HomeMy WebLinkAboutCOM2010-00059 Storm Drainage Plan - COM Engineering / Geo-Tech Reports - 6/28/2010 1940631 MASON CO WA
06/03/2009 02.47 PM COV
MIIIIIIIARTIN REYNOLDS $29273 Re. Fee $43.00 Pages. 2
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RETURN ADDRESS GRANTOR(S)(Last,First and Middle Initial)
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A, WA 985Z8 GRANTEE; MASON COUNTY
DEPARTMENT OF PUBLIC WORKS
DECLARATION OF COVENANTS ASSOCIATED WITH
PRIVATELY MAINTAINED STORM DRAINAGE FACILITIES
Declaration of Covenant
In consideration of approval of the development known as
,relating to real property legally described as follc s:
County Assessor's Property Tax Parcel Number AA-in 'SO - [D 1
The undersigned,as owner(s),covenant and agree that:
1. If at any time Mason County reasonably determines that maintenance or repair work is
required to be done to the existing,approved storm drainage facilities installed on the property described
above and located outside of any public right-of-way(which will mean repair and or clean out of the
existing system only to the same standards as originally installed and approved),the Director of the
Department of Public Works shall give the current owners seven days notice that the County intends to
perform such maintenance or repairs,or to have them performed by others.
If the current owners have not completed or are not diligently pursuing the repair or maintenance
of the system and it becomes necessary for Mason Counri to perform the work,the current owners will
assume responsibility for the cost of such maintenance or repair and will reimburse the County within
thirty days of receipt of the invoice.Overdue payments will require payment of interest at the current legal
rate for liquidated judgments,and any costs or fees incurred by the County,should any legal action be
required to collect such payments,will be borne by the parties responsible for said reimbursements.
2. If at any time Mason Counri reasonably determines that the existing and approved storm
drainage system on the property poses a hazard to life and limb,or endangers property,or adversely
affects the safety and operations of a public way, due to failure, damage or non-maintenance of the
existing on-site storm system,and that the situation is so adverse as to preclude written notice to said
owners,the Director of the Department of Public Works may take the measures necessary to eliminate
the hazardous situation (which will mean repair or clean out of the existing system only to the same
standards as originally installed and approved)provided the Director has first made a reasonable effort
to locate said owner before acting.
The current owners will assume responsibility for the cost of such maintenance or repair;and will
reimburse the County within thirty days of receipt of the invoice.Overdue payments will require payment
of interest at the current legal rate for liquidated judgments,and any costs or fees incurred by the County,
should any be bome by the parties responsible for said reimbursements.
3.The owner shall keep the Mason County Public Works Department informed at all times as to
the name, address and telephone number of the contact person responsible for the performance of
maintenance or repair work to the storm drainage facilities.
These covenants are intended to protect the value and desirability of the real property described
above,and to benefit all the citizens of Mason County.They shall run with the land and be binding on
all parties having or acquiring from the current owners or their successors, any right, title or interest
therein,and to the benefit of all the citizens of Mason County.
2y
Signatu� Signature
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Owner Owner
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Address Address
&//., wY9 98528
City,State,Zip City,State,Zip
Phone:,760- NO- 6029 Phone:
STATE OF WASHINGTON,
ss. (INDIVIDUAL ACKNOWLEDGEMENT)
County of MASON
1, ���,Notary Public in and for the State of Washington,residing at ►✓ �
GSo
Caw ,do hereby certify that on this c3 day of SuAJ,& ,personally appeared before
meey,-?p/C,5 to me known to be the individual_described
in and who executed the within instrument and acknowledged that he, signed and sealed the same
as &-5 free and voluntary act and deed for the uses and purposes herein mentioned.
GIVEN UPI HAND AND OFFICIAL SEAL this�ta co day ofT,111 PSZ_.
9 ,
_ $or�ur =�
Notary Public irk and for the State of Washington,residing at
�d f o ! •yu c�n?jr in said County.
t �
r WI'sNp�� My Commission expires
4nnnnua�
ESE KEPT IN THE
PARCEL FlMFmon County Review Checklist
or a Stormwater Plan
Instructions:
This checklist is intended to assist Staff in the review of a Stormwater Plan. The Stormwater Plan is
reviewed for completeness with respect to the 2005 Department of Ecology Stormwater Manual. If an
item is found to be not applicable, the Plan should explain the basis for the conclusion. The Plan is also
reviewed for clarity and consistency. If the drawings, discussion, or recommendations are not
understandable, they should be clarified. If they do not appear internally consistent or consistent with the
application or observations on site, this needs to be corrected or explained. If resolution is not achieved
with the author, staff should refer the case to the Planning Manager or Director.
