PZ - Preliminary Engineering Report Package ailey Engineering,Inc.
CIVIL ENGINEERINGIPLANNINGICADD
Preliminary Engineering Report
For
Blayden Subdivision
Meridian, Idaho
SEWER/WATER
IRRIGATION
STORM DRAINAGE
�S\ONAL S 0
�G\STE"? �F PROJECT NO: C2020-009
F
Q� 01/25/2023�
`P<�1 882 DATE: 10/12/2021
.6� REVISED: 01/25/2023
OFG�C1`
S C�P�� DEVELOPER
Shawn Brownlee
Trilogy Development, Inc.
9839 W. Cable Car St.,
Suite 101
Boise, ID 83709
(208) 895-8858
1119 E. State St., Suite 210 ♦ Eagle, Idaho 83616 ♦ Tel.: 208-938-0013
• The proposed subdivision is located in Meridian,Idaho. The project site is 24.98 acres and
will be subdivided into approximately 11 common lots with 3 parking/drive lots. There will
also be 28 buildable lots,which consist of 1 apartment lot,22 townhouse lots,and 15
commercial lots. There will also be 1 existing home that will remain.
Sewer
• Preliminary sewer profiles are included in the preliminary plat.
• There is an existing sewer main in Black Cat that will be connected to and used to serve a
majority of the site. It is believed the existing line in Black Cat is 12",however,City utility
maps will confirm this.
• The western region of the site will tie into the proposed Prescott Ridge Subdivision to the
west. Mainline sizing to be confirmed.
• Internal gravity sewer lines will be 8"diameter unless otherwise required by the City.
Water
• There is an existing 12"water main Black Cat that will be tapped to serve the site.
• Internal lines will be 8"unless otherwise required by the City.
• A secondary water connection may need to be provided pending city water modeling.
Depending on timing, a second connection may be able to be provided through the proposed
Prescott Ridge Subdivision to the west.
Flood Hazard
• The site is not in a flood hazard zone,reference FIRM Panel 16001 C0140J, effective
06/19/2020.
Gravity Irrigation
• There is a concrete ditch that enters the site in the center of the southern project boundary.
This concrete ditch is used to water the Blayden property and flows west before discharging to
an existing ditch that flows north through the site. The existing ditch flowing north enters the
site in the southwest corner and flows north,entering a box near the north boundary.Water
then turns east and flows for about 200'before entering an existing box(Box 1)and flowing
north,leaving the site. Box 1 is also fed from an existing pipe from the east. This eastern pipe
is fed from a field drain within the Blayden property(to be removed)as well as an existing
pipe that enters the site in the northeast corner(to be protected).
• There is a 2nd delivery to the site off Black Cat in the north corner of the site. This water will
be combined with the other delivery noted above and piped through the site.
• Preliminary gravity irrigation piping is shown on the plans.
• Site visit and irrigation district to confirm deliveries/drainages noted above.
Pressurized Irrigation
• A private irrigation pump station will need to be constructed for this subdivision. The
development is within Settlers Irrigation District and receives water out of the McMullen
Canal and an unnamed ditch that parallels Black Cat Rd.
• Irrigation district to confirm delivery timing/measurements.
• Irrigation district to confirm available water rights.
Grading & Drainage:
• Geotechnical report from Allwest, dated 11/04/2020,has been received. The report
recommends an infiltration rate of 8"/hr.
• Groundwater monitoring has been occurring monthly since August 2020 and has been
routinely observed as shallow as approximately 8-10' deep. See attached latest
groundwater monitoring.
• Preliminary calculations are attached. Shallow seepage beds have been preliminarily
designed throughout the site.
• Pervious concrete seepage beds have been preliminarily designed in the private pathways
between multi-family residences.
• Tentative subsurface seepage beds have been designed but are subject to change based on
site grading and ADA accessibility constraints.
o Pervious concrete may be utilized in lieu of the beds if a flatter grading profile is
necessary.
Attachments:
1. IDF Curve&Preliminary Drainage Calculations
2. Preliminary Drainage Map
3. Geotechnical Report& Groundwater Monitoring
4. FEMA FIRM Panel
Blayden Subdivision - Preliminary Drainage Calculations (Seepage Beds)
Updated: 1/25/2023
ACHD Runoff Calcs ACHD Seepage Bed Design
Runoff Time of 100-Yr
Drainage Area Area sf Area(acres) Coefficient Concentration Intensity 100 cfs ft)V100(cu ft) Common Lot? Req.V ) (in/hr)Infiltration Rate
(cu Void Ratio Depth(ft) Width(ft) Required Length
Est min in hr
DA 1 38810 0.891 0.90 10 0.69 0.55 Seepage Bed 1 2771 no 3464 0.40 8.0 5 15 116
DA 2 17812 0.409 0.90 10 0.69 0.25 Seepage Bed 2 1272 no 1590 0.40 8.0 5 15 53
DA 3 34784 0.799 0.85 10 0.69 0.47 Seepage Bed 3 2346 yes 2346 0.40 8.0 5 15 79
DA 4 12688 0.291 0.90 10 0.69 0.18 Seepage Bed 4 906 no 1132 0.40 8.0 5 15 38
DA 5 84840 1.948 0.90 10 0.69 1.21 Seepage Bed 5 6058 yes 6058 0.40 8.0 5 30 101
DA 6 34563 0.793 0.85 10 0.69 0.47 Seepage Bed 6 2331 no 2914 0.40 8.0 5 15 98
DA 7 15698 0.360 0.60 10 0.69 0.15 Seepage Bed 7 747 no 934 0.40 8.0 5 9 52
DA 8 14075 0.323 0.80 10 0.69 0.18 Seepage Bed 8 893 yes 893 0.40 8.0 5 15 30
DA 9 92203 2.117 0.75 10 0.69 1.10 Seepage Bed 9 5486 yes 5486 0.40 8.0 5 15 183
DA 10 16736 0.384 0.85 10 0.69 0.23 Seepage Bed 10 1129 yes 1129 0.40 1 8.0 5 15 38
DA 11 36340 0.834 0.95 10 0.69 0.55 Seepage Bed 11 2739 yes 2739 0.40 8.0 5 15 92
DA 12 40790 0.936 0.95 10 0.69 0.61 Seepage Bed 12 3074 yes 3074 0.40 8.0 5 15 103
DA 13 39910 0.916 0.95 10 0.69 0.60 Seepage Bed 13 3008 yes 3008 0.40 8.0 5 15 101
DA 14 42692 0.980 0.95 10 0.69 0.64 Seepage Bed 14 3218 yes 3218 0.40 8.0 5 15 108
DA 15 27165 0.624 0.95 10 0.69 0.41 Seepage Bed 15 2047 yes 2047 0.40 8.0 5 15 69
DA 16 26249 0.603 0.95 10 0.69 0.40 Seepage Bed 16 1978 yes 1978 0.40 8.0 5 15 66
DA 17 38476 0.883 0.95 10 0.69 0.58 Seepage Bed 17 2900 yes 2900 0.40 8.0 5 15 97
DA 18 38482 0.883 0.95 10 0.69 0.58 Seepage Bed 18 2900 yes 2900 0.40 8.0 5 15 97
DA 19 38572 0.885 0.95 10 0.69 0.58 Seepage Bed 19 2907 yes 2907 0.40 8.0 5 15 97
DA 20 37933 0.871 0.95 10 0.69 0.57 Seepage Bed 20 2859 yes 2859 0.40 8.0 5 15 96
DA 21 46256 1.062 0.95 10 0.69 0.70 Seepage Bed 21 3486 yes 3486 0.40 8.0 5 15 117
1000 Gal SG Trap:3.33 cfs max Seepage beds will drain in<48 hrs pending infiltration rate is equal to or greater than 1 in/hr.If infiltration is lower it will govern design if standard
1500 Gal SG Trap:4.16 cfs max
ACHD IDF,with revised curves
Tc 100-Year 25-Year
10 2.58 1.85
15 2.18 1.56
20 1.81 1.30
25 1.58 1.14
30 1.51 1.08
35 1.25 0.90
40 1.15 0.82
45 1.07 0.77
50 1.00 0.72
55 0.96 0.69
60 1 0.96 1 0.69
Blayden Subdivision-Preliminary Drainage Calculations(Pervious Concrete Seepage Beds)
Updated 1/25/2023
ACHD Runoff Calcs ACHD Seeoaee Bed Design
Runoff
Drainage Area Areas Area Coefficient Time of Concentration(min) 100-Vr Intensity 00 ids VI00(cu ft) Common Lot? Req.VI00(cu Void Ratio Infiltration Rate(in/hr) Depth(ft) Width(ft) Required Length(if
acres Es[ im/hrl ft) within Common Lot)
DA P-1 27489 0.631 0.85 20 1.81 0.97 Pervious Bed 1 1854 yes 1854 0.40 8.0 3 6 258
DA P-2 27498 0.631 0.85 20 1.81 0.97 Pervious Bed 2 1854 yes 1854 0.40 8.0 3 6 258
DA P-3 27507 0.631 0.85 20 1.81 0.97 Pervious Bed 3 1855 yes 1855 0.40 8.0 3 6 258
DA P-4 26977 0.619 0.85 20 1.81 0.95 Pervious Bed 4 1819 yes 1819 0.40 8.0 3 6 253
1000 Gal SG Trap:3.33 cfs max Seepage beds will drain in<48 hm din filtration rate is equal to or ter than 1 in/hr.If infiltration is lower it will des( if standard dimensions are utilized.
1500 Gal SG Trap:4.16 cis max pending qua grea govern design
ACHD IDF,with revised curves
Tc 100-Year 25-Year
10 2.58 1.85 Drainage Subbasins to be determined with final site design
15 2.18 1.56
20 1.81 1.30
25 1.58 1.14
30 1.51 1.08
35 1.25 0.90
40 1.15 0.82
45 1.07 0.77
50 1.00 0.72
55 0.% 0..
