lindera benzoin
Male-berry Lyon/a /igustrina
Umbrella Tree Magno/ia tripeta/a
Ninebark Physocarpus opulifolius
Wild Azalea Rhododendron peric/ymenoides
Swamp Azalea Rhododendron viscosum
Swamp Rose Rosa pa/ustris
Silky Willow Sa/ix sericea
Meadowsweet Spirea /atifolia
Sweet Leaf Symplocos tinctoria
Wihe-rod Viburnum cassinoides
Yellow-root Xanthorhiza situp/icissima
Herbaceous
Jack-in-the-Pulpit Arisaema triphy//um
Swamp M i I kweed Asc%pias incarnate
Fringed Sedge Carex crinata
Bladder Sedge Carex intumescens
Hop Sedge Carex /upu/ina
Lurid Sedge Carex /urida
Broom Sedge Carex scoparia
Tussock Sedge Carex stricta
Fox Sedge Carex vu/pinoides
Turtlehead Che%ne g/abra
Umbrella Sedge Cyperus strigosus
Bottlebrush Grass E/ymus hystrix
Joe-Pye Weed Eupatorium fistu/osum
Boneset Eupatorium pen`oliatum
Jewelweed Impatiens capensis
Soft Rush Juncus effuses
Rice Cutgrass Leersia oryzoides
Cardinal Flower Lobe/ia cardina/is
Great Blue Lobelia Lobe/ia siphi/itica
Seedbox Ludwigia a/ternifolia
Switchgrass Panicum virgatum
Tea rth u m b Polygonum sagittatum
Green Bulrush Scirpus atrovirens
Woolgrass Scirpus cyperinus
Soft Stem Bulrush Scirpus va/idus
Bur-reed Sparganium americanum
March Fern Theypteris pa/ustris
River Oats Uniola /atifolia
Ironweed I/ernonia noveboracensis
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Photo 2. Eroded Banks and Poor Water Quality.
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Photo 1. Cattle Impacted Stream.
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Photo 4. Cattle Impacted Wetland.
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Mitigation Required
T e of Im act Amount
LF or Acrea a Mitigation Ratio
Based on Stream Multiplier
Based on Im act
Final Ratio Mitigation
LF or Acrea e
Dam & Culvert Pi e & Ri -Ra 88 1:1 Poor Qualit 1 for fill 1:1 88
Floodin 140 1:1 Poor Qualit 1 /2 for floodin .5:1 70
Pond & Culvert Pi e & Fill 0.03 1:1 Poor Qualit 1 for fill 1:1 0.03
Floodin 0.082 1:1 Poor Qualit 1/2 for floodin .5:1 0.041
Total Stream Impact 228 LF
Total Wetland Impact 0.112 Acre
Mitigation Proposed by Type
Total 158 LF
Total 0.071 Acre
Type of Mitigation Method Ammount Proposed Multiplier SMU
Stream Enhancement Level II On-Site 250 1.5 166.666667
Wetland Littoral Shelves On-Site 0.033 1 0.033
Wetland Enhancement On-Site 0.07 1.5 0.047
Total 167 LF
Total 0.080 Acre
Surplus 9 LF
Surplus 0.009 Acre