HomeMy WebLinkAboutFPA2006-00026 SEP2006-00128 - FPA Permit / Conditions - 6/6/2010 (2) ESA LISTED SALMONIDS CHECKLIST
Applicant Information Project Information
Name RE D Fl Lfl SToc. q N C- Name N A
Phone 3 GO -3 3 9- Z?O$ Location P,S I GL K 3 LoT 1.3 LY- Gu:5141AN
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This worksheet was designed to help project proponents, and government agencies, identify
when a project needs further analysis regarding adverse effects on ESA (Endangered Species
Act) listed salmonids. Salmonids are salmon, trout and chars, e.g. bull trout. For our purposes,
"ESA Listed Salmonids" is defined as fish species listed as endangered, threatened or being
considered for listing.
If ESA listed species are present or ever were present in the water shed where your project will
be located, your project has the potential for affecting them, and you need to comply with the
ESA. The questions in this section will help determine if the ESA listings will impact your
project.
The Fish Program Manager at the appropriate Department of Fish and Wildlife (DFW) regional office can provide
information for the following two questions.
1. Are ESA listed salmonids currently present in the watershed in which your project will be
located? YES NO Please describe.
2. Has there ever been an ESA listed salmonid stock present in this watershed?
YES NO N Uncertain Please describe.
If you answered "yes" to either of the above questions, you should complete the remainder
of this checklist.
RECEIVED
A § 6
AEA
April 2003
- 1 -
FISH MIGRATION: The following questions will help determine if this project could
interfere with migration of adult and juvenile fish.
Both increases and decreases in water flows can affect fish migration.
1. Does the project require the withdrawal of:
a. Surface water? YES NO
Amount
Name of surface water body
b. Ground water? YES NO
Amount
From where
Depth of well
2. Will any water be rerouted: YES NO
If yes,will this require a channel change?
3. Will there be retention or detention ponds? YES NO
If yes, will this be an infiltration pond or a surface discharge to either a municipal storm
water system or a surface water body?
If to a surface water discharge, please give the name of the waterbody.
4. Will this project require the building of new roads?. YES NO
Increased road mileage may affect the timing of water reaching a stream and may impact fish habitat.
5. Are culverts proposed as part of this project? YES NO
6. Will topography changes affect the duration/direction of runoff flows?
YES NO If yes, describe the changes.
7. Will the project involve any reduction of the floodway or floodplain by filling or other
partial blockage of flows? YES NO If yes, how will the loss of flood
storage be mitigated by your project?
-3 -
VEGETATION: The following questions are designed to determine if the project will
affect riparian vegetation, thereby, adversely impacting salmon.
1. Will the project involve the removal of any vegetation from the stream banks:
YES NO
If yes, please describe the existing conditions, and the amount and type of vegetation to be
removed.
2. If any vegetation is removed, do you plan to re-plant?
YES NO If yes,what types of plants will you use?
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TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
Mason County DCD
Planning Division
PO Box 279
Shelton, WA 98584
Redfield Stocking
9805 Whitecap Drive NW
Olympia, WA 98502
(360) 339-2705
RE: Geotechnical Report
Case No.
Parcel No. 42333-51-03013
Cushman Eastside 1, Blk 3, Lot 13
Forest Service Road No. 2300
Hoodsport, WA 98548
INTRODUCTION
I was contacted by Redfield"Red" Stocking early this year and was requested to
investigate and document slope stability and landslide hazard issues relating to the
residential development of Mason County Property Tax Parcel Number 42333-51-03013,
otherwise know as the assessor's plat of Lake Cushman—Eastside No.1, Block 3, Lot 13
located on Forest Service Road 2300. The property is located approximately 1-1/4 miles
up the Dow Mountain Road behind the Lake Cushman Maintenance Office which is
located approximately 4 miles west of Hoodsport on the Cushman Road (SR-119).
The property is a five acre parcel measuring roughly 930'+along its long/north-south
axis, and roughly 240' along its east-west axis. Property dimensions are shown on the
attached site plan.
The Stockings wish to develop the property with a three bedroom residence. A three
bedroom On-site Septic System(OSS) design is being developed.
The following ten elements are required by Mason County to be addressed in
geotechnical reports prepared to comply with Mason County's Critical Resource
Ordinance Sections 17.01.100 through 17.01.104
1. SURFACE AND GEOLOGIC CONDITIONS:
The property has been logged in the past, and has medium aged second growth fir,
hemlock, and cedar tress growing evenly throughout the property. Besides the conifers,
File:C:IProjectslStockinglGeolGeo-Rpt.doc 1 of 5 5/11/2006
A
a
I
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
the property has Maple, Alder, Vine Maple, and a moderate covering of Salal, Oregon
grape, ferns, and other vegetation. The Series 1950,No. 9 SOIL SURVEY of Mason
County indicates the site soils are Classified as Rc which is described as "rough
mountainous land, Hoodsport soil material". These soils typically result from the
weathering of the glacial till soils found underlying much of the area. Fractured and solid
basalt rock is typically found from depths of a few feet to 30 to 50' beneath the till
layer(s). The Hoodsport soil types are prone to neither erosion, or liquefaction, and are
not listed in Mason County's Resource Ordinance as an erodible soil or an erosion
hazard. The Hoodsport soils are typically describes as excessively drained, and typically
are composed of a fairly high percentage of cobbles or gravels. The soil is also
comprised of varying ratios of fines, including silts and clays, which may comprise as
high as 12 or 15% of the soil volume. The soils on the Stocking site contain a moderate
amount of fines, along with a random mixture of sand, gravels and cobbles, and are
generally the weathered surface of the glacial till soils underlying the whole region. The
soil provides good foundation support in its undisturbed state, but must be properly
placed and compacted if fill sections are expected to provide reliable bearing.