60 0.96 0.69
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.......... PROJECT:
SCALE IN FEET C2020-009
1"=80' SHEET
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TECH
ONMENTAL
ALLWEST MATERIALS OTESTING I SPECIAL IR SPECTION
AN EMPLOYEE-OWNED COMPANY
November 4, 2020
Shawn Brownlee
Trilogy Development
9839 West Cable Car Street, Suite 101
Boise, Idaho 83709
Lhawn�,-:- igyidaho.com
RE: Geotechnical Evaluation
Black Cat and Chinden Development
Ada County, Idaho
ALLWEST Project No. 520-252G
Mr. Brownlee:
ALLWEST has completed the authorized geotechnical evaluation for the proposed Black
Cat and Chinden Development to be located near the southwest corner of Black Cat Road
and Highway 20/26 (Chinden Boulevard) in Ada County just northwest of Meridian, Idaho.
The purpose of this evaluation was to characterize subsurface soil conditions at the site and
provide geotechnical recommendations to assist planning, design, and construction of the
proposed development. Based on our evaluation, the site is suitable for the planned
development. The attached report presents the results of our field evaluation, laboratory
testing, and our recommendations.
We appreciate the opportunity to be of service to Trilogy Development. If you have any
questions or need additional information, please contact us at (208) 895-7898.
Sincerely,
ALLWEST KU
Adrian Mascorro, P.E.
Area Manager
255 N. Linder Rd., Suite#100, Meridian, ID 83642
Phone: 208.895.7898• Fax: 208.898.3959
Hayden, ID• Lewiston, ID•Meridian, ID•Spokane Valley,WA•Missoula, MT
www.allwesttesting.com
GEOTECHNICAL EVALUATION
BLACK CAT AND CHINDEN DEVELOPMENT
ADA COUNTY, IDAHO
ALLWEST PROJECT NO. 520-252G
November 4, 2020
Prepared for:
Trilogy Development
9839 West Cable Car Street, Suite 101
Nampa, Idaho 83709
Prepared By:
ALLWEST
255 North Linder Road, Suite 100
Meridian, Idaho 83642
ALLWEST
WWW.ALLWESTTESTING.COM
TABLE OF CONTENTS
ALLWEST Project No. 520-252G
Black Cat and Chinden Development
Meridian, Idaho
Page
1.0 SCOPE OF SERVICES ........................................................................................2
2.0 PROJECT UNDERSTANDING.............................................................................3
3.0 FIELD EVALUATION PROCEDURES.................................................................3
4.0 SITE CONDITIONS ..............................................................................................3
4.1 General Geologic Conditions............................................................................. 3
4.2 General Soil Conditions..................................................................................... 3
5.0 EXPLORATION AND SAMPLING .......................................................................4
5.1 Subsurface Soil Conditions ...............................................................................4
5.2 Subsurface Water.............................................................................................. 5
6.0 LABORATORY TESTING ....................................................................................5
7.0 CONCLUSIONS AND RECOMMENDATIONS ....................................................5
7.1 Grading ............................................................................................................. 6
7.2 Site Preparation.................................................................................................6
7.3 Subgrade Stabilization ...................................................................................... 7
7.4 Excavation......................................................................................................... 8
7.5 Materials............................................................................................................ 8
7.6 Fill Placement and Compaction......................................................................... 9
7.7 Utility Trenches.................................................................................................. 9
7.8 Wet Weather Construction ................................................................................ 9
7.9 Cold Weather Construction ............................................................................. 10
7.10 Stormwater Disposal ..................................................................................... 10
7.11 Asphalt Pavements ....................................................................................... 11
8.0 ADDITIONAL RECOMMENDED SERVICES..................................................... 12
9.0 EVALUATION LIMITATIONS............................................................................. 13
Appendix A— Site Vicinity Map, Exploration Location Plan
Appendix B —Test Pit Logs, Unified Soil Classification System
Appendix C— Laboratory Test Results
GEOTECHNICAL I ENVIRONMENTAL
ALLWESTMATERIALS TESTING I SPECIAL INSPECTION
AN EMPLOYEE-OWNED COMPANY
Geotechnical Evaluation
Black Cat and Chinden Development
Ada County, Idaho
ALLWEST has completed the geotechnical evaluation for the proposed Black Cat and
Chinden Development to be located near the southwest corner of Black Cat Road and
Highway 20/26 (Chinden Boulevard) in Ada County northeast of Meridian, Idaho. The
general location of the site is shown on Figure A-1 — Site Vicinity Map in Appendix A
of this report. The purpose of this evaluation was to identify subsurface soil conditions
at the site, and provide opinions and recommendations for the proposed development,
relative to earthwork, stormwater disposal, and pavement section design. This report
details the results of our field evaluation and presents recommendations to assist
planning, design, and construction.
1.0 SCOPE OF SERVICES
Our scope of services for the project included the following:
1) Prior to subsurface exploration, we visited the site to observe site accessibility
and to pre-mark exploration locations, as required by Idaho Digline.
2) Notified Idaho Digline to locate on-site utilities, as required by Idaho state law.
3) Subcontracted a backhoe and operator to observe the excavation of 13 test pits
throughout the site to a maximum depth of 13 feet.
4) Visually described, classified, and logged the soils encountered within test pits
in general accordance with ASTM D 2487 and ASTM D 2488, which utilizes the
Unified Soil Classification System (USCS), and we logged the subsurface
profiles. We obtained disturbed soil samples within select test pits.
5) Performed seepage tests within select test pits to evaluate subsurface seepage.
We installed PVC pipes within select test pits throughout the site for future
groundwater monitoring.
6) At completion of exploration, the test pits were loosely backfilled with excavated
soil approximately level with the ground surface.
7) Performed laboratory tests on select soil samples to assess some of the soil
engineering properties and characteristics.
8) Reviewed the results of the field evaluation and laboratory testing, performed
engineering analyses, and provided recommendations to assist project
planning, design, and construction.
9) Prepared this report with our field evaluation results, subsurface logs, and
geotechnical-related opinions and recommendations.
We provided our services for the project in general accordance with our geotechnical
proposal (520-252P) dated June 3, 2020.
GEOTECHNICAL I ENVIRONMENTAL
ALLWESTMATERIALS TESTING I SPECIAL INSPECTION
AN EMPLOYEE-OWNED COMPANY
Geotechnical Evaluation ALLWEST Project No. 520-252G
Black Cat and Chinden Development Page 3
Ada County, Idaho
2.0 PROJECT UNDERSTANDING
Based on review of an aerial image of the project and site boundary delineation of the
parcels on a LandproDATA image, we understand the project consists of an
approximate 26-acre residential subdivision development. As with typical subdivision
developments, we anticipate the development will include associated infrastructure,
stormwater disposal facilities, and asphalt-paved roadways.
At the time of our exploration, four existing residences with variable associated
outbuildings existed throughout the overall site. We assume these existing
buildings/structures and associated infrastructure will be demolished as part of the
development. We did not review development or grading plans, but we anticipate cut
and fill for the site to be approximately 2 feet or less.
3.0 FIELD EVALUATION PROCEDURES
To complete this evaluation, we observed the excavation of 13 test pits on June 18,
2020. We obtained select soil samples for further identification and laboratory testing,
and we performed field seepage testing within select test pits to help evaluate
subsurface soil seepage. Approximate test pit locations are shown on Figure A-2 —
Exploration Location Plan in Appendix A.
4.0 SITE CONDITIONS
At the time of exploration, the site consisted of multiple parcels that were actively being
farmed, and the overall site contained four existing residences with variable associated
outbuildings. The overall site is bordered by farmland in all directions, with a mix of
private residential area and farmland to the south and southeast. Highway 20/26
(Chinden Boulevard) borders part of the site to the north, and Black Cat Road borders
majority of the site to the east.
4.1 General Geologic Conditions
The geologic conditions at the site are mapped as Gravel of Whitney Terrace (Qwg)
on the "Geologic Map of the Boise Valley and Adjoining Area, Western Snake River
Plain, Idaho" (by Othberg and Stanford, 1992). Soils consist of sandy pebbles and
cobble gravels between 16 to 80 feet in thickness, and mantled with 3 to 6 feet of loess.
The soils encountered within test pits are generally consistent with geologic mapping.
4.2 General Soil Conditions
The USDA Natural Resources Conservation Service (NRCS), which represents the
upper 5 feet of soil profile, has mapped the soils on the site as Power silt loam and
Purdam silt loam. The parent materials are mixed alluvium, lacustrine deposits, and/or
GEOTECHNICAL I ENVIRONMENTAL
ALLWESTMATERIALS TESTING I SPECIAL INSPECTION
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Geotechnical Evaluation ALLWEST Project No. 520-252G
Black Cat and Chinden Development Page 4
Ada County, Idaho
loess, consisting of silty clay loam, silty loam, cemented material, stratified sand to
loam, fine sandy loam, and para-gravelly silt loam.
The soils encountered within test pits are generally consistent with NRCS mapping.
5.0 EXPLORATION AND SAMPLING
We observed the excavation of test pits using a Case 580C backhoe with a 3-foot-wide
bucket. We obtained Google Earth latitude and longitude coordinates of test pit
locations with a hand-held cellular device. These coordinates can be found on
individual test pit logs in the Appendix B and should be considered accurate to the
degree implied by the method used.
We visually described, classified, and logged soil conditions observed within test pits
and we obtained disturbed soil samples from exploration locations. We performed
seepage testing within select test pits throughout the site. At completion of exploration,
we installed slotted PVC pipes within 9 test pits, and the test pits observed were loosely
backfilled with excavated soils approximately level with existing ground surfaces. The
test pit locations were identified on-site with flagged stakes and/or white PVC pipes.
5.1 Subsurface Soil Conditions
The site contained approximately 6 inches of surficial roots and vegetation at the
ground surface. Where trees are encountered, large roots may be encountered
between 2 and 4 feet below ground. In general, the subsurface soils within the
observed test pits consisted of surficial native clays, underlain by silts and silty sands
(with varying induration/cementation), overlying gravels with sand (to the maximum
exploration depths of up 13 feet).