Applicant's Name: X&&� — V 00 t
Permit# um '"V to ` nyV 15 I Parcel#
Date(s) of the Document(s) reviewed: Tto
SECTION I—Construction SWPPP Narrative
(1) Construction Stormwater Pollution Prevention Elements:
(a) Describe how each of the Construction Stormwater Pollution Prevention Element has been
addressed through the Construction SWPPP.
OK? Comment:
(b) Identify the type and location of BMP's used to satisfy the required element.
OK? Comment:
(c) Written justification identifying the reason an element is not applicable to the proposal.
OK? Comment:
(d) 12 Required Elements —Construction Stormwater Pollution Prevention Plan
(1) Mark Clearing Limits.
OK? Comment:
(2) Establish Construction Access.
OK? Comment: p
(3) Control Flow Rates. n�A C�/`
OK? Comment:
(4) Install Sediment Controls.
OK? Comment:
(5) Stabilize Soils.
OK? Comment:
(6) Protect Slopes.
OK? Comment:
(7) Protect Drain Inlets.
OK? Comment:
(8) Stabilize Channels and Outlets.
OK? Comment:
(9) Control Pollutants.
OK? Comment:
(10)Control De-Watering.
OK? Comment:
(11)Maintain BMP's.
OK? Comment:
(12)Manage the Project.
OK? Comment:
Page 1 Form Effective May 2009
(2) Project Description.
(a) Total project area (acres/square feet). GI
OK? Comment: (J7�
(b) Total Proposed impervious area (acres/square feet).
OK? Comment:
(c)Total proposed area to be disturbed, included off-site borrow and fill areas (acres/square feet).
OK? Comment:
(d) Total volumes of proposed cut and fill (cubic yards).
OK? Comment:
(3) Existing Site Conditions.
(a) Description of the existing topography.
OK? Comment:
(b) Description of the existing vegetation.
OK? Comment:
(c) Description of the existing drainage.
OK? Comment:
(4)Adjacent Areas.
(1) Description of adjacent areas which may be affected by the site disturbance
(a) Streams n
OK? Comment: ,v
(b) Lakes
OK? Comment:
(c)Wetlands
OK? Comment:
(d) Residential Areas
OK? Comment:
(e) Roads
OK? Comment:
(f) Other
OK? Comment:
(II) Description of the downstream drainage path leading from the site to the receiving body of water
(minimum distance of 400 yards).
OK? Comment: U�
(5) Critical Areas:
(a) Description of critical areas that are on or adjacent to the site.
OK? Comment:
(b) Description of special requirements for working in or near critical areas.
OK? Comment:
(6) Soils: Description of on-site soils.
(a) Soil name
OK? Comment:
(b) Soil mapping unit
OK? Comment:
(c) Erodibility
OK? Comment:
(d) Settleability
OK? Comment:
(e) Permeability
OK? Comment:
(f) Depth
OK? Comment:
(g) Texture
OK? Comment:
Page 2 Form Effective May 2009
(h) Soil Structure
OK? Comment:
(7) Erosion Problem Areas.
(a) Description of potential erosion problems on site
OK? Comment: site
(8) Construction Phasing.
(a) Construction sequence.
OK? Comment:(b) Construction phasing (if proposed).
OK? Comment:
(9) Construction Schedule.
I. Provide a proposed construction schedule
OK? Comment:
II. Wet Season Construction Activities Ci��(1�► /�
(a) Proposed wet season construction activities.
OK? Comment:
(b) Proposed wet season construction restraints for environmentally sensitive/critical areas.
OK? Comment:
(10)Engineering Calculations. Provide design calculations.
(a) Sediment Ponds/Traps.
OK? Comment:
(b) Diversions.
OK? Comment: �'�,
(a) Waterways. �/!� 'cat 3
OK? Comment:
(b) Runoff/Stormwater Detention Calculations.
OK? Comment:
(11)Operations and Maintenance
(a). An operation and maintenance schedule shall be provided for all proposed stormwater facilities
and BMPs, and the party(or parties) responsible for maintenance and operation shall be
identified. An operation and maintenance (O & M) Declaration of Covenant will be required to
cover all privately owned and maintained stormwater facilities. O & M Declaration of Covenant
forms are available at the Mason County Permit Assistance Center, 426 W. Cedar Street,
Shelton, WA 98584. The proponent shall record a copy of the completed Declaration with the
Mason County Auditors' office. A copy of the recorded document must be submitted to the Permit
Assistance Center together with this completed Checklist.