The northerly third of the property contains slopes ranging from 20 to 30%. The
southerly two-thirds of the property lies on slopes generally averaging 30 to 45% slopes.
The main property development is planned on the northerly portion of the property.
Development on the southerly part of the property is not planned at this time other than
pioneering in a short road and flat area to accommodate a water well. If this is pursued,
the road and landing would be located not far south from the Forest Service Road. A
conjectural well location is shown on the plan sheet. The well may also be placed
somewhere in the northerly area of the property, but this decision is still being made.
Further consideration of the soils found on site lead to describing the soils in terms of the
Unified Soil Classification System(USCS) criteria, and describing the soils as a GP
(gap-graded gravels or uniform gravels, sandy gravels), or even more likely as GM (silty
gravels, silty sandy gravels). These soil designations were used in characterizing the soil
for stability analysis.
2. DEVELOPMENT AND GEOLOGIC FEATURES:
A site plan has been developed for this property and is attached in the appendixes. The
final location and size of the planned residence is still being finalized. Though the
property contains slopes in the 40%+range, they roughly represent the underlying glacial
till surface, and may be considered very stable.
3. LOCATIONS OF LOGS OF EXPLORATORY HOLES OR PROBES:
An inspection of the slopes and cuts in the subject property's vicinity was performed and
compared with the Mason County Soil Survey soil descriptions. The cuts and soil layers
observed around the area confirm the soils as generally being medium dense soil horizons of
weathered Vashon glacial till to a depth around 3-feet where it becomes more dense and can
File:C:IProjectslStockinglGeolGeo-Rpt.doc 2 of 5 5/11/2006
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
be characterized as hardpan. The soil logs dug for designing the On-Site Septic System
design found permeable soils to depths of 60 plus inches in the primary drainfield area, and a
minimum 36 inches in the proposed reserve drainfield(DF) area.
4. CROSS SECTION WITH PROPOSED GRADE CHANGES:
A cross section is included in the appendix. Grade changes will mainly be for the
purpose of constructing an access driveway from the Forest Service Road to the proposed
building area, and the leveling of the building area itself. The proposed residence will be
excavated into the hillside, with the entire foundation sited on undisturbed native soil,
mainly the till layer. The yard area in front (to the south) of the residence may be
enlarged by wasting the soils produced from excavating the structures' basement or
foundations. Any fill placed on the property will be placed in compliance with the
County's grading ordinance requirements, which require fill placed on slopes steeper
than 20% , to be place on a level bench excavated for the purpose of providing a stable
area to construct the engineered fill slope on. Fill receiving areas will be cleared of
vegetation, and a level bench, a minimum of 6-feet wide, will be excavated so that the fill
slope may be constructed in uniform 6 to 12"thick"lifts" of fill soil, compacted to 90+%
compaction before subsequent lifts of fill are placed. Fill slopes constructed in this
manner, may be constructed to the County's standard 2:1 (H:V 50%) fill slope
geometry. Excavation on the uphill side of the road, and for the building foundation is
expected to be dug out of the hardpan layer, and may be excavated at a maximum 1:1
slope (H:V).
5. SLOPE STABILITY ANALYSIS:
The steepest slopes on the property in its present condition contain no obvious recent
mass landslides or stability problem indicators. The proposed building area in the central
area of the northerly portion of the property has no discernible irregularities, settlements,
fissures, or evidence of consolidation problems.
Unified Soil Classification System typing laces the soils in a coarse rained soil GM
Y Yp g P g ( )
classification with a dry density between 120-135 lbm/ft3 and a typical effective stress
friction angle (0)>340. The surface soil layers appear to be a relatively dirty gravel, so
a GP soil classification may also be appropriate with the same dry density and phi angle.
A soil density of 130 Ibs/ft3 will be used in the stability analysis.
Slope stability calculations are addressed on an Excel spreadsheet following the plans.A
phi angle of 36' for the soil internal friction angle was used along with a cohesion value
of 300 lbs per W. The glacial till soils can be modeled with cohesion values as high as
1000 lbs per ft2, and with internal friction angles above 40°, so the analysis is based on
conservative assumptions.Foundations bearing on the medium dense and dense
Hoodsport gravelly sandy loams can expect to realize bearing capacities of the natural
soil in the 1000 to 2000 pounds per square foot range, with settlement for residential
foundations within half an inch overall.
File:C:IProjectslStockinglGeolGeo-Rpt.doc 3 of 5 5/11/2006
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
6. RECOMMENDED SETBACKS & DRAINAGE:
The property contains only isolated areas of relatively level ground, and will require
construction on what may be classified as potentially unstable ground.No structures should
be planned to be placed on fill material,unless the fill is placed as structural fill under the
supervision of an engineer, or an engineering geologist. So long as the residences' footings
are constructed on the natural glacial till, a building setback from the crest of the slope is not
needed. Footings should be buried on their downslope side enough to protect them from
freeze-thaw actions. For this area(Cushman/Olympic foothills), a minimum 18" of soil cover
should be placed above all footings.
Drainage from the developed property should be directed into the naturally vegetated areas of
the property. Concentrated discharges of collected stormwater runoff should be avoided.
Collected stormwater runoff should be dispersed as close to its source as practical and
allowed to seep into the ground. Sensitive areas like the septic drainfield area should be
protected from the delivery of any stormwater flows in its vicinity. Driveway runoff should
be dispersed as frequently as possible into the surrounding vegetation. Water bars, and
driveway cross culverts on no greater than 200' intervals should be planned as part of the
property development.