Specific descriptions of soils observed throughout our field exploration follow:
Lean clay (CL) (native) — At the ground surface, except within test pit TP-10, we
observed native lean clay down to depths of 1 to 3 feet below ground. We described
lean clay as light brown, stiff, and moist.
Silt (ML), silt with sand (ML), sandy silt (ML) — Underlying lean clay, and at the ground
surface within TP-10, we observed native silt, silt with sand, or sandy silt down to
depths of 1 to 6 feet below ground. We described silty soils as tan, medium dense,
and moist. We observed weak to strong induration/cementation withing test pits TP-11
and TP-13.
Silty-clay with sand (CL-ML) — Underlying silt with sand in test pit TP-4, we observed
a layer of silty-clay with sand down to a depth of 8'/2 feet. We described silty-clay with
sand as light brown, stiff, and moist.
GEOTECHNICAL I ENVIRONMENTAL
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Geotechnical Evaluation ALLWEST Project No. 520-252G
Black Cat and Chinden Development Page 5
Ada County, Idaho
Silty sand (SM) — Underlying silty soils, except within test pits TP-2, -4, and -13, we
observed silty sand down to depths of 3 to 10 feet. We described silty sand as tan,
medium dense to dense, and moist. The silty sand soils contained varying amounts
and thicknesses of weak to strong induration and cementation.
Poorly-qraded gravel (GP), poorly-qraded gravel with silt and sand (GP-GM) —
Underlying silty soils or silty sands, we observed poorly-graded gravel with silt and
sand overlying poorly-graded gravel with sand down to maximum test pit termination
depths of up to 13 feet. We described gravel soils as tan, medium dense, and moist.
Detailed soil descriptions, depths and notes are presented on individual test pit logs in
Appendix B. The descriptive soil terms used on the test pit logs in this report, can be
referenced by the USCS. A copy of the USCS is included in Appendix B. Subsurface
conditions may vary between exploration locations. Such changes in subsurface
conditions may not be apparent until construction, and if they change significantly from
those observed, then accordingly, construction timing, plans, and costs may change.
5.2 Subsurface Water
At the time of exploration, we did not encounter groundwater within test pits down to a
maximum depth of 13 feet. Groundwater in the area is typically influenced by local
irrigation and nearby canals, drains, and laterals. Groundwater may also be influenced
by precipitation, on-site construction, and development to adjacent sites. Subsurface
water will fluctuate throughout the different seasons of the year, but will most likely be
affected during seasonal snow melt and irrigation seasons (March to October).
We installed PVC pipes within 9 test pits throughout the site for future groundwater
monitoring. If authorized to perform groundwater monitoring, ALLWEST can verify the
presence (or absence) of groundwater throughout irrigation and snowmelt seasons.
6.0 LABORATORY TESTING
We performed laboratory testing to supplement field classifications and to assess
some of the soil engineering properties and parameters. The laboratory tests
conducted included moisture content (ASTM D 2216), gradation (ASTM D 1140),
Atterberg limits (ASTM D 4318), and California bearing ratio (CBR) (ASTM D 1883).
Laboratory test results are summarized in Appendix C, and are also presented on test
pit logs in Appendix B.
7.0 CONCLUSIONS AND RECOMMENDATIONS
Based on our observations, testing and evaluation, in our opinion the site is suitable
for the planned residential development, provided our recommendations are adhered
to. The following recommendations are presented to assist with planning, design, and
construction of the development, relative to earthwork, infrastructure, stormwater
disposal, and asphalt pavements.
GEOTECHNICAL I ENVIRONMENTAL
ALLWESTMATERIALS TESTING I SPECIAL INSPECTION
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Geotechnical Evaluation ALLWEST Project No. 520-252G
Black Cat and Chinden Development Page 6
Ada County, Idaho
These recommendations are based on our understanding of the proposed
development, the conditions observed within exploration locations, laboratory test
results, and engineering analysis. If the scope of construction changes, or if conditions
are encountered during construction that differ from those described herein, we should
be notified so we can review our recommendations and provide revisions, if necessary.
Foundation-related recommendations are not provided as part of this evaluation.
7.1 Grading
We did not review final grading plans for this development, but we anticipate site
grading will consist of cuts and fills of up to 2 feet. We should be notified if actual site
grading varies significantly from this stated information, as it may affect our
recommendations herein.
7.2 Site Preparation
• Prior to conducting site grading, surficial soil containing vegetation, roots and
organics should be removed below proposed site grading fill areas, pavements
areas, and any other development areas. In general, we anticipate
approximately 6 inches of site stripping will be required for majority of the site to
remove surficial vegetation and roots.
• Where trees are encountered and will be removed as part of the development,
large root systems should be completely over-excavated and replaced with
suitable fill soils. Tree roots depths will not fully be known until construction, but
we anticipate a minimum of 2 to 4 feet of over-excavation will be required to
remove tree roots.
• Where existing structures, outbuildings, and infrastructure are located that will
be demolished as part of this development, complete over-excavation is
required down to native soils, and these over-excavated areas must be replaced
with suitably moisture-conditioned and compacted fill soils. This includes any
existing drain field areas or other previously placed fill areas. Lateral limits of
existing infrastructure will not fully be known until construction, and as such, the
earthwork contractor should have contingencies in-place to ensure these areas
are fully over-excavated within future development areas.
• Loose test pit backfill will settle with time, so where any test pits are located
below proposed structures or any development areas, the loose test pit backfill
soil must be re-excavated its entire depth and replaced with suitably moisture-
conditioned and compacted fill soil. Existing over-excavated soils can be reused
to backfill the test pits, provided the soils are not overly saturated, and they can
achieve the required compaction criteria (as required in section 7.6 Fill
Placement and Compaction). We recommend test pit areas be accurately
surveyed so that they may be located and remediated, prior to earthwork
construction and development.
GEOTECHNICAL I ENVIRONMENTAL
ALLWESTMATERIALS TESTING I SPECIAL INSPECTION
AN EMPLOYEE-OWNED COMPANY
Geotechnical Evaluation ALLWEST Project No. 520-252G
Black Cat and Chinden Development Page 7
Ada County, Idaho
• After site stripping, any over-excavations, loose test pit remediation, and prior
to site grading, utility backfill, or roadway construction, the exposed subgrades
should be proof-rolled with a minimum of 5-ton vibratory roller, or with a vibratory
hoe-pack, to confirm subgrade stability. This will also assist in identifying any
soil associated with loose test pit backfills or wet/soft soils due to precipitation.
If native subgrade soil is observed to significantly deflect or pump, it should be
over-excavated and replaced with properly compacted fills, or stabilized to firm,
non-yielding soil as recommended in section 7.3 Subgrade Stabilization.
7.3 Subgrade Stabilization
If the subgrade soils are observed to pump or deflect significantly during grading, the
subgrades should be stabilized prior to fill placement. Subgrades may be stabilized
using geosynthetic reinforcement in conjunction with imported granular structural fill.
The required thicknesses of granular structural fill (used in conjunction with
geosynthetic reinforcement)will be dependent on the construction traffic loading, which
is unknown at this time. Therefore, a certain degree of trial and error may be required
during construction to verify recommended stabilization section thicknesses.
Geosynthetic reinforcement should consist of Tensar TX-160 or equivalent.
Alternatives to Tensar TX-160 must be approved by the geotechnical engineer prior to
use on site. The following recommendations are provided for subgrade stabilization
using geosynthetic reinforcement.
• Geosynthetic reinforcement materials should be placed on a non-disturbed
subgrade with smooth surface. Loose and disturbed soil should be removed
prior to placement of geosynthetic reinforcement materials.
• A minimum weight 4-ounce, non-woven filter fabric should be placed on the
undisturbed subgrade. The geosynthetic reinforcement should be placed
directly on top of the filter fabric. The filter fabric and geosynthetic reinforcement
should be unrolled in the primary direction of fill placement and should be over-
lapped at least 3 feet.
• The geosynthetic materials should be pulled taut to remove slack.
• Construction equipment should not be operated directly on the geosynthetic
materials. Fill should be placed from outside the excavation to create a pad to
operate equipment on. We recommend a minimum of 12 to 18 inches of
granular structural fill be placed over the geosynthetic reinforcement before
operating construction equipment on the fill. Low pressure, track-mounted
equipment should be used to place fill over the geosynthetic reinforcement.
• Granular structural fill placed directly over geosynthetic reinforcement should be
properly moisture-conditioned prior to placement, and once placed, be statically
rolled. This section is the "bridge" section over soft subgrades.
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• After the first "bridge" lift has been placed, the remaining fill material above the
"bridge" section should be compacted to structural fill criteria in section 7.6 Fill
Placement and Compaction, utilizing vibratory compaction methods.
• Vibration should be discontinued if it reduces the subgrade stability. If
compaction criterion is not met within the fill lift above the "bridge" section, the
"bridge" section thickness is not enough, and subgrade stabilization must be
attempted again with a greater "bridge" section.
The geotechnical engineer or a representative of the geotechnical engineer must be
on-site during subgrade stabilization to verify our recommendations are followed, and
to provide additional recommendations, as needed.
7.4 Excavation
Excavation of on-site soil can be accomplished with typical excavation equipment. We
recommend excavations greater than 4 feet deep be sloped no steeper than 1.5HAV
(horizontal to vertical). Alternatively, deeper excavations may be shored or braced in
accordance with Occupational Safety and Health Administration (OSHA) specifications
and local codes. Regarding trench wall support, the site soil is considered Type C soil
according to OSHA guidelines. Ultimately, the contractor is responsible for site safety,
excavation configurations and following OSHA guidelines
7.5 Materials
Stripped soils and soils containing vegetation or debris are only suitable for use in non-
structural landscape areas. Existing on-site soils may be reused as site grading fill,
provided they are stockpiled separately, they meet the criteria below, and they are
compacted as required in this report. Imported granular soils should be free of
organics, debris and other deleterious material and meet the following criteria. Import
materials should be approved by ALLWEST prior to delivery to the site.