OK? Comment:
f,y,zAl
SECTION II—Erosion and Sediment Control Plans
(1) General. '
(a) Vicinity Map.
OK? Comment:
(b) Clearing and Grading Approval Block.
OK? Comment:
(c) Erosion and Sediment Control Notes.
OK? Comment:
(2) Site Plan.
(a) Legal description of subject property.
OK? Comment:
(b) North Arrow.
OK? Comment:
Page 3 Form Effective May 2009
a
i
(c) Indicate boundaries of existing vegetation, e.g. tree lines, pasture areas, etc.
OK? Comment:
(d) Identify and label areas of potential erosion problems. CAA,
OK? Comment:
�rr
(e) Identify any on-site or adjacent surface waters, critical areas and associated buffers.
OK? Comment:
(f) Identify FEMA base flood boundaries and Shoreline Management boundaries (if applicable).
OK? Comment:
(g) Show existing and proposed contours.
OK? Comment:
(h) Indicate drainage basins and direction of flow for individual drainage areas.
OK? Comment:
(i) Label final grade contours and identify developed condition drainage basins.
OK? Comment:
Q) Delineate areas that are to be cleared and graded.
OK? Comment:
(k) Show all cut and fill slopes indicating top and bottom of slope catch lines.
OK? Comment:
(3) Conveyance Systems. Ci
(a) Designate locations for swales, interceptor trenches, or ditches.
OK? Comment:
(b) Show all temporary and permanent drainage pipes, ditches, or cut-off trenches.
OK? Comment:
(c) Provide minimum slope and cover for all temporary pipes or call out pipe inverts.
OK? Comment:
(d) Show grades, dimensions, and direction of flow in all ditches, swales, culverts, and pipes.
OK? Comment:
(e) Provide details for bypassing off-site runoff around disturbed areas.
OK? Comment:
(f) Indicate locations and outlets of any dewatering systems.
OK? Comment:
(4) Location of Detention BMP's.
(a) Identify location of detention BMP's.
OK? Comment:
(5) Erosion and Sediment Control Facilities.
(a) Show the locations of sediment trap(s), pond(s), and pipe structures. G o
OK? Comment:
(b) Dimension pond berm widths and inside and outside pond slopes.
OK? Comment:
(c) Indicate the trap/pond storage required and the depth, length, and width dimensions.
OK? Comment:
(d) Provide typical section views through pond and outlet structure.
OK? Comment:
(e) Provide typical details of gravel cone and standpipe, and/or other filtering devices.
OK? Comment:
(f) Detail stabilization techniques for outlet/inlet.
OK? Comment:
(g) Detail control/restrictor device location and details.
OK? Comment:
(h) Specify mulch and/or recommended cover of berms and slopes.
OK? Comment:
(i) Provide rock specifications and detail for rock check dams.
OK? Comment:
(j) Specify spacing for rock check dams as required.
OK? Comment:
Page 4 Form Effective May 2009
i
(k) Provide front and side sections of typical rock check dams.
' OK? Comment:
(1) Indicate the locations and provide details and specifications for silt fabric.
OK? Comment:
(m) Locate the construction entrance and provide detail.
OK? Comment:
(6) Detailed Drawings. C`(
(a) Any structural practices used that are not referenced in the Ecolo'gy Manual shout explained
and illustrated with detailed drawings.
OK? Comment:
(7) Other Pollutant BMP's. �—
(a) Indicated on the site plan the location of BMP's to be used for the control of p Ilutants other than
sediment, e.g. concrete wash water.
OK? Comment:
(8) Monitoring Locations.
(a) Indicate on the site plan the water quality sampling locations to be used for monitofring rwaNter .,
quality on the construction site, if applicable.
OK? Comment: , /
V
Are the Documents signed and/stamped?
Type and#of Licensel�t..
If not approved, what is the next action/recommendation for further action? r
�r
Reviewed by on
Time spent in review:
SECOND REVIEW/ UPDATE:
Reviewed by on
Time spent in second review:
THIRD REVIEW/ UPDATE:
Reviewed by on
Time spent in third review:
Disclaimer: Mason County does not certify the quality of the work done in this Stormwater Plan.