Roof runoff may be dispersed at downspout splash blocks, and directed away from the
foundation into the yard area.
7. CLEARING, GRADING, AND VEGETATION MANAGEMENT:
Clearing for the residence, a driveway, and a possible well location will be necessary for
development of the property. Besides removing trees for the building and driveway
footprints, danger trees (potentially threatening to the residence)may be planned to be
removed.Aside from clearing and grading the property for the residence and driveway, no
clearing or grading on other parts of the property is planned.
Once a residence is constructed on the property, bare areas will be planted with grass and
landscape plantings. Overall, it appears the development of the property will have a minor
impact on the property itself, and little or no impact to surrounding properties.
8. EROSION AND SEDIMENT CONTROL:
As indicated earlier in this report,the site's soils are not considered erodible, and minimal
Erosion and Sediment(E&S) Control measures should be adequate to protect neighboring
properties and State waters. Access to the site will be developed off of the Forest Service
Road (private), roughly a mile away from any public roads. Construction of the proposed
driveway will include a driving surface of clean gravel or crushed rock.
The major earthwork will be leveling the house's building location, excavating the footing
trenches, and constructing the driveway. These development areas drain mainly to the
owner's property, and will have approximately 20+-feet of vegetative to pass through before
any runoff exits the property at its normal discharge locations.
File:C:IProjectslStockinglGeolGeo-Rpt.doc 4 of 5 5/11/2006
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
The existing and proposed features should provide adequate protection against adverse
stormwater runoff impacts.
9. ON-SITE AND OFF-SITE IMPACTS:
Construction and completion of the proposed improvements are not expected to result in
any adverse on-site, or off-site impacts. The proposed residential development of the
property will not result in adverse impacts to either the subject property or to neighboring
properties.
10 SPECIFICATIONS OF FINAL DEVELOPMENT CONDITIONS:
The completed site will be allowed to return, for the most part, to a naturally vegetated state.
The main ground cover will be lawn and medium height shrubbery.
In the future development of the property, discharging concentrations of collected
Stormwater runoff within 20 feet of a property boundary should be avoided.
Conclusions and Summary;
The residential development of the Stocking property located in the Dow Mountain area
of Lake Cushman does not appear to present any stability problems that cannot be
overcome, and will not result in any undesirable impacts.
The property itself provides an adequate vegetated buffer area to protect neighboring
properties and State Waters from adverse stormwater runoff impacts. The stormwater
related recommendations made in this report should be adequate for both temporary and
permanent stormwater runoff management and concerns.
I hope this report meets the needs of the Stockings, and Mason County in planning the
property's development.
WAS
Sincerely,
Alan A. Tahja, P.E.
07g'%
Attached: Site Plan (Plan Sheets I & 2) MtC3NA1.
Cross Section (Plan Sheet 3)
Stability Analysis (Excel Spreadsheet)
File:C:IProjectslStockinglGeolGeo-Rpt.doc 5 of 5 5/11/2006
Revision# Description Date TAHJA ENGINEERING,Inc. STOCKIIVG SITE PLAN "'`"'`
Alan Tahja,P.E. Redfield Stocking Stocking
PO Box 235 9805 Whitecap Drive NW
Hoodspo4 WA 98548 Olympia, WA 98502 1 of 3
County Prcl No. 42333 5103013 (360)877-9512 (360) 339-2705
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Revision# Description Date TAHJA ENGINEERING,Inc. STOCKING SITE PLAN Froj.Fffe
Alan Tahja,P.E. Redfield Stocking Stocking
PO Box 235 9805 Whitecap Drive NW
HoodspoA WA 98548 Olympia, WA 98502
360 877-9512 360 339-2705 2 of 3
CountyPrcl No. 42333 5103013 ( ) � )
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Revision# Description Date TAHJA ENGINEERING,Inc. STOCKING SITE PLAN N4.F&
Alan Tahja,P.E. Redfield Stocking Stocking
PO Box 235 9805 Whitecap Drive NW s
Hoodspoi t, WA 98548 Olympia, WA 98502 3 of 3
CountyPrcl No. 42333 5103013 (360)877-9512 (360) 339-2705
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Stocking Stability Analysis
Mason County Parcel Number 42333-51-03013
Slope Stability Analysis Section A-A
Weight
Slip Plane Angle: 452 kip
200
3470 SF
Slip Plane Length=260'
t170
Normal Force 1120
0+00 0+50 1+00 1+50 2+00 2+50 3+00 3+50 4+00
Factor of Safety (FS) is to be calculated against sliding -Static Conditions
FS = Resisting force/ Driving force
_ [c'L + N'x Tan(9)]/[W x sin(a)]
_ [c'L + (W x cos(a) - U x L) x tan(6)]/[W x sin(a)] _
where;
FS = Factor of Safety against sliding t 1/7/2Ep�
c' = drained shear strength of the slide plane (c' - 300 psf for med dense glacial till
6= angle of internal friction (360 used)
L = Length of slip plane surface (260')
N = normal force : perpendicular to slip plane (N =W x cos(a))
W= total weight of failure wedge (130 pcf x 3470') = 451,100 Ibs=452 kip)
u= average pore water pressure along the slip surface (psf) = 0 for gravelly loam sands
a= Slope/Slip Plane Angle (110)
FS = [(.3 x 260)+[452 x cos(11°)-(0 x 260)] x tan(36)]/ [452 x sin(11°)]
_ [(78+(443.7)(0.9816)]/86.2 = 400/86.2 =4.64
4.64 > 1.5 OK
Factor of Safety(FS) against sliding - Dynamic Conditions (Seismic Factor b = 0.3)
FS = [c'L + (W x cos(a) - b x W x sin(a) - U x L) x tan(6)]/[W x sin(a) + b x W x cos(a)]
"=[(.3x260+(452xcos(11°)-.3x452xsin(11 0)-Ox260)xtan(36)]/(452xsin(11)+.3x452xcos11°