Fill Type Criteria
Site Grading Fill Maximum size <_ 6 inches; o 0
Retained on /4 inch sieve < 30/o; Liquid limit < 50/o
Maximum size <_ 6 inches;
Granular Structural Fill, Retained on 3/4-inch sieve < 30%;
Granular Subbase Passing No. 200 sieve <_ 15%; Non-plastic
Alternatively, meet ISPWC section 801 6 inches
Maximum size <_ 1 inch;
Crushed Base Course Retained on 3/4-inch sieve < 10%;
Passing No. 200 sieve < 10%; Non-plastic
Alternatively, meet ISPWC section 802 (Type 1)
Maximum size <_ 2 inches;
Utility Trench Backfill Retained on 3/4-inch sieve <030%;
Passing No. 200 sieve <_ 10/o; Non-plastic
Alternatively, meet ISPWC section 305 (Type I
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7.6 Fill Placement and Compaction
Fill should be placed in lift thicknesses which are appropriate for the compaction
equipment used. Typically, 8- to 12-inch-thick loose-lifts are appropriate for typical
rubber-tire and steel-drum compaction equipment. Lift thicknesses should be reduced
to 4 inches for hand-operated compaction equipment. Fill should be moisture-
conditioned to within 2% of the optimum moisture content prior to placement to facilitate
compaction. Fill should be compacted to the following percentages of the maximum
dry density as determined by ASTM D 1557 (modified Proctor).
For roadway and utility trench construction only, the local governing jurisdiction may
provide their own method of determining the maximum dry density and compaction
requirements (including subgrade).
Fill Area T (0
Compaction
Sub grade Proof-roll' 2
Site Grading Fill / Granular Structural Fill / Pavements 95
Granular Subbase/ Crushed Base Course 952
Utility Trench Backfill 922
'Proof-roll should be observed and approved by a representative of the geotechnical engineer.
2For roadway and utility trench construction only, the local governing jurisdiction may provide their own
method of determining the maximum dry density and compaction requirements (including subgrade).
7.7 Utility Trenches
Support soils for underground utilities will most likely consist of clays, silts, and silty
sands. These soils should provide adequate support for utilities, provided utility
subgrades are compacted utilizing vibratory methods, such as with a large vibratory
hoe-pack. If utility pipe subgrades are soft, yielding, and/or saturated at the time of
construction, subgrade over-excavation and replacement with competent structural fill
may be required below utilities. If support soils yield and/or are saturated at the time of
construction, we should be notified to observe these soils and provide additional
recommendations, as necessary.
We strongly recommend backfilling trench excavations with fill soils which meet criteria
in section 7.5 Materials, as on-site fine-grained soils (silts and clays) may be difficult to
moisture-condition and compact in utility trenches.
7.8 Wet Weather Construction
We recommend earthwork for this site be scheduled for the drier seasons of the year.
If construction is undertaken in wet periods of the year, it will be important to slope the
ground surface to provide drainage away from construction. If construction occurs
during or immediately after excessive precipitation, it may be necessary to over-
excavate and replace saturated subgrade soil, which might otherwise be suitable.
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The on-site soils are sensitive to disturbance when wet. If these soils become wet and
unstable, we recommend construction traffic is minimized where these soils are
exposed. Low ground-pressure (tracked) equipment should be used to minimize
disturbance. Soft and disturbed subgrade areas should be excavated to undisturbed
soil and backfilled with structural fill.
In addition, it should be noted the on-site soils tend to have notable adhesion when
wet and may be easily transported off-site by construction traffic.
7.9 Cold Weather Construction
The on-site soils are frost susceptible. If site grading and construction are anticipated
during cold weather, we recommend good winter construction practices be observed.
Snow and ice should be removed from excavated and fill areas prior to additional
earthwork or construction. Pavement and flatwork portions of the construction should
not be placed on frozen ground; nor should the supporting soils be permitted to freeze
during or after construction. Frozen soils must not be used as fill.
If native subgrades, or suitably moisture-conditioned and compacted fill lifts, will be left
exposed to freezing temperatures overnight, those areas should be protected with a
minimum of 12 inches of loose soil, or covered with heated construction blankets, so
construction subgrades do not freeze. Any frozen soils should be removed prior to
additional fill placement or construction of any kind.
Earthwork construction during cold inclement weather will require a higher level of
attention and detail to achieve required earthwork construction and compaction criteria
and may lead to additional earthwork requirements and extended construction
schedules.
7.10 Stormwater Disposal
During our field investigation we performed field seepage testing within test pits TP-2,
-6, -10, -11, and -13, within poorly-graded gravel with sand soils, where we obtained
field-measured seepage rates of greater than 15 inches per hour (in/hr) within poorly-
graded gravel with silt and sand, and greater than 30 in/hr within poorly-graded gravel
with sand.
Due to variability of calcium carbonate cementation and/or induration observed within
silty and silty sand soils, we do not recommend stormwater disposal be accomplished
within silty or silty sand soils on-site, due to poor and inconsistent soil seepage. Refer
to test pit logs in Appendix B to verify depths and contacts of calcium carbonate
cemented and indurated silty and silty sand soils, not suitable for stormwater disposal.
As such, we recommend stormwater disposal occur within "clean" poorly-graded gravel
with sand (not containing silt). The following allowable seepage rate should be utilized
for on-site stormwater disposal into "clean" poorly-graded gravel with sand.
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• Poorly-graded gravel with sand (with no silt) ............................. 8 in/hr
Stormwater disposal facilities should be constructed a minimum of 1 foot into the
receiving soil. Seepage beds should be "burrito wrapped" or otherwise maintain a
separation/filter fabric between native fine-grained soils and drain rock/filter sand to
help prevent fine-soil migration into drainable/filtering media. ALLWEST should
observe stormwater disposal facility subgrades to establish if the suitable receiving soil
is encountered (based on civil design), to confirm the allowable/recommended
seepage rate, and to ensure the separation/filter fabric has been properly installed.
The proper separation from bottom of stormwater disposal facilities and seasonal high
groundwater should be maintained. As such, the absence of groundwater, to the
maximum exploration depths observed, should be confirmed throughout seasonal
snow melt and irrigation seasons, to assist civil stormwater design.
We installed slotted PVC pipes within 9 test pits on-site for future groundwater
monitoring. At a minimum, these pipes should be monitored during seasonal snow melt
and irrigation seasons (March to October), or as required by governing jurisdictions, to
confirm the presence (or absence) of groundwater at the site. We remain available to
perform groundwater monitoring, if requested.
7.11 Asphalt Pavements
Prior to pavement section construction, the pavement subgrade should be proof-rolled
as recommended in section 7.2 Site Preparation (or as recommended by local
jurisdictions). Local and collector roadways should be designed for a 20-year
Equivalent Single Axle Load (ESAL) of 33,000 and 370,000, respectively, which is
equivalent to a traffic index (TI) of 6 and 8, respectively. If actual traffic conditions are
different than what is stated, we should be notified so that we may modify our pavement
section design.
Majority of the roadway subgrade consisted of clay or silt-type soils. We performed
California bearing ratio (CBR) testing on a lean clay soil to assist pavement section
design. Based on laboratory testing, we obtained a CBR of 8 for lean clay, which is
equivalent to an R-value of 19.
The following flexible asphalt pavement section design is provided adhering to the
Idaho Transportation Department (ITD), which utilizes the AASHTO pavement design
methodology, and utilizing Ada County Highway District (ACHD) substitution ratios.
Based on subgrade preparation requirements and design assumptions, we
recommend the following pavement sections be utilized for subdivision roadway
construction for local and collector roadways.
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Asphalt Crushed Granular
Pavement Application Concrete Base Course Subbase
(inches) (inches) (inches)
Local Roadway 2.5 4 10
Collector Roadway 3 6 13
Base course and subbase should conform to the material recommendations as noted
in this report and should be placed over a properly prepared subgrade. The subgrade,
subbase, and base course surfaces should slope at no less than 2% away from the
crown of the roadway to help reduce the potential for surface water infiltration into the
underlying pavement subgrade.
Asphalt concrete pavement should be compacted to minimum of 92% of the Rice
density. Crack maintenance on pavements should be performed at a minimum of every
3 years, or when cracking is evident. Crack sealing will help reduce surface water
infiltration into the supporting soils.
8.0 ADDITIONAL RECOMMENDED SERVICES
To maintain continuity and efficiency, we recommend ALLWEST be retained to provide
observations and testing throughout construction. As an independent testing company,
ALLWEST can document the recommendations included in this report are properly
implemented, provide quality control testing, and observe earthwork for conformance
to project specifications. As a minimum, we recommend the following testing and
observations be provided by ALLWEST:
• Observe site stripping, any over-excavations, and compaction of test pit backfill,
and any other soil backfills.
• Observe subgrade proof-rolling and approve subgrades prior to fill construction,
materials placement, or roadway section construction.
• Observe removal of disturbed soil and subgrade stabilization, if required.
• Observe seepage bed subgrades, confirm subsurface seepage rates by
performing seepage testing within stormwater disposal facility locations, and
observe overall construction.
• Conduct compaction testing of fill for general site grading, utilities, and
pavement areas.
• Observe placement of/test asphalt for compaction, oil content and gradation.
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Ada County, Idaho
If we are not retained to provide the recommended construction observation and
testing services, we shall not be responsible for soil engineering-related construction
errors or omissions.
9.0 EVALUATION LIMITATIONS
This report has been prepared to assist planning, design, and construction of the
proposed Black Cat and Chinden Development in Ada County, Idaho. Our services
consist of professional opinions and conclusions made in accordance with generally
accepted geotechnical engineering principles and practices in our local area at the time
this report was prepared. This acknowledgement is in lieu of all warranties either
expressed or implied.