Page 5 Form Effective May 2009
Mason County
Construction Stormwater Pollution Prevention Plan Checklist
✓ h. Specify mulch and/or recommended cover of berms and slopes.
i. Provide rock specifications and detail for rock check dams.
✓ j. Specify spacing for rock check dams as required.
✓ k. Provide front and side sections of typical rock check dams.
✓ 1. Indicate the locations and provide details and specifications for silt fabric.
✓ m. Locate the construction entrance and provide a detail.
b. Detailed Drawings
C-2: (WSDOT Std. Plan References)
✓ a. Any structural practices used that are not referenced in the Ecology Manual should
be explained and illustrated with detailed drawings.
7. Other Pollutant BMPs
✓ a. Indicate on the site plan the location of BMPs to be used for the control of
pollutants other than sediment, e.g. concrete wash water. C-1: ESC#13
8. Monitoring Locations
NA a. Indicate on the site plan the water quality sampling locations to be used for
monitoring water quality on the construction site, if applicable.
I certify that the stormwater plan submitted for this project fulfills the applicable
provisions of the 2005 DOE Stormwater Manual.
r
Q
05/21/2010 05-21-10
Engineer Date
ONeI.
NOTE DRAWNG COPY IS NSCRBED MATH DIGITIZED
Applicant Date SIGNATURE&DATE. ORIGINAL SIGNED DRAWING IS
ARCHNED NI THE SIGNATURE ENGINEERS OMCF-
Place signed stamp here
RECEIVED
JUN 2 8 2010
Stormwater Checklist DOE 2005 Manual.doc 426 W. CEDAR ST. 5
Updated May 20, 2009
Mason County
Construction Stormwater Pollution Prevention Plan Checklist
Section II - Erosion and Sediment Control Plans
1. General
a. Vicinity Map, See page/paragraph C-1 (text) "PROJECT INFORMATION"
✓ b. Clearing and Grading Approval Block, See page/paragraph C-1
✓ c. Erosion and Sediment Control Notes, See page/paragraph C-1
2. Site Plan
C-1
✓ a. Legal description of subject property
✓ b. North Arrow
✓ c. Indicate boundaries of existing vegetations, e.g. tree lines, pasture areas, etc.
✓ d. Identify and label areas of potential erosion problems, See
page/paragraph C-1: (Clearing Area)
N/A e. Identify any on-site or adjacent surface waters, critical areas and associated buffers
NIA f. Identify FEMA base flood boundaries and Shoreline Management boundaries (if
applicable), See page/paragraph
✓ g. Show existing and proposed contours
✓ h. Indicate drainage basins and direction of flow for individual drainage areas
i. Label final grade contours and identify developed condition drainage basins
✓ j. Delineate areas that are to be cleared and graded
v k. Show all cut and fill slopes indicating top and bottom of slope catch lines
3. Conveyance Systems
C-1 & C-2
a. Designate locations for swales, interceptor trenches, or ditches
✓ b. Show all temporary and permanent drainage pipes, ditches, or cut-off trenches
Required for erosion and sediment control
✓ c. Provide minimum slope and cover for all temporary pipes or call out pipe inverts
d. Show grades, dimensions, and direction of flow in all ditches, swales, culverts, and
pipes
N/A e. Provide details for bypassing off-site runoff around disturbed areas
N/A f. Indicate locations and outlets of any dewatering systems
4. Location of Detention BMPs
C-2
V a. Identify location of detention BMPs. (Infiltration Trench)
5. Erosion and Sediment Control Facilities
C-1
N/A a. Show the locations of sediment trap(s), pond(s), and pipe structures.
N/A b. Dimension pond berm widths and inside and outside pond slopes.
N/A c. Indicate the trap/pond storage required and the depth, length, and width dimensions.
N/A d. Provide typical section views through pond and outlet structure.
N/A e. Provide typical details of gravel cone and standpipe, and/or other filtering devices.
N/A f. Detail stabilization techniques for outlet/inlet.
N/A g. Detail control/ restrictor device location and details.
Stormwater Checklist DOE 2005 Manual.doc 4
Updated May 20, 2009
Mason County
Construction Stormwater Pollution Prevention Plan Checklist
✓ c. Erodibility, See page/paragraph SR: SECT. 10.
✓ d. Settleability, See page/paragraph SR: SECT. 10.
✓ e. Permeability, See page/paragraph SR: SECT. 10.
✓ f. Depth, See page/paragraph SR: SECT. 10.
✓ g. Texture, See page/paragraph SR: SECT. 10.