_ (78 + (443.7-25.9 -0) x .7265)/[86.2 + 133.1]
= 381.5/219.4 = 1.74 > 1 OK
TAHJA ENGINEERING, Inc. 5/11/2006
o� STATE O�
Y N Y M V
SEP 1 3 2006
0
by lass�
STATE OF WASHINGTON MIMN CCU,' P u,J"rMG RED,
DEPARTMENT OF ECOLOGY
PO Box 47775 • Olympia, Washington 98504-7775 • (360) 407-6300
September 12,2006
Ms. Tammi Clark
Department of Community Development
Mason County Planning Division
PO BOX 279
Shelton, WA 98584
Dear Ms. Clark:
Thank you for the opportunity to comment on the mitigated determination of nonsignificance for the
Stocking Clearing for a Cabin(SEP2006-00128), located at Lake Cushman Eastside#1 Block 3,Lot 13,
as proposed by Redfield Stocking. The Department of Ecology(Ecology)reviewed the environmental
checklist and has the following comment(s):
WATER QUALITY: Roberta Woods(360) 407-6269
Any discharge of sediment-laden runoff or other pollutants to waters of the state is in violation of
Chapter 90.48 RCW,Water Pollution Control, and WAC 173-201A, Water Quality Standards for
Surface Waters of the State of Washington, and is subject to enforcement action.
Erosion control measures must be in place prior to any clearing, grading, or construction. These
control measures must be effective to prevent stormwater runoff from carrying soil and other
pollutants into surface water or storm drains that lead to waters of the state. Sand, silt, clay particles,
and soil will damage aquatic habitat and are considered to be pollutants.
Proper disposal of construction debris must be on land in such a manner that debris cannot enter the
natural stormwater drainage system or cause water quality degradation of state waters.
During construction,all releases of oils, hydraulic fluids, fuels, other petroleum products, paints,
solvents, and other deleterious materials must be contained and removed in a manner that will prevent
their discharge to waters and soils of the state. The cleanup of spills should take precedence over
other work on the site.
Clearing limits and/or any easements or required buffers should be identified and marked in the field,
prior to the start of any clearing, grading, or construction. Some suggested methods are staking and
flagging or high visibility fencing.
Provision should be made to minimize the tracking of sediment by construction vehicles onto paved
public roads. If sediment is deposited, it should be cleaned every day by shoveling or sweeping.
Water cleaning should only be done after the area has been shoveled out or swept.
«1
September 12,2006
Page 2
Ecology's comments are based upon the information provided with the SEPA checklist. As such,they do
not constitute an exhaustive list of the various authorizations that must be obtained or legal requirements
that must be fulfilled in order to carry out the proposed action.
If you have any questions or would like to respond to these comments please contact the appropriate
reviewing staff listed above.
Department of Ecology
Southwest Regional Office
(DN: 06-7372)
cc: Roberta.Woods, WQ
Redfield Stocking(Proponent)
SEP-12-2006 TUE 12:54 PM DOE SW REGIONAL OFFICE FAX NO. 360 407 6305 P. 01
t FAX NUMBER_
FAX COVER SHEET
DATE: TIME: # OF PAGES
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SEP-12-2006 TUE 12:54 PM DOE SW REGIONAL OFFICE FAX NO. 360 407 6305 P. 02
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STATE OF WASHINGTON
DEPARTMENT OF EC
PD Box 47775. O/YmP'a' W-7-'hingt0n 98504-777 sO 1 Y
(360)407-6300
September 12,2006
Ms. Tammi Clark
Depaftent of Community
Mason County Planning Division
°pment
PO Box 279
Shelton, WA 98584
Dear Ms. Clark:
Thank you for the o
Stockingpporturuty to comment on the mitigated determination ofnonsignificance fo
Clearing fora Cabin(SEP2006-00128), located at Lake Cushman
as proposed by Redfeld Stockin r the
checklist and has the followin co The Department ofEcolo Eastside#1 Block 3, Lot 13,
g mment(s): g3'(Ecology)reviewed the environmental
WATER QUALITY:Roberta Woods(360)407-6269
Any discharge of sediment-laden di de
n runoff or other pollutants
Chapter 90.48 RC WWater to waters of the state is in violation of
Surface Waters of the State ofoW soh nCn, I and WAC 173-201A
and is subject to enforcement actter tiion Quality Standards for
Erosion control measures must be in place prior to any clearing,grading,control measures must be effective to prevent stormwater runoff from carrying
pollutants into surface water or storm drains that lead at waters of g, °r construction. These
and soil will damage aquatic habitat and are considered to be of f t ate. soil and other
the state. Sand, silt, clay particles,
Proper disposal of construction debris must be on land in such ants.
natural stormwater drainage system or cause water quality
g y a manner that debris cannot enter the
During construction, all releases of oils h q degradation of state waters.
solvents,and other deleterious materials must be contained and removed in
hydraulic fluids,fuels, other petroleum products,paints,
their discharge to waters and soils of the state. The cleanup of spills should
other work on the site, a manner that will prevent
take precedence over
Clearing limits and/or any easements or required buffers should be identified
Prior to the start of any clearing,
grading, or construction. Some suggest
and marked in the field,
flagging or high visibility fencing. ggested methods are staking and
Provision should be made to minimize the tracking of sediment by construction public roads, If sediment is deposited, it should be cleaned every day b sho
Water cleaning should only be done after the area has been shoveled taon vehicles onto paved
Y veIing or sweeping
out or swept.