The following plates complete this report:
Appendix A— Site Vicinity Map, Exploration Location Plan
Appendix B — Test Pit Logs, Unified Soil Classification System
Appendix C — Laboratory Test Results
GEOTECHNICAL I ENVIRONMENTAL
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Appendix A
A-1 — Site Vicinity Map
A-2 — Exploration Location Plan
ALLWEST
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Figure A-1 Site Vicinity •
. _• _ I Evaluation
Black • Chinden Development
• •I County, Idaho
Meridian,255 N. Linder Road, Suite 100 Client: Trilogy Development
• • 83642 • • 1
" 1 f1h - "J
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Legend
0 Approximate location of test pit observed by ALLWEST.
Slotted PVC pipe installed in test pit.
Figure A-2 - Exploration Location Plan
Geotechnical Evaluation
ALLWEBT
Black Cat and Chinden Development
Ada County, Idaho
255 N. Linder Road, Suite 100 Client: Trilogy Development
Meridian, Idaho 83642 Project No.: 520-252G
Phone: (208) 895-7898 Fax: (208) 898-3959 Date: November 2020
Appendix B
Test Pit Logs
Unified Soil Classification System (USCS)
ALLWEST
ALLWEST DATE STARTED: 6/18/2020 TP - 1
DATE FINISHED: 6/18/2020 EXCAVATOR: CASE 580C
MERIDIAN,IDAHO OPERATOR:Steve Just
EXCAVATION METHOD:3-ft wide bucket
GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc.
TEST PIT LOG LOGGER:Maxwell Thomas
WEATHER:Sunny
PROJECT:520-252G NOTES:See Figure A-2 in Appendix A for approximate test pit location.
Black Cat and Chinden Development
LATITUDE(DEGREES):N 43°39'46.0332"(43.662787°)
= LONGITUDE(DEGREES):W-116°27'30.0168" (-116.458338°) W
F U U �
o j TOTAL DEPTH: 13'
0CL
DESCRIPTION W U) NOTES
CL Lean CLAY; light brown,stiff, moist Significant roots and vegetation observed to 6
inches.
SILT with sand;tan, medium dense,moist
1
ML
2 Silty SAND;tan,medium dense, moist,weak
cementation/induration observed throughout the soil profile
3
4
SM
5
6—
Poorly-graded GRAVEL with silt and sand;tan, medium dense,
moist °
7 0
GP-GM
0
0
8 Poorly-graded GRAVEL with sand;tan,medium dense, moist
o�
O
O
9 0�
0
O
o�
1 0
O
GP
0
1 O
o�
0
O
0
O
0
1 Test pit terminated at 13 feet.
Slotted PVC pipe installed to 13 feet.
1
WATER LEVELS
a WHILE EXCAVATING
Y AT COMPLETION
1 AFTER EXCAVATING Sheet 1 of 1
ALLWEST DATE STARTED: 6/18/2020 TP - 2
DATE FINISHED: 6/18/2020 EXCAVATOR: CASE 580C
MERIDIAN,IDAHO OPERATOR:Steve Just
EXCAVATION METHOD:3-ft wide bucket
GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc.
TEST PIT LOG LOGGER:Maxwell Thomas
WEATHER:Sunny
PROJECT:520-252G NOTES:See Figure A-2 in Appendix A for approximate test pit location.
Black Cat and Chinden Development
LATITUDE(DEGREES):N 43°39'46.0332"(43.662787°)
= LONGITUDE(DEGREES):W-116°27'24.0048" (-116.456668°) W
F U U �
o j TOTAL DEPTH: 13'
0CL
DESCRIPTION W U) NOTES
Lean CLAY; light brown,stiff, moist Significant roots and vegetation observed to 6
inches.
cL Passing No.200 sieve=89%
BG Moisture content=21%
1 SILT with sand;tan, medium dense,moist LL=33, PL=20,PI= 13
ML
BG Passing No.200 sieve=81%
Moisture content= 10%
2 Poorly-graded GRAVEL with silt and sand;tan, medium dense,
moist °
DG
3 °
GP-GM O
DG
°
4 0
DG
°
O
5 Poorly-graded GRAVEL with sand;tan,medium dense, moist
O Field seepage test performed at 5-1/2 feet.
O Field seepage rate=>30 in/hr.
6-
7
o
Q
o�
8 O
o�
O
9 GP
O
Q
1
0
Q
o�
1 ...wet at 11 feet O
0
Q
1
O
Q
1 Test pit terminated at 13 feet. °
Slotted PVC pipe installed to 13 feet.
1
WATER LEVELS
a WHILE EXCAVATING
Y AT COMPLETION
1 AFTER EXCAVATING Sheet 1 of 1
ALLWEST DATE STARTED: 6/18/2020 TP - 3
DATE FINISHED: 6/18/2020 EXCAVATOR: CASE 580C
MERIDIAN,IDAHO OPERATOR:Steve Just
EXCAVATION METHOD:3-ft wide bucket
GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc.
TEST PIT LOG LOGGER:Maxwell Thomas
WEATHER:Sunny
PROJECT:520-252G NOTES:See Figure A-2 in Appendix A for approximate test pit location.
Black Cat and Chinden Development
LATITUDE(DEGREES):N 43°39'42.6744"(43.661854°)
= LONGITUDE(DEGREES):W-116°27'27.648" (-116.45768°) W
F U U �
o j TOTAL DEPTH: 11'
0CL
DESCRIPTION W U) NOTES
CL Lean CLAY; light brown,stiff, moist Significant roots and vegetation observed to 6
inches.
Sandy SILT;tan,medium dense, moist
1
ML
2 BG Passing No.200 sieve=64%
Moisture content= 16%
Silty SAND;tan,medium dense, moist
3
4
SM
5 ...strong cementation observed from 4 to 6 feet
6 Poorly-graded GRAVEL with silt and sand;tan, medium dense,
moist
GP-GM
7 0
O
Poorly-graded GRAVEL with sand;tan,medium dense, moist J
0
8 0
Q
0�
O
s O
GP p
O
Q
1 0�
0
Q
0
1 Test pit terminated at 11 feet due to caving.
Slotted PVC pipe installed to 11 feet.
1
1
1
WATER LEVELS
a WHILE EXCAVATING
Y AT COMPLETION
1 AFTER EXCAVATING Sheet 1 of 1
ALLWEST DATE STARTED: 6/18/2020 TP - 4
DATE FINISHED: 6/18/2020 EXCAVATOR: CASE 580C
MERIDIAN,IDAHO OPERATOR:Steve Just
EXCAVATION METHOD:3-ft wide bucket
GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc.
TEST PIT LOG LOGGER:Maxwell Thomas
WEATHER:Sunny
PROJECT:520-252G NOTES:See Figure A-2 in Appendix A for approximate test pit location.
Black Cat and Chinden Development
LATITUDE(DEGREES):N 43°39'43.1748"(43.661993°)
= LONGITUDE(DEGREES):W-116°27'21.6684" (-116.456019°) W
F U U �
o j TOTAL DEPTH: 11'
0CL
DESCRIPTION W U) NOTES
Lean CLAY; light brown,stiff, moist Significant roots and vegetation observed to 6
inches.
CL
1
SILT with sand;tan, medium dense,moist
2
3
ML
4
5
6 Silty-CLAY with sand;light brown,stiff, moist
Passing No.200 sieve=71
BG Moisture content=22%
7 LL=23, PL= 18,PI=5
CL-ML
8—
Poorly-graded GRAVEL with silt and sand;tan, medium dense,
moist °
9 0
GP•GM
0
0
1 Poorly-graded GRAVEL with sand;tan,medium dense, moist
GP
O
Q
1 Test pit terminated at 11 feet.
1
1
1
WATER LEVELS
a WHILE EXCAVATING
Y AT COMPLETION
1 AFTER EXCAVATING Sheet 1 of 1
ALLWEST DATE STARTED: 6/18/2020 TP - 5
DATE FINISHED: 6/18/2020 EXCAVATOR: CASE 580C
MERIDIAN,IDAHO OPERATOR:Steve Just
EXCAVATION METHOD:3-ft wide bucket
GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc.
TEST PIT LOG LOGGER:Maxwell Thomas
WEATHER:Sunny
PROJECT:520-252G NOTES:See Figure A-2 in Appendix A for approximate test pit location.
Black Cat and Chinden Development
LATITUDE(DEGREES):N 43°39'42.9948"(43.661943°)
= LONGITUDE(DEGREES):W-116°27'13.5108" (-116.453753°) W
F U U �
o j TOTAL DEPTH: 12.5'
0CL
DESCRIPTION W U) NOTES
Lean CLAY; light brown,stiff, moist Significant roots and vegetation observed to 6
CL inches.
1 SILT;tan,medium dense, moist
ML
2
Silty SAND;tan,medium dense, moist,weak
cementation/induration observed throughout the soil profile
3
4
5
6
SM
7
8
9 BG Passing No.200 sieve=35%
Moisture content= 16%
1 Poorly-graded GRAVEL with silt and sand;tan, medium dense,
m °
GP-GM moist
O
1 Poorly-graded GRAVEL with sand;tan,medium dense, moist
0
GP Q
1
0
Test pit terminated at 12-1/2 feet.
Slotted PVC pipe installed to 12-1/2 feet.
1
1
WATER LEVELS
a WHILE EXCAVATING
Y AT COMPLETION
1 AFTER EXCAVATING Sheet 1 of 1
ALLWEST DATE STARTED: 6/18/2020 TP - 6
DATE FINISHED: 6/18/2020 EXCAVATOR: CASE 580C
MERIDIAN,IDAHO OPERATOR:Steve Just
EXCAVATION METHOD:3-ft wide bucket
GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc.
TEST PIT LOG LOGGER:Maxwell Thomas
WEATHER:Sunny
PROJECT:520-252G NOTES:See Figure A-2 in Appendix A for approximate test pit location.
Black Cat and Chinden Development
LATITUDE(DEGREES):N 43°39'39.636"(43.66101°)
= LONGITUDE(DEGREES):W-116°27'13.5864" (-116.453774°) W
F U U �
o j TOTAL DEPTH: 10'
0CL
DESCRIPTION W U) NOTES
CL Lean CLAY; light brown,stiff, moist Significant roots and vegetation observed to 6
inches.