✓ h. Soil Structure, See page/paragraph SR: SECT. 10.
7. Erosion Problem Areas
✓ Description of potential erosion problems on site. See page/paragraph SR: SECT. 10.
8. Construction Phasing
✓ a. Construction sequence, See page/paragraph C-1: "EROSION CONTROL CONST. SEQUENCE"
✓ b. Construction phasing (if proposed) , See page/paragraph C-1: "CONSTRUCTION PHASING"
9. Construction Schedule
✓ I. Provide a proposed construction schedule, See page/paragraph C-1: "CONSTRUCTION SCHEDULE"
✓ II. Wet Season Construction Activities
✓ a. Proposed wet season construction activities, See page/paragraph C 1: ESC#3
N/A b. Proposed wet season construction restraints for environmentally
sensitive/critical areas. See page/paragraph
10. Engineering Calculations
✓ 1. Provide Design Calculations.
a. Sediment Ponds/Traps, See page/paragraph DR: SECT. 13.
N/A b. Diversions, See page/paragraph DR: SECT. 13.
N/A c. Waterways, See page/paragraph DR: SECT. 13. DR: SECT. 10.
✓ d. Runoff/Stormwater Detention Calculations, See page/paragraph
11. Operations and Maintenance.
✓ a. An operation and maintenance schedule shall be provided for all proposed stormwater
facilities and BMPs, and the party (or parties) responsible for maintenance and
operation shall be identified. An operation and maintenance (OitM) Declaration of
Covenant will be required to cover all privately owned and maintained stormwater
facilities. O&M Declaration of Covenant forms are available at the Mason County
Permit Assistance Center, 426 W. Cedar Street, Shelton, WA 98584. The proponent
shall record a copy of the completed Declaration with the Mason County Auditors'
office. Acopy of the recorded document must be submitted to the Permit Assistance
Center together with this completed Checklist.
See page/paragraph C-1: ESC#15
Stormwater Checklist DOE 2005 Manual.doc 3
Updated May 20, 2009
Mason County
Construction Stormwater Pollution Prevention Plan Checklist
✓ 6. Protect Slopes, See page/paragraph C-1: ESC#5
✓ 7. Protect Drain Inlets, See page/paragraph C-1: ESC#s
✓ 8. Stabilize Channels and Outlets, See page/paragraph C-1: ESC#7
✓ 9. Control Pollutants, See page/paragraph C-1: ESC#13
✓ 10. Control De- Watering, See page/paragraph C-1: ESC#9 & #12
✓ l 1. Maintain BMPs, See page/paragraph C-1: ESC#14
✓ 12. Manage the Project, See page/paragraph C-1: ESC#3, #11. & #15
2. Project Description
✓ a. Total project area. Acres 0.46 C-1: GRADING PLAN
✓ b. Total proposed impervious area. Acres 0.20 Gar DR: SECT. 2.b.
✓ c. Total proposed are to be disturbed, included off-site borrow and fill areas. Ac.0.46 60
&�gI C-1: GRADING PLAN
✓ d. Total volumes of proposed cut and fill. Cubic Yards C-1: GRADING PLAN
(300cy+300cy= 600cy)
3. Existing Site Conditions
✓ a. Description of the existing topography. See page/paragraph DR: SECT. 3.a.
✓ b. Description of the existing vegetation. See page/paragraph DR: SECT. 3.b.
✓ c. Description of the existing drainage. See page/paragraph DR: SECT. 3A, 3.1., 5., 6., & 7.
4. Adjacent Areas
✓ I. Description of adjacent areas that may be affected by the site disturbance
✓ a. Streams, See page/paragraph DR: SECT. 3.e. (None)
✓ b. Lakes, See page/paragraph DR: SECT. 3.e. (None)
✓ c. Wetlands, See page/paragraph DR: SECT. 3.e. (None)
✓ d. Residential Areas, See page/paragraph DR: SECT. 3.1.
✓ e. Roads, See page/paragraph DR: SECT. 3.1.
NSA f. Other, See page/paragraph
✓ II. Description of the downstream drainage path leading from the site to the receiving
body of water. (Minimum distance of 400 yards), See page/paragraph DR: SECT. 7. &
WATERSHED EXHIBIT
5. Critical Areas
✓a. Description of critical areas that are on or adjacent to the site. See
page/paragraph DR: SECT 3.e. (None)
✓ b. Description of special requirements for working in or near critical areas.