SEP-12-2006 TUE 12:55 PM DOE SW REGIONAL OFFICE FAX NO. 360 407 6305 P. 03
September 12,2006
Page 2
Ecology's'comments are based upon the information provided with the SEPA checklist. As such,they do
not constitute an exhaustive list of the various authorizations that must be obtained or legal requirements
that must be fulfilled in order to carry out the proposed action.
If you have any questions or would like to respond to these comments please contact the appropriate
reviewing staff listed above.
Department of Ecology
Southwest Regional Office
(DN: 06-7372)
cc:. Roberta Woods,WQ
Redfield Stocking(Proponent)
s'
a
4
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
Mason County DCD
Planning Division
PO Box 279
Shelton, WA 98584
Redfield Stocking
9805 Whitecap Drive NW
Olympia, WA 98502
(360) 339-2705
RE: Geotechnical Report
Case No.
Parcel No. 42333-51-03013
Cushman Eastside 1, Blk 3, Lot 13
Forest Service Road No. 2300
Hoodsport, WA 98548
INTRODUCTION
I was contacted by Redfield"Red" Stocking early this year and was requested to
investigate and document slope stability and landslide hazard issues relating to the
residential development of Mason County Property Tax Parcel Number 42333-51-03013,
otherwise know as the assessor's plat of Lake Cushman—Eastside No.1, Block 3, Lot 13
located on Forest Service Road 2300. The property is located approximately 1-'/a miles
up the Dow Mountain Road behind the Lake Cushman Maintenance Office which is
located approximately 4 miles west of Hoodsport on the Cushman Road (SR-119).
The property is a five acre parcel measuring roughly 930'+along its long/north-south
axis, and roughly 240' along its east-west axis. Property dimensions are shown on the
attached site plan.
The Stockings wish to develop the property with a three bedroom residence. A three
bedroom On-site Septic System(OSS)design is being developed.
The following ten elements are required by Mason County to be addressed in
geotechnical reports prepared to comply with Mason County's Critical Resource
Ordinance Sections 17.01.100 through 17.01.104
1. SURFACE AND GEOLOGIC CONDITIONS:
The property has been logged in the past, and has medium aged second growth fir,
hemlock, and cedar tress growing evenly throughout the property. Besides the conifers,
File: C:IProjectslStockinglGeolGeo-Rpt.doc I of 5 5/11/2006
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
the property has Maple, Alder, Vine Maple, and a moderate covering of Salal, Oregon
grape, ferns, and other vegetation. The Series 1950, No. 9 SOIL SURVEY of Mason
County indicates the site soils are Classified as Rc which is described as "rough
mountainous land, Hoodsport soil material". These soils typically result from the
weathering of the glacial till soils found underlying much of the area. Fractured and solid
basalt rock is typically found from depths of a few feet to 30 to 50' beneath the till
layer(s). The Hoodsport soil types are prone to neither erosion, or liquefaction, and are
not listed in Mason County's Resource Ordinance as an erodible soil or an erosion
hazard. The Hoodsport soils are typically describes as excessively drained, and typically
are composed of a fairly high percentage of cobbles or gravels. The soil is also
comprised of varying ratios of fines, including silts and clays, which may comprise as
high as 12 or 15% of the soil volume. The soils on the Stocking site contain a moderate
amount of fines, along with a random mixture of sand, gravels and cobbles, and are
generally the weathered surface of the glacial till soils underlying the whole region. The
soil provides good foundation support in its undisturbed state, but must be properly
placed and compacted if fill sections are expected to provide reliable bearing.
The northerly third of the property contains slopes ranging from 20 to 30%. The
southerly two-thirds of the property lies on slopes generally averaging 30 to 45% slopes.
The main property development is planned on the northerly portion of the property.
Development on the southerly part of the property is not planned at this time other than
pioneering in a short road and flat area to accommodate a water well. If this is pursued,
the road and landing would be located not far south from the Forest Service Road. A
conjectural well location is shown on the plan sheet. The well may also be placed
somewhere in the northerly area of the property, but this decision is still being made.
Further consideration of the soils found on site lead to describing the soils in terms of the
Unified Soil Classification System (USCS) criteria, and describing the soils as a GP
(gap-graded gravels or uniform gravels, sandy gravels), or even more likely as GM (silty
gravels, silty sandy gravels). These soil designations were used in characterizing the soil
for stability analysis.
2. DEVELOPMENT AND GEOLOGIC FEATURES:
A site plan has been developed for this property and is attached in the appendixes. The
final location and size of the planned residence is still being finalized. Though the
property contains slopes in the 40%+range,they roughly represent the underlying glacial
till surface, and may be considered very stable.
3. LOCATIONS OF LOGS OF EXPLORATORY HOLES OR PROBES:
An inspection of the slopes and cuts in the subject property's vicinity was performed and
compared with the Mason County Soil Survey soil descriptions. The cuts and soil layers
observed around the area confirm the soils as generally being medium dense soil horizons of
weathered Vashon glacial till to a depth around 3-feet where it becomes more dense and can
File: C:IProjectslStockinglGeolGeo-Rpt.doc 2 of 5 5/11/2006
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
be characterized as hardpan. The soil logs dug for designing the On-Site Septic System
design found permeable soils to depths of 60 plus inches in the primary drainfield area, and a
minimum 36 inches in the proposed reserve drainfield(DF) area.