SILT;tan,medium dense, moist BG Passing No.200 sieve=90%
Moisture content=20%
1
ML
BG Passing No.200 sieve=88%
Moisture content= 12%
2 Silty SAND;tan,medium dense, moist,weak
cementation/induration observed throughout the soil profile
3
SM
4
5 Poorly-graded GRAVEL with silt and sand;tan, medium dense,
moist
GP-GM
O
6 Poorly-graded GRAVEL with sand;tan,medium dense, moist
o�
o Field seepage test performed at 6-1/2 feet.
Q Field seepage rate=>30 in/hr.
7 0�
0
O
o�
GP
O
O
o�
9 O
o�
0
O
10— Test pit terminated at 10 feet due to caving.
Slotted PVC pipe installed to 10 feet.
1
1
1
1
WATER LEVELS
a WHILE EXCAVATING
Y AT COMPLETION
1 AFTER EXCAVATING Sheet 1 of 1
ALLWEST DATE STARTED: 6/18/2020 TP - 7
DATE FINISHED: 6/18/2020 EXCAVATOR: CASE 580C
MERIDIAN,IDAHO OPERATOR:Steve Just
EXCAVATION METHOD:3-ft wide bucket
GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc.
TEST PIT LOG LOGGER:Maxwell Thomas
WEATHER:Sunny
PROJECT:520-252G NOTES:See Figure A-2 in Appendix A for approximate test pit location.
Black Cat and Chinden Development
LATITUDE(DEGREES):N 43°39'41.4648"(43.661518°)
= LONGITUDE(DEGREES):W-116°27'17.2476" (-116.454791°) W
F U U �
o j TOTAL DEPTH:6'
0CL
DESCRIPTION W U) NOTES
CL Lean CLAY; light brown,stiff, moist Significant roots and vegetation observed to 6
inches.
ML SILT;tan,medium dense, moist
1 Silty SAND;tan,medium dense, moist
2 SM
3 Poorly-graded GRAVEL with silt and sand;tan, medium dense,
moist
GP-GM O
4 0
0
Poorly-graded GRAVEL with sand;tan,medium dense, moist
0
5 0
GP Q
o�
0
6 Test pit terminated at 6 feet.
7
8
9
1
1
1
1
1
WATER LEVELS
a WHILE EXCAVATING
Y AT COMPLETION
1 AFTER EXCAVATING Sheet 1 of 1
ALLWEST DATE STARTED: 6/18/2020 TP - 8
DATE FINISHED: 6/18/2020 EXCAVATOR: CASE 580C
MERIDIAN,IDAHO OPERATOR:Steve Just
EXCAVATION METHOD:3-ft wide bucket
GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc.
TEST PIT LOG LOGGER:Maxwell Thomas
WEATHER:Sunny
PROJECT:520-252G NOTES:See Figure A-2 in Appendix A for approximate test pit location.
Black Cat and Chinden Development
LATITUDE(DEGREES):N 43°39'39.402"(43.660945°)
= LONGITUDE(DEGREES):W-116°27'20.124" (-116.45559°) W
F U U �
o j TOTAL DEPTH:7'
0CL
DESCRIPTION W U) NOTES
Lean CLAY; light brown,stiff, moist Significant roots and vegetation observed to 6
CL inches.
1 SILT;tan,medium dense, moist
ML
2
Silty SAND;tan,medium dense, moist
3
SM
4—
Poorly-graded GRAVEL with silt and sand;tan, medium dense,
moist
5 0
GP•GM
0
0
6 Poorly-graded GRAVEL with sand;tan,medium dense, moist
o�
GP
O
Q
7 Test pit terminated at 7 feet.
8
9
1
1
1
1
1
WATER LEVELS
a WHILE EXCAVATING
Y AT COMPLETION
1 AFTER EXCAVATING Sheet 1 of 1
ALLWEST DATE STARTED: 6/18/2020 TP - 9
DATE FINISHED: 6/18/2020 EXCAVATOR: CASE 580C
MERIDIAN,IDAHO OPERATOR:Steve Just
EXCAVATION METHOD:3-ft wide bucket
GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc.
TEST PIT LOG LOGGER:Maxwell Thomas
WEATHER:Sunny
PROJECT:520-252G NOTES:See Figure A-2 in Appendix A for approximate test pit location.
Black Cat and Chinden Development
LATITUDE(DEGREES):N 43°39'39.3876"(43.660941°)
= LONGITUDE(DEGREES):W-116°27'24.858" (-116.456905°) W
F U U �
o j TOTAL DEPTH: 13'
0CL
DESCRIPTION W U) NOTES
Lean CLAY; light brown,stiff, moist Significant roots and vegetation observed to 6
CL inches.
1 SILT;tan,medium dense, moist
2-
MIL
3
Silty SAND;tan,medium dense to dense, moist, moderate
cementation observed throughout the soil profile
4
5
SM
6 ....color change to brown at 6 feet
7 Poorly-graded GRAVEL with silt and sand;tan, medium dense,
moist
O
8—
GP-GM
O
0
9 0
Poorly-graded GRAVEL with sand;tan,medium dense, moist j
0
1 0
O
o�
O
1 O
GP °
O
O
1 0�
0
O
0
1 Test pit terminated at 13 feet.
Slotted PVC pipe installed to 13 feet.
1
WATER LEVELS
a WHILE EXCAVATING
Y AT COMPLETION
1 AFTER EXCAVATING Sheet 1 of 1
ALLWEST DATE STARTED: 6/18/2020 TP - 10
DATE FINISHED: 6/18/2020 EXCAVATOR: CASE 580C
MERIDIAN,IDAHO OPERATOR:Steve Just
EXCAVATION METHOD:3-ft wide bucket
GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc.
TEST PIT LOG LOGGER:Maxwell Thomas
WEATHER:Sunny
PROJECT:520-252G NOTES:See Figure A-2 in Appendix A for approximate test pit location.
Black Cat and Chinden Development
LATITUDE(DEGREES):N 43°39'39.4344"(43.660954°)
= LONGITUDE(DEGREES):W-116°27'30.3408" (-116.458428°) W
F U U �
o j TOTAL DEPTH: 13'
0CL
DESCRIPTION W U) NOTES
SILT;tan,medium dense, moist Tree roots observed to 2 feet.
1
2
ML
3 BG
4
5
Silty SAND;tan,medium dense, moist
6
SM
7—
Poorly-graded GRAVEL with silt and sand;tan, medium dense,
moist
8 0
DG
0 Field seepage test performed at 8-1/2 feet.
o Field seepage rate=>15 in/hr.
9 IQ
0
DG
1 0
GP-GM
IQ
0
1 0
DG
0
1
0
O
1 Test pit terminated at 13 feet.
Slotted PVC pipe installed to 13 feet.
1
WATER LEVELS
a WHILE EXCAVATING
Y AT COMPLETION
1 AFTER EXCAVATING Sheet 1 of 1
ALLWEST DATE STARTED: 6/18/2020 TP - 11
DATE FINISHED: 6/18/2020 EXCAVATOR: CASE 580C
MERIDIAN,IDAHO OPERATOR:Steve Just
EXCAVATION METHOD:3-ft wide bucket
GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc.
TEST PIT LOG LOGGER:Maxwell Thomas
WEATHER:Sunny
PROJECT:520-252G NOTES:See Figure A-2 in Appendix A for approximate test pit location.
Black Cat and Chinden Development
LATITUDE(DEGREES):N 43°39'34.182"(43.659495°)
= LONGITUDE(DEGREES):W-116°27'24.7932" (-116.456887°) W
F U U �
o j TOTAL DEPTH: 11'
0CL
DESCRIPTION W U) NOTES
Lean CLAY; light brown,stiff, moist Significant roots and vegetation observed to 6
CL inches.
BG
1 Sandy SILT;tan,medium dense, moist,weak
cementation/induration observed throughout the soil profile
ML BG Passing No.200 sieve=65%
Moisture content=27%
2
Silty SAND;tan,medium dense, moist,weak cementation
observed throughout the soil profile 3-BG Passing No.200 sieve=67%
Moisture content=27%
4
SM
5
6 Poorly-graded GRAVEL with silt and sand;tan, medium dense,
moist
GP-GM O
7 0
O
Poorly-graded GRAVEL with sand;tan,medium dense, moist J
0
8 o Field seepage test performed at 8 feet.
Q Field seepage rate=>30 in/hr.
0�
s Q
GP
0
O
Q
1 0�
0
Q
0
1 Test pit terminated at 11 feet due to caving.
1
1
1
WATER LEVELS
a WHILE EXCAVATING
Y AT COMPLETION
1 AFTER EXCAVATING Sheet 1 of 1
ALLWEST DATE STARTED: 6/18/2020 TP - 12
DATE FINISHED: 6/18/2020 EXCAVATOR: CASE 580C
MERIDIAN,IDAHO OPERATOR:Steve Just
EXCAVATION METHOD:3-ft wide bucket
GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc.
TEST PIT LOG LOGGER:Maxwell Thomas
WEATHER:Sunny
PROJECT:520-252G NOTES:See Figure A-2 in Appendix A for approximate test pit location.
Black Cat and Chinden Development
LATITUDE(DEGREES):N 43°39'36.7668"(43.660213°)
= LONGITUDE(DEGREES):W-116°27'19.6956" (-116.455471°) W
F U U �
o j TOTAL DEPTH: 12.5'
0CL
DESCRIPTION W U) NOTES
Lean CLAY; light brown,stiff, moist Significant roots and vegetation observed to 6
inches.
1 Passing No.200 sieve=92%
BK Moisture content=20%
CL CBR=8.0
2
3 SILT;tan,medium dense, moist
4
ML
5
6 Silty SAND;tan,medium dense, moist,weak
cementation/induration observed throughout the soil profile
7— SM
8 Poorly-graded GRAVEL with silt and sand;tan, medium dense,
moist
GP-GM
9 0
0
Poorly-graded GRAVEL with sand;tan,medium dense, moist
0
1 0
o�
O
1 GP Q
0�
O
Q
1 0�
0
Test pit terminated at 12-1/2 feet due to caving.