See page/paragraph DR: SECT 3.e. (None)
6. Soils
✓ Description of on-site soils.
✓ a. Soil name(s) , See page/paragraph SR: SECT. 4.
✓ b. Soil mapping unit, See page/paragraph SR: SOIL SURVEY MAP
Stormwater Checklist DOE 2005 Manual.doc 2
Updated May 20, 2009
Mason County
Construction Stormwater Pollution Prevention Plan Checklist
Project Name: ISLEY ALLYN PARCEL
County Project No. PARCELS 122205068001 &68002
Review Date: 05-21-10
Construction SWPPP Reviewer: MICHAEL F.WNBK P.E.
Minimum Reauirements of the DOE 2005 Stormwater Manual
The Stormwater checklist identifies the minimum requirements of the DOE 2005 Stormwater
Manual. The Checklist is intended to identify the locations within the plan that addresses the
minimum requirements. Mason County will not perform a technical evaluation of the
submittal. Rather, the checklist provides a guide to allow Mason County to review the
submittal and determine if the applicant has addressed the minimum features that make up a
Stormwater plan.
It is incumbent upon the applicant and his/her engineer to fulfill all the applicable
requirements of the 2005 Stormwater Plan as it relates to the proposed project. Review by
Mason County is intended to determine if the plan has addressed the minimum requirements.
Applicant's engineer shall be responsible for the technical accuracy of the submitted
Stormwater plan.
During construction of the project, the stormwater plan engineer of record or his/her
authorized representative shall inspect the site to ensure the stormwater plan is being
implemented as designed. Upon completion of the project, the engineer or his authorized
representative shall be required to certify that the stormwater plan has been implemented as
designed.
Failure to meet the minimum requirements could result in delay or rejection of the
application until the deficiencies are corrected. LEGEND:
Section I - Construction SWPPP Narrative C-1, C-2= CONST. PLANS
DR = DRAINIAGE REPORT
1. Construction Stormwater Pollution Prevention Elements
SR =SOILS REPORT
DR: SECTION 13
✓ a. Describe how each of the Construction Stormwater Pollution Prevention Element has
been addressed though the Construction SWPPP.
V' b. Identify the type and location of BMPs used to satisfy the required element.
c. Written justification identifying the reason an element is not applicable to the
proposal.
12 Required Elements-Construction Stormwater Pollution Prevention Plan
✓ 1. Mark Clearing Limits, See page/paragraph C-1: ESC#2
✓ 2. Establish Construction Access, See page/paragraph C-1: ESC#10
✓ 3. Control Flow Rates, See page/paragraph C-1: ESC#6
✓ 4. Install Sediment Controls, See page/paragraph C-1: ESC#4
✓ 5. Stabilize Soils, See page/paragraph C-1: ESC#1
Stormwater Checklist DOE 2005 Manual.doc 1
Updated May 20, 2009
Michael F. Wnek, P.E.
Consulting Civil Engineer
3388 NW Byron St, Suite 200, Silverdale, WA 98383, 360-692-3802 (voice)360-692-1051 (fax)
Soils Report for Storm Drainage
ISLEY ALLYN PARr.Fl -
located in:
Mason COUNTY
prepared for:
Bill Isley
417 Madrona Way NE
Bainbridge Island, WA 98110-1823
206-713-25689
May 17, 2010
CONTENTS
Soils Narrative Pages 2-3
Soil Test Locations Page 4
Test Pit Data Page 5
Textural Triangle USDA Page 6
Mason Co. Soil Survey Data Page 7-9
Project Number: 499
T
By the seal and signature here affixed, Q�
certify that the enclosed report was
accomplished by myself, and that I am 05-17-10
currently a registered engineer of good ��
standing in the State of Washington.
ANAL
NOTE: OR W G COPY S WREM 1N7N aaTM
SIGNATURE&WE ORIGMAL SQM MOM IS
AKHVEO M TK SK#AMM MPUWS OFFICE.
1
ISLEY ALLYN PARCEL MICHAEL F. WNEK, P.E., PS
Soils Report for Drainage May 17, 2010
SOILS NARRATIVE
1. PROJECT DESCRIPTION:
■ Development of 2 commercial/ residential buildings
■ Associated parking &driveways, walkways & lawn/landscaping
2. REPORT OBJECTIVES:
• Soils analysis for storm infiltration values.
■ Suitability of site for infiltration facilities.
3. PROJECT LOCATION:
Legal Description Section 20, T22N, R1W, W.M.