4. CROSS SECTION WITH PROPOSED GRADE CHANGES:
A cross section is included in the appendix. Grade changes will mainly be for the
purpose of constructing an access driveway from the Forest Service Road to the proposed
building area, and the leveling of the building area itself. The proposed residence will be
excavated into the hillside, with the entire foundation sited on undisturbed native soil,
mainly the till layer. The yard area in front (to the south) of the residence may be
enlarged by wasting the soils produced from excavating the structures' basement or
foundations. Any fill placed on the property will be placed in compliance with the
County's grading ordinance requirements, which require fill placed on slopes steeper
than 20% , to be place on a level bench excavated for the purpose of providing a stable
area to construct the engineered fill slope on. Fill receiving areas will be cleared of
vegetation, and a level bench, a minimum of 6-feet wide,will be excavated so that the fill
slope may be constructed in uniform 6 to 12"thick"lifts" of fill soil, compacted to 90+%
compaction before subsequent lifts of fill are placed. Fill slopes constructed in this
manner, may be constructed to the County's standard 2:1 (H:V 50%) fill slope
geometry. Excavation on the uphill side of the road, and for the building foundation is
expected to be dug out of the hardpan layer, and may be excavated at a maximum 1:1
slope (H:V).
5. SLOPE STABILITY ANALYSIS:
The steepest slopes on the property in its present condition contain no obvious recent
mass landslides or stability problem indicators. The proposed building area in the central
area of the northerly portion of the property has no discernible irregularities, settlements,
fissures, or evidence of consolidation problems.
Unified Soil Classification System typing places the soils in a coarse grained soil (GM)
classification with a dry density between 120-135 lbm/ft3 and a typical effective stress
friction angle (0)> 34°. The surface soil layers appear to be a relatively dirty gravel, so
a GP soil classification may also be appropriate with the same dry density and phi angle.
A soil density of 130 lbs/ft3 will be used in the stability analysis.
Slope stability calculations are addressed on an Excel spreadsheet following the plans. A
phi angle of 360 for the soil internal friction angle was used along with a cohesion value
of 300 lbs per ft2. The glacial till soils can be modeled with cohesion values as high as
1000 lbs per ft2, and with internal friction angles above 40°, so the analysis is based on
conservative assumptions. Foundations bearing on the medium dense and dense
Hoodsport gravelly sandy loams can expect to realize bearing capacities of the natural
soil in the 1000 to 2000 pounds per square foot range, with settlement for residential
foundations within half an inch overall.
File:C:IProjectslStockinglGeolGeo-Rpt.doc 3 of 5 5/11/2006
TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
6. RECOMMENDED SETBACKS & DRAINAGE:
The property contains only isolated areas of relatively level ground, and will require
construction on what may be classified as potentially unstable ground. No structures should
be planned to be placed on fill material, unless the fill is placed as structural fill under the
supervision of an engineer, or an engineering geologist. So long as the residences' footings
are constructed on the natural glacial till, a building setback from the crest of the slope is not
needed. Footings should be buried on their downslope side enough to protect them from
freeze-thaw actions. For this area (Cushman/Olympic foothills), a minimum 18" of soil cover
should be placed above all footings.
Drainage from the developed property should be directed into the naturally vegetated areas of
the property. Concentrated discharges of collected stormwater runoff should be avoided.
Collected stormwater runoff should be dispersed as close to its source as practical and
allowed to seep into the ground. Sensitive areas like the septic drainfield area should be
protected from the delivery of any stormwater flows in its vicinity. Driveway runoff should
be dispersed as frequently as possible into the surrounding vegetation. Water bars, and
driveway cross culverts on no greater than 200' intervals should be planned as part of the
property development.
Roof runoff may be dispersed at downspout splash blocks, and directed away from the
foundation into the yard area.
7. CLEARING, GRADING,AND VEGETATION MANAGEMENT:
Clearing for the residence, a driveway, and a possible well location will be necessary for
development of the property. Besides removing trees for the building and driveway
footprints, danger trees (potentially threatening to the residence)may be planned to be
removed. Aside from clearing and grading the property for the residence and driveway,no
clearing or grading on other parts of the property is planned.
Once a residence is constructed on the property, bare areas will be planted with grass and
landscape plantings. Overall, it appears the development of the property will have a minor
impact on the property itself, and little or no impact to surrounding properties.
8. EROSION AND SEDIMENT CONTROL:
As indicated earlier in this report,the site's soils are not considered erodible, and minimal
Erosion and Sediment(E&S) Control measures should be adequate to protect neighboring
properties and State waters. Access to the site will be developed off of the Forest Service
Road(private), roughly a mile away from any public roads. Construction of the proposed
driveway will include a driving surface of clean gravel or crushed rock.
The major earthwork will be leveling the house's building location, excavating the footing
trenches, and constructing the driveway. These development areas drain mainly to the
owner's property, and will have approximately 20+-feet of vegetative to pass through before
any runoff exits the property at its normal discharge locations.
File:C:IProjectslStockinglGeolGeo-Rpt.doc 4 of 5 5/11/2006
1 TAHJA ENGINEERING, Inc.
PO Box 235, Hoodsport, WA 98548
(360) 877-9512
The existing and proposed features should provide adequate protection against adverse
stormwater runoff impacts.