Slotted PVC pipe installed to 12-1/2 feet.
1
1
WATER LEVELS
a WHILE EXCAVATING
Y AT COMPLETION
1 AFTER EXCAVATING Sheet 1 of 1
ALLWEST DATE STARTED: 6/18/2020 TP - 13
DATE FINISHED: 6/18/2020 EXCAVATOR: CASE 580C
MERIDIAN,IDAHO OPERATOR:Steve Just
EXCAVATION METHOD:3-ft wide bucket
GEOTECHNICAL SECTION COMPANY:Just Dig'It Exc.
TEST PIT LOG LOGGER:Maxwell Thomas
WEATHER:Sunny
PROJECT:520-252G NOTES:See Figure A-2 in Appendix A for approximate test pit location.
Black Cat and Chinden Development
LATITUDE(DEGREES):N 43°39'37.1016"(43.660306°)
= LONGITUDE(DEGREES):W-116°27'14.7564" (-116.454099°) W
F U U �
o j TOTAL DEPTH: 10'
0CL
DESCRIPTION W U) NOTES
Lean CLAY; light brown,stiff, moist Significant roots and vegetation observed to 6
CL inches.
1 SILT;tan,medium dense, moist
2
ML
3
4 Silty SAND;tan,dense,moist,strong cementation observed
throughout the soil profile
5— sM
6 Poorly-graded GRAVEL with silt and sand;tan, medium dense,
moist °
GP-GM
O
7 Poorly-graded GRAVEL with sand;tan,medium dense, moist
o Field seepage test performed at 7-1/2 feet.
O Field seepage rate=>30 in/hr.
8—
GP O
Q
o�
9 0
Q
o�
O
10— Test pit terminated at 10 feet due to caving.
Slotted PVC pipe installed to 10 feet.
1
1
1
1
WATER LEVELS
a WHILE EXCAVATING
Y AT COMPLETION
1 AFTER EXCAVATING Sheet 1 of 1
Unified Soil Classification System
MAJOR DIVISIONS SYMBOL TYPICAL NAMES
Well-Graded Gravel,
CLEAN GW Gravel-Sand Mixtures.
GRAVELS GP Poorly-Graded Gravel,
GRAVELS Gravel-Sand Mixtures.
Silty Gravel,
COARSE GRAVELS GM Gravel-Sand-Silt Mixtures.
GRAINED WITH FINES GC Clayey Gravel,
SOILS Gravel-Sand-Clay Mixtures.
Well-Graded Sand,
CLEAN SW Gravelly Sand.
SANDS SP Poorly-Graded Sand,
SANDS Gravelly Sand.
Silty Sand,
SANDS L SM Sand-Silt Mixtures.
WITH FINES Sc Clayey Sand,
Sand-Clay Mixtures.
ML Inorganic Silt,
SILTS AND CLAYS Silty or Clayey Fine Sand.
Inorganic Clay of Low to
LIQUID LIMIT CL Medium Plasticity,
LESS THAN 50% Sandy or Silty Clay.
FINE OL Organic Silt and Clay of Low
GRAINED Plasticity.
SOILS Inorganic Silt, Elastic Silt,
SILTS AND CLAYS MH Micaceous Silt,
Fine Sand or Silt.
LIQUID LIMIT CH Inorganic Clay of High Plasticity,
GREATER THAN 50% Fat Clay.
OH Organic Clay of Medium to High
Plasticity.
Highly Organic Soils PT Peat, Muck and Other Highly
Organic Soils.
ALLWEST
Appendix C
Laboratory Test Results
ALLWEST
Summary of Laboratory Test Results
Moisture Gradation Atterberg Limits
Test Pit Depth Content Liquid Plasticity CBR Sample Classification
No. (Feet) M Gravel Sand Silt/Clay Limit Index (USCS)
M M M M M
2 0.5- 1 21 11 89 33 13 Lean CLAY CL
2 1.5- 2 10 19 81 SILT with sand ML
3 2 -2.5 16 36 64 Sandy SILT ML
4 6.5- 7 22 29 71 23 5 Silty-CLAY with sand CL-ML
5 9 - 9.5 16 65 35 Silty SAND SM
6 0 - 0.5 20 10 90 36 13 Lean CLAY CL
6 1 - 1.5 12 12 88 Lean CLAY CL
11 1.5- 2 27 35 65 Sandy SILT ML
11 3 - 3.5 27 33 67 Silty SAND SM
12 1 -2 20 8 92 36 16 8 Lean CLAY CL
Table C-1
255 N. Linder Road, Suite 100 • Meridian, Idaho 83642 • (208) 895-7895 • Fax (208) 898-3959
www.allwesttesting.com
This report may not be reproduced, except in full, without the permission of ALLWEST.
LIQUID AND PLASTIC LIMITS TEST REPORT
60
Dashed line indicates the approximate
upper limit boundary for natural soils
50 O
�0
' G
40
U
C
X
W
- Z_
N
v 30
c F-
LU C/) '
Q i
J /
a� 20
H
W
/
J
J
Q 10
o A/A
c
L-ML ML or OL MH or OH
0
0 10 20 30 40 50 60 70 80 90 100 110
LIQUID LIMIT
MATERIAL DESCRIPTION LL PL PI %<#40 %<#200 USCS
• Lean Clay 33 20 13 89% CL
c■ Silty Clay with sand 23 18 5 71% CL-ML
CD♦ Lean Clay 36 23 13 90% CL
X
'D♦ Lean Clay 36 20 16 -- 92% CL
m
U
7
O
` Project No. 520-252G Client: Trilogy Development Remarks:
aD Project: Black Cat&Chinden Development
c *Location:TP-2 Depth: 0.5'-l'
■Location:TP-4 Depth: 6.5'-7'
ALocation:TP-6 Depth: 0-0.5'
*Location:TP-12 Depth: F-2'
AL ELW ST
E
H Figure C-1
Tested By: C. Downes Checked By:J.Varozza
California Bearing Ratio
ASTM D 1883
Project: Black Cat & Chinden Development Project No.: 520-252G
Client: Trilogy Development Location: TP-12 @ 1 - 2 ft
Date Tested: 7/2020 Compaction Method: ASTM D1557
Tested By: C. Downes Classification: Lean CLAY (CL)
160
140
120
7A 100
c
0
a 80
0 PSI @ 0.1 inch penetration=80
Ln
60
40
20
0
0 0.1 0.2 0.3 0.4 0.5
Penetration(inches)
CBR @ 0.1 Inch Penetration: 8.0 Maximum Dry Unit Weight (pcf): 113.6
Swell (%): 2.0 Optimum Water Content (%): 13.0
Dry Unit Weight Before Soak(pcf): 103.8 Remold of Max. Dry Unt Wgt(%): 91
Water Content Before Soak (%): 14.4
Water Content After Soak, Top 1 Inch (%): 25.4
Surcharge (psf): 100
Immersion Period (hrs): 96
Reviewed By: James Varozza
Figure: C-2
►LLWET
255 N Linder Rd,Suite 100•Meridian,ID 83642•(208)895-7898•Fax(208)898-3959
www.allwesttesting.com
This report shall not be reproduced except in full without the permission of ALLW EST.
Test Pit: TP-1 TP-2 TP-3 TP-5 TP-6 TP-9 TP-10 TP-12 TP-13
Existing Ground 2538.38 2538.47 2538.47 2542.93 2540.32 2540.85 2542.55 2541.89
Elevation (ft):
Feet Below Ground Surface
Date
8/5/2020 11.5 9.6 >10.8 10.7 9.4 11.0 14.8 11.1 9.5
GW Elevation (ft.) 2526.9 2528.9 <2527.7 2532.2 NA 2529.3 2526.1 2531.5 2532.4
9/2/2020 11.0 9.0 >10.8 10.0 8.7 10.2 14.2 10.2 8.8
GW Elevation (ft.) 2527.4 2529.5 <2527.7 2532.9 NA 2530.1 2526.7 2532.4 2533.1
10/5/2020 11.0 9.0 >10.8 9.8 10.5 14.4 10.2 8.8
GW Elevation (ft.) 2527.4 2529.5 <2527.7 2533.1 NA 2529.8 2526.5 2532.4 2533.1
11/3/2020 >12.9 10.9 >10.8 10.8 11.8 >15.1 11.5 9.7
GW Elevation (ft.) <2525.5 2527.6 <2527.7 2532.1 NA 2528.5 <2525.8 2531.1 2532.2
12/16/2020 >12.9 12.1 >10.8 11.8 13.1 >15.1 12.5 >10.3
GW Elevation (ft.) <2525.5 2526.4 <2527.7 2531.1 NA 2527.2 <2525.8 2530.1 <2531.6
1/18/2021 >12.9 12.6 >10.8 12.5 >13.2 >15.1 >12.7 >10.3
GW Elevation (ft.) <2525.5 2525.9 <2527.7 2530.4 NA <2527.1 <2525.8 <2529.9 <2531.6
3/8/2021 >12.9 >12.9 >10.8 >12.6 * >13.2 >15.1 >12.7 >10.3
GW Elevation (ft.) <2525.5 <2525.6 <2527.7 <2530.3 NA <2527.1 <2525.8 <2529.9 <2531.6
4/8/2021 >12.9 >12.9 >10.8 >12.6 >13.2 >15.1 >12.7 >10.3
GW Elevation (ft.) <2525.5 <2525.6 <2527.7 <2530.3 NA <2527.1 <2525.8 <2529.9 <2531.6
5/13/2021 >12.9 >12.9 >10.8 >12.6 >13.2 >15.1 >12.7 >10.3
GW Elevation (ft.) <2525.5 <2525.6 <2527.7 <2530.3 NA <2527.1 <2525.8 <2529.9 <2531.6
6/14/2021 >12.9 11.6 >10.8 >12.6 * >15.1 >12.7 >10.3
GW Elevation (ft.) <2525.5 2526.9 <2527.7 <2530.3 NA NA <2525.8 <2529.9 <2531.6
7/14/2021 >12.9 11.6 >10.8 >12.6 >15.1 >12.7 >10.3
GW Elevation (ft.) <2525.5 2526.9 <2527.7 <2530.3 NA NA <2525.8 <2529.9 <2531.6
8/9/2021 >12.9 11.6 >10.8 >12.6 >15.1 >12.7 >10.3
GW Elevation (ft.) <2525.5 2526.9 <2527.7 <2530.3 NA NA <2525.8 <2529.9 <2531.6
Pipe destroyed due to farming activity
Table 1
ALLWEST Ground Water Monitoring
Black Cat & Chinden Development
Meridian, Idaho
255 N. Linder Road, Suite 100 Client Name: Trilogy Development
Meridian, Idaho 83642 Project No.: 520-252G
Phone: 208-895-7898 Fax: 208-898-3959 Date: August 2021
" 1 f1h - "J
"Vow.