Parcel Address Lakeland drive
Parcel Numbers 122205068001, 122205068002
Parcel Size 2.74 acre
Project Size 0.50 acre
4. SOILS SURVEY DESIGNATION (Soil Conservation Service Manual):
■ SINCLAIR (#59) gravelly sandy loam
5. HYDROLOGIC CLASSIFICATION:
■ GROUP "C"
6. TOPOGRAPHY: The project topography is very flat, with a maximum slope of about 15%.
7. CRITICAL AREAS: None of record.
8. PROJECT NARRATIVE: Most of the excavation required for the project will be for building
foundations, typically 4-6 feet at the deepest locations. The anticipated storm mitigation
measures will include porous pavement combined with a roof infiltration trench.
9. TEST PITS & SAMPLES: One soil test hole was accomplished by hand tools to a depth of
4.5-feet. One soil sample was taken for classification. An in-situ infiltration test was performed
in the test hole to verify visual observations of the soil type. Lab tests were performed for
textural classification and settleability.
10. SOILS NARRATIVE: The soil structure is typical of the Mason County locale: glacially
deposited materials. The test hole appeared to contain native soils, no fill materials were
encountered. The soils also appear to replicated the Soils Survey classifications.
No seepage or evidence of a perched water table was found. The materials became denser
with depth, particularly below the 3.5-foot level; although the material was not impenetrable, the
2
ISLEY ALLYN PARCEL MICHAEL F. WNEK, P.E., PS
Soils Report for Drainage May 17, 2010
depth obtained was limited by the practical reach of hand tools combined with the density &
occurrence of rocks to 8" diameter.
Textural analysis shows a high percentage of silt (almost 50%), however also showed lack of a
clay fraction. The settleability test showed that turbidity was negligible after 24 hours.
The erosion potential for the soil classification is listed as moderate, with the high silt
percentage offset by the amount of gravel.
11. RECOMMENDATIONS: The site soils are not ideal for storm runoff infiltration, due to the
relatively low percentage of sand. However, infiltration is currently the preferred mitigation
practice. Since the size of the project is relatively small, infiltration can be achieved as long as
an adequate footprint area can be provided.
Infiltration values are derived using procedures outlined in Section 3.3.6 of the Stormwater
Management Manual for Western Washington, Washington State Dept. of Ecology, February
2005. The prescribed infiltration rate is based on textural classification. A correction factor of
"2" (50% reduction) is applied; the runoff directly connected to the infiltration facilities will be
relatively 'clean' roof runoff therefore a larger factor is not warranted. The in-situ measured rate
also is sufficient to not warranted use of a larger correction factor.
INFILTRATION RATES "
APPLICATION USDA USC INFILTRATION RATE
CLASSIFICATION CLASSIFICATION
Infiltration Trench Sandv Loam SM 0.50 in/ hr
* safety factor already factored in
During site work there will be potential for erosion & sedimentation. However, due to the limited
size of the work area, only basic Best Management Practices are warranted; and should
concentrate on avoidance of concentrated flows that could create soil movement, turbidity, &
off-site discharges.
12. REPORT LIMITATIONS: This report is provided to recommend design values for storm
drainage design. It is not intended to be a geotechnical evaluation of the project soils for
building construction.
3
ISLEY ALLYN PARCEL Michael F. Wnek, P.E., PS
Soils Report for Storm Drainage May 17, 2010
SOILS TEST HOLE LOCATIONS NORTH
SCALE" 1"=60'
1ir
At
r, r, r
Ilk I
rr
i
OWLS
i
4
SOIL TEST PIT
Date: 05-n-lo
Project: =SLE ALLI 1 PARx r -
Method: VW'Avlx� `r0o LS
Number: H N L
cation: 20' Ir-u PRS�-TECT r-R-oK ESA 0 P", 0-ew
A L-Okic. I-AK-ELAO D
Depth Class Color S e size Wsture Density Roots Seepage MotHing
Notes:
i
DI=.
0,1S- I.zS Lzw ewJ►J s��T g-'' upkt MEL Y �j ^�
Notes:
Nay L-T.