9. ON-SITE AND OFF-SITE IMPACTS:
Construction and completion of the proposed improvements are not expected to result in
any adverse on-site, or off-site impacts. The proposed residential development of the
property will not result in adverse impacts to either the subject property or to neighboring
properties.
10 SPECIFICATIONS OF FINAL DEVELOPMENT CONDITIONS:
The completed site will be allowed to return, for the most part,to a naturally vegetated state.
The main ground cover will be lawn and medium height shrubbery.
In the future development of the property, discharging concentrations of collected
Stormwater runoff within 20 feet of a property boundary should be avoided.
Conclusions and Summary;
The residential development of the Stocking property located in the Dow Mountain area
of Lake Cushman does not appear to present any stability problems that cannot be
overcome, and will not result in any undesirable impacts.
The property itself provides an adequate vegetated buffer area to protect neighboring
properties and State Waters from adverse stormwater runoff impacts. The stormwater
related recommendations made in this report should be adequate for both temporary and
permanent stormwater runoff management and concerns.
I hope this report meets the needs of the Stockings, and Mason County in planning the
property's development.
A P
Sincerely, ='4 .
WAS fY
Alan A. Tahja, P.E. �✓'
Attached: Site Plan(Plan Sheets 1 & 2) oNnL '
Cross Section(Plan Sheet 3)
Stability Analysis (Excel Spreadsheet) MMM 11171
File: C:IProjectslStockinglGeolGeo-Rpt.doc 5 of 5 5/11/2006
Revision# Description Date TAHJA ENGINEERING,Inc. STOCKING SITE PLAN
Alan Tabja,P.E. Redfield Stocking Stocking
PO Box 235 9805 Wlritecap Drive NW
Hoodspor4 WA 98548 Olympia, WA 98502 2 of 3
CountyPrcl No. 42333 5103013 (360)877-9512 (360) 339-2705
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Revision# Description Date TAHJA ENGINEERING,Inc. STOCKING SITE PLAN ft.F&
Alan Tabia,P.E. Redfield Stocking Stocking
PO Box 235 9805 Whitecap Drive NW
Hoodspor[; WA 98548 Olympia, WA 98502
County Prcl No. 42333 5103013 (360)877-9512 (360) 339-2705 3 of 3
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Stocking Stability Analysis
Mason County Parcel Number 42333-51-03013
Slope Stability Analysis Section A-A
Weight
Slip Plane Angle: 452 kip
1200 IF
3470 SF
Slip Plane Length=260'
1170
Normal Force 1120
Fri
0+00 0+50 1+00 1+50 2+00 2+50 3+00 3+50 4+00
A.
Factor of Safety(FS) is to be calculated against sliding -Static Conditions
FS = Resisting force/Driving force
_ [c'L+ N'x Tan(())]/[W x sin(a)]
_ [c'L+ (W x cos(a) - U x L)x tan(8)]/[W x sin(a)] 78�
where; c � 'IpNAi.
FS= Factor of Safety against sliding 14XPws: 11/7/2
c' = drained shear strength of the slide plane(c' —300 psf for med dense glacial till
6= angle of internal friction (360 used)
L = Length of slip plane surface (260')
N = normal force : perpendicular to slip plane (N =W x cos(a))
W= total weight of failure wedge (130 pcf x 3470') =451,100 Ibs=452 kip)
u= average pore water pressure along the slip surface (psf) = 0 for gravelly loam sands
a= Slope/Slip Plane Angle (110)
FS = [(.3 x 260)+[452 x cos(11 0)-(0 x 260)]x tan(36)]/[452 x sin(11°)]
_ [(78+(443.7)(0.9816)]/86.2 = 400/86.2 =4.64
4.64 > 1.5 OK
Factor of Safety (FS) against sliding - Dynamic Conditions(Seismic Factor b= 0.3)
FS = [c'L+ (W x cos(a) - b x W x sin(a) - U x L)x tan(6)]/[W x sin(a) + b x W x cos(a)]
"=[(.3x260+(452xcos(1 1°)-.3x452xsin(11 0)-Ox260)xtan(36)]/(452xsin(11)+.3x452xcos11°
_ (78+ (443.7-25.9 -0)x .7265)/[86.2 + 133.1]
= 381.51219.4= 1.74 > 1 OK
TAHJA ENGINEERING, Inc. 5/11/2006
°%.SrATF MASON COUNTY
o°y A o N DEPARTMENT OF COMMUNITY DEVELOPMENT
s N X Planning Division
N Y ti P O Box 279, Shelton, WA 98584
(360)427-9670
1864
REQUEST FOR ADDITIONAL INFORMATION
August 22, 2006
REDFIELD STOCKING
9805 WHITECAP DR NW
OLYM[PIA WA 98502
Parcel No.: 423335103013
Project Description: Redfield Stocking: Approx. 1/2 acres
Dear Applicant:
You have submitted a permit application (case no. FPA2006-00026) for proposed
construction or development in the county. Upon review of your application, I require
additional information to complete the permit review process.
Therefore, review of your application will not proceed until the necessary information
is provided (see the comment section of this letter for details.) Once the information
is submitted and the application is complete, I will continue to process your
application accordingly. If the additional information is not provided to the County
within 180 days of this request, the application shall expire and no further action on
the proposed development shall take place.
Please contact me at (360) 427-9670, ext. 295 if you have questions.