■ j
■ ■ : 1=A.
■ {
a ;f ■
13
Olt M f
' ■ • ■ ■ O
■ ■
4
■
-12
■ f
o
WP
1
o A
-'— — .. �
40 _—
Legend
0 Approximate location of test pit observed by ALLWEST.
Slotted PVC pipe installed in test pit.
Figure A-2 - Exploration Location Plan
Geotechnical Evaluation
ALLWEBT
Black Cat and Chinden Development
Ada County, Idaho
255 N. Linder Road, Suite 100 Client: Trilogy Development
Meridian, Idaho 83642 Project No.: 520-252G
Phone: (208) 895-7898 Fax: (208) 898-3959 Date: November 2020
Test Pit: TP-1 TP-3 TP-4 TP-5 TP-7 TP-8
Existing Ground 2534.07 2536.34 2536.64 2537.48 2535.73 2534.14
Elevation (ft):
Feet Below Ground Surface
Date
5/17/2021 >11.7 >12.6 >12.6 >11.6 >10.5 >11.5
GW Elevation (ft.) <2522.4 <2523.7 <2524 <2525.9 <2525.2 <2522.6
6/14/2021 >11.7 >12.6 >12.6 >11.6 >10.5 >11.5
GW Elevation (ft.) <2522.4 <2523.7 <2524 <2525.9 <2525.2 <2522.6
7/14/2021 >11.7 >12.6 >12.6 >11.6 >10.5 >11.5
GW Elevation (ft.) <2522.4 <2523.7 <2524 <2525.9 <2525.2 <2522.6
8/9/2021 >11.7 >12.6 >12.6 >11.6 >10.5 >11.5
GW Elevation (ft.) <2522.4 <2523.7 <2524 <2525.9 <2525.2 <2522.6
Table 1
ALLWEST Ground Water Monitoring
Peterman Property Development
Meridian, Idaho
255 N. Linder Road, Suite 100 Client Name: Trilogy Development
Meridian, Idaho 83642 Project No.: 521-113G
Phone: 208-895-7898 Fax: 208-898-3959 Date: August 2021
r -
n _� •l '�
ter, .. — � '4p� �p o ■ � . -
j : f F` .
L -- �
wt
1 - I
Legend
0 Approximate location of test pit observed by ALLWEST.
Slotted PVC pipe installed in test pit.
Figure A-1 - Exploration Location Plan
Geotechnical Evaluation
ALLWEBT
Peterman Property Development
Meridian, Idaho
255 N. Linder Road, Suite 100 Client: Trilogy Development
Meridian, Idaho 83642 Project No.: 521-113G
Phone: (208) 895-7898 Fax: (208) 898-3959 Date: May 2021
Lawrence Lawrence Lawrence
Kennedy Kennedy
Kennedy W City of Star Canal canal Ada County
Canal ANDROMEDA room s Doom 5 coom S RIVERVINE
Lawrence ST 41 E 160236 5420N"E s43di Unincorporated Areas E Lalvr2nce Pioneer 45 E WAY
ZONE Kennedy YURA " 160001 Kennedy Canal 116° 2 314"
116° 30z040G5 AE Canal AVE _ _
-_a. ZONE Yy_N Cit` ...ef. ZONE AE .. a 4 1' 15"
43°41' 15' J Pioneer .
W CARIaEE N
INLET DR �`�� Y•, z IER q
W CELESTIAL DR
Canyon Canal _ Lawra"ca
'nedv
aa37CoomN -eAM —KCanal •� eDi SHIDDEN
Canyon Canal -a' S i�" i' N CREEK LN
STAR iP
RD
W CORIANDER LN Levee `
Boise River
Levee Levee „� 15 ,: 735000 FT
Lev ,, ♦f '�'
t
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u7 � V oC � Q p d N •�� N
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9h
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c;-�. Levee Phyllis Cartel. �N
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as aao W
mN e:. = m I �•{6or
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p WOLD S-HOOL LN <
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' w;„-.. e - - - — .e ms' v. "`" rm - Is
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rl in r• t 1 /-annu I� a n
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41 w
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t1 160001
' THIN TOO WNSHIP _ ^' � - —�---N O TE: MAP AREA SHOO VVN OO N THIS PANEL IS L•CATED WI
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,W LAR�R,Y LN - 27
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as MridiaVn
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I 28"
30 _. 1
Ada County
¢ 9
Unincorporated Areas
z 1600011W is" 725000 FT
` - a`-:
---_:�- -- '
wLEDGERWOOD LN
6 City of Meridian
0 160180
to
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I
- Fivemile Creek -
e ,.� C•A2.KOIAM N N
Yr1"voe�"�34
aszroomN :. THIS AREA SHOWN AT A 720000 FT
\ W BECKYDR-
SCALE OF 1 " = 500'
AdaC°°nt\y ON MAP NUMBER
Unineorp�t�ed Areas <afe'ai
16 '1 16001 CO139
. Sa •rd - r---.
)
Sub t rat ,r 14 T. 4inS
i
ae3t000mN 1f 1
715000 FT
43° 37' 30"
43° 37'30" '
116° 30' 00" 116° 26' 15"
2430000 FT 2435000 FT 2440000 FT
FLOOD HAZARD INFORMATION NOTES TO USERS SCALE
SEE FIS REPORT FOR ZONE DESCRIPTIONSAND INDEX MAP Map Projectlan:
For information and questions about this Flood Insurance Rate Map (FIRM), available products t associated ' �.I NATIONAL FLOOD INSURANCE PROGRAM
with this FIRM, including historic versions, the torten/ map date for each FIRM panel, how to order Universal Transverse Mercator Zone 11N:North Am¢riCan Datum 1983: ""4y
THE INFORMATION DEPICTED ON THIS MAP AND SUPPORTING products, or the National Flood Inwrance Program (NFIP) in general, please call the Western Hemisphere;Vertical Datum:NAVD88 FLOOD INSURANCE RATE MAP
DOCUMENTATION ARE ALSO AVAILABLE IN DIGITAL FORMAT AT FEMA Map Information exchange at 1-877-FEMA-MAP (1-877-336-2627) or visit the FEMA Flood i
Map Service Center website at https:limscfama.gov. Available products may include previously 1 inch = 1,000 feet 1:12,000 'QA ADA COUNTY IDAHO
issued Letters of Map Change, a Flood Insurance Study Report, and/or digital versions of this map. pEeN/aT�F
HTTPS://MSC.FEMA.GOV Many of these products can be ordered or obtained directly from the website. 0 and Incorporated Areas v
0 1,000 2,000 4,000 �T� i ' s
DemmUent FIR Index.g land
adjacent FIRM rdered direelsctly
must obtainthe
copy ice Center
at topanel as wall as feet Fr-i CL PANEL140OF875
Without Base Flood Elevation (BFE) the torten,FIRM Index. These may be ordered tlirectly from the Flood Map Service Center at the number lis,etl y s
'one A,V,A99 above, meters p
With BFE or Depth Zone AE,AO,AH, VE,AR For community and countywftle map dates refer to the Flood Insurance Study Report for this jurisdiction. 0 250 500 1,000 V FEMA
, �. /1 A
SPECIAL FLOOD To detemine if Flootl insurance is available in this community,contact your Insurance agent or call the National i°^ 1 Y L r1
HAZARD AREAS Regulatory Floodway Flood Insurance Program a, 1-8DD-63&6620.
o Base ma information shown on this FIRM was provided in digital format the National Agricultural Imagery PANEL LOCATOR Y _ Panel Contains:
0.2/o Annual Chance Flood Hazard,Areas Program United States Geological Survey(NAIP) dministeretl b,the United States Department of Agriculu m
of 1% annual chance flood with average This information was derived from digital orthophotography at a 2-foot resolution from photography dated 2015. to COMMUNITY NUMBER PANEL SUFFIX
depth less than one foot or with drainage
ADA COUNTY 160001 0140 J
areas of less than one square mile zonex ❑ MERIDIAN,CITYOF 160180 0140 1
Future Condition )%Annual 0130 0135 0134 O sTAR,cInoF 160236 oleo
Chance Flood Hazard Zone O '
Area with Reduced Flood Risk due to Levee Ada County L1
See Notes. zone x
OTHER AREAS OF
FLOOD HAZARD >; ,; ". Area with Flood Risk dueto Levee zone D S=
O
NO SCREEN, Area of Minimal Flood Hazard Zone X 0141 10142 a--+
OTHER co
AREAS '_ Area of Undetermined Flood Hazard zone o Z
1 � 1
GENERAL Channel, Culvert, or Storm Sewer ,3
Y:
STRUCTURES ml ll mlmint Levee, Dike, or Floodwall
E 1e.2 Cross Sections with 1%Annual Chance
17.6 Water Surface Elevation 0139 0143 0144
— - - -- - Coastal Transect
-----' Coastal Transect Baseline
— — Profile Baseline VERSION NUMBER
Hydrographic Feature 2.3.1.1
0250
^^^^^•513^^^^^• Base Flood Elevation Line(BFE) 0231 0232 MAP NUMBER
16001C0140J
OTHER Limit of Study
FEATURES Jurisdiction Boundar MAP REVISED
y PANEL NOT PRINTED DUNE 19, 2020