Sinc rely,
Tammi Clark
Land Use Planner
Mason County Planning Department
8/22/2006 Page 1 of 2 FPA2006-00026
REQUEST FOR ADDITIONAL INFORMATION
8/22/2006 Case No.: FPA2006-00026
Comments: I recently received your application for your forest practices application
(FPA). Unfortunately it is incomplete and can not be processed in its
current condition. Below is a list of the item(s) that need more attention
before the application can be deemed complete:
(1) 1 need a site map consistent with the requirements of 11.05.120.A
(enclosed). If you have not done so already please be sure that the
requirements of 11.05.120.13 are also established on the ground.
(2) Please find enclosed a copy of the ESA Listed Salmonids Checklist.
Every SEPA I review must have one of these attached, even if the
conditions it is concerned with don't exist on the site.
In order to keep your case open, please respond within 180-days. If
you have any questions, please contact me at extension 295. Thank
you.
8/22/2006 Page 2 of 2 FPA2006-00026
�oN_srgrFo MASON COUNTY
UP M o y DEPARTMENT OF PUBLIC WORKS
O SU =
r O T a BUILDING 8 415 NORTH SIXTH STREET P.O. BOX 1850
2� NY Y SHELTON, WASHINGTON 98584
OJ �O Phone(360)427-9670 x450
1864 Fax(360)427-7783
September 5, 2006
MASON COUNTY
MISSION RE: SEP2006-00128
The mission of Mason
County Government is to
provide essential& Community Development
mandated services which 426 W Cedar
will preserve & benefit the P.O. Box 279
health,safety,&welfare of Shelton,WA 98584
the general public in a
professional and courteous
manner through the effective Dear Bob,
and equitable management
of available public Road Operations and Maintenance does not have any comments on this proposed
resources. action. This doesn't impact any County maintained road.
Mason County recognizes Thank you,
that its employees&
volunteers are the
foundation upon which Allan Eaton
these services are provided.
Assistant Road Operations and Maintenance Manager
J:\AmyB\Setbacks from planning\SEP's from plan ning\SEP2006-00128.doc
# ES1 BLK 3 LOT 13
TREES TO BE REMOVED
240
108 24
135
® 60
18
11
® ® ® 281
312 60 ® ® ® ® ® ® 28
://
FUTURE CABIN ® LEVEL AREA
DRAIN FIELD EASEMENT
50
WELL SITE
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---30--� EXISTING DRIVEWAY
EXISTING LEVEL
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Storm water Issues.txt
Storm water runoff issues for ES1, Block 3, Lot 13
Lake Cushman Dow Mountain Area
During and after the togging and clearing of the above property
I will be using straw bale barriers and or silt fences at any areas
that could allow storm water into ditches or onto access roads. The area
being partially cleared is on the upper portion of the five acre lot which
is 240 ft x 935 ft deep. Any storm water runoff will first have to pass
thru the undisturbed upper portion of the property then would have to
go down slope onto the undisturbed 600 ft. of the lower section of the
property. That area is heavily forrested and covered with thick vegetation,
and will not be developed in any way. There will be minimum 15 ft. wide, with
most areas 30 to 40 ft. , (from property line) undisturbed buffer areas on both
sides of the project as well .
Any cleared areas except the driveway will be replanted with grass as
soon as possible after clearing. The driveway will be covered with crushed
rock with small cross ditches to divert water to the sides and into the
vegetation areas.
Redfield Stocking
9805 whitecap Dr. NW
Olympia, wa. 98502
360-339-2705
EC dV ®
gob �� 205
�D #- 4?-33S 51 b 3 G/ 426 \q. CEDO- ST:'
Page 1
Storm water Issues.txt
Storm water runoff issues for Es1, Block 3, Lot 13
Lake Cushman Dow Mountain Area
During and after the logging and clearing of the above property
I will be using straw bale barriers and or silt fences at any areas
that could allow storm water into ditches or onto access roads. The area
being partially cleared is on the upper portion of the five acre lot which
is 240 f t deep.eep. Any storm water runoff will first have to pass
thru the undisturbed upper portion of the property then would have to
go down slope onto the undisturbed 600 ft. of the lower section of the
property. That area is heavily forrested and covered with thick vegetation,
and will not be developed in any way. There will be minimum 15 ft. wide, with
most areas 30 to 40 ft. , (from property line) undisturbed buffer areas on both
sides of the project as well .
Any cleared areas except the driveway will be replanted with grass as
soon as possible after clearing. The driveway will be covered with crushed
rock with small cross ditches to divert water to the sides and into the
vegetation areas.
Redfield stocking
9805 whitecap Dr. NW
Olympia, Wa. 98502
360-339-2705
RECEIVED
r C
t9N — �2333 "1 03 G/ 3 426 ��. C AR sr!
Page 1
4
240
108 24- LOGGING LANDING
THIS AREA
1190
ALL TREES TO BE REMOVED
BPS MARKED W/PINK RIBBON, 1180
ALL ❑UTSIDE AREAS FOR
TREE/VEGETATION RETENSION,
135
60
18 1170
11 ® ® ® ® ® ® 1160
935 312 ® ®® ® ® 281
60 ® ® ® 28
® ® 19% SLOPE
® ® ® ® ® ® ® ® 1150
25-30% SL❑PE
FUTURE CABIN I v
® LEVEL AREA
® ® 1140
® ® ® ® ® ®
® ® ® ® ® ® ® ® 1130
CULVERT "
DRAIN FIELD (FORREST SERVICE ROAD 2300)
EASEMENT
1120
® 1110
50
1100
WELL SITE
EXISTING DRIVEWAY
EXISTING LEVEL 30--- TO LOT 14
AREA
3
42% SLOPE 0% SL❑PE
I
ES1 BLK 3 LOT 13
LALEt 1' = 50' SITE PLAN
50