I•ZS-Z,7� L..oAM ,BP�,�+J 51�-T Z" A*&{.P MBA Y
Notes:
2• L RU SY L..A4 Lk-
2 4& 4.51, n
LOAM
g'� DM�►Q J ti1 r l r l
Notes:
vE9-1 DENSE ROCKS AUSTLI
DENS EST )l1 vs f-Al► 8E,G%al AT a.5- rogr Leq E
Notes:
General Observations:
Stopped test @',S'due to seepago. 1 I f
Sample taken @ p,2'/ hr�
14, o� ti , z5 24„
IZ , L.S LI , ZI
IZ= 3� I . IS'
5
STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN
Figure III--3.1 U.S.D.A. Textural Triangle
ISLEY ALLYN PARCEL
05-17-10
Textural Triangle U.S.D.A.
100% clay
90 to
so 20
TO Clay 30
60 \/V40 ,e
4 A CIO
SO Silt Sp +
clay
dp Sand 60
cfay / . Clay ilty
clay
30 Sandy clay oam loam xp
loam /
21) LoaM r so
10 3: s srsg ' Slit l}0
Xaleel # �' i01T silt
S�N4d
100% sand 90 so TO 60 so 40 30 20 10 100% silt
Porcent sand
Test Hole
#HH1
@ -4.25-ft
Sand = 53%
Silt = 47%
Clay= 0%
—- ---" FEBRUARY, 199
6
ISLEY ALLYN PARCEL Michael F. Wnek, P.E., PS
Soils Report for Storm Drainage May 17, 2010
SOILS SURVEY MAP
^4
y �
lf' rn
Washington Y ¢
129
9^,
r
y _tl
Ab = Alderwood
So = Sinclair
Table H. - Engineering Index Properties - Continued
Kitsap County Area,Washington
Classification Fragments Percent Passing Sieve Number
Map Symbol Depth USDA Texture Liquid Plasticity
and Soil Name p >10 3-10 Limit Index
Unified AASHTO Inches Inches 4 10 40 200
In Pct Pct Pet
57:
SHELTON 0-11 Extremely Gravelly Sandy GP-GM A-1 0 0-5 25.40 15-25 10-15 5-10 15-25 NP-5
Loam
11-22 Extremely Gravelly Sandy GM A-1 0 0-10 2545 2040 20-35 10-25 15-25 NP-5
Loam
Very Gravelly Loam
Very Gravelly Sandy Loam
22-60 Cemented - 0 0 — -- --- --- --- —
58:
SHELTON 0-3 Extremely Gravelly Sandy GP-GM A-1 0 0-5 25AO 15-25 10-15 5-10 15-25 NP-5
Loam
00 3-22 Extremely Gravelly Sandy GM A-1 0 0-10 25-45 20-40 20-35 10-25 15-25 NP-5
Loam
Very Gravelly Loam
Very Gravelly Sandy Loam
22-60 Cemented --- — 0 0 -- --- --- --- -- -
MCKENNA 0-6 Gravelly Loam GM A-4 0 0-5 60-80 55-75 55-65 40-60 20-40 NP-10
ML
6-28 Very Gravelly Clay Loam GC A-2 0 0-5 30-60 25-50 20-50 20-45 25-45 5-20
Very Gravelly Silt Loam GC-GM A-4
Very Gravelly Loam A-6
A-7
28-60 Cemented --- — 0 0 -- -- --- --- --- -
59:
SINCLAIR 0-8 Very Gravelly Sandy Loam GM A-1 0 0-5 40-60 35-50 25-35 10-20 15-25 NP-5
8-25 Very Gravelly Loam GM A-1 0 0-5 45-55 35-50 25-30 10-20 15-25 NP-5
Very Gravelly Sandy Loam
25-60 Cemented — — 0 0 -- -- --- -- -- -
60:
USDA Natural Resources
Conservation Service Distribution Generation Date: 11/15/02 Page 17 of 18
Physical Soil Properties
Kitsap County Area,Washington
Erosion factors Wind Wind
Saturated Available Linear
Map symbol Moist bulk Organic erodi- erodi-
and soil name Depth Sand Silt Clay density hydraulic water extensi matter bility bility
conductivity capacity bility Kw Kf T group index
In Pct Pct Pct 9/cc micro m/sec In/!n Pct Pct
59:
Sinclair 0-8 -- — 5-15 0.85-1.10 14.00-42.00 0,06-0.08 0.0-2.9 3.0-7.0 .10 .28 3 4 86
8-25 — — 5-15 0.85-1.10 14.00-42.00 0.07-0.11 0.0-2.9 0.5-3.0 .10 .32
25-60 — — 5-10 1.70-2.00 0.01-0.42 0.00 0.0-2.9 0.0-0.5 .10 .32
CID
USDA Natural Resources This report shows only the major soils In each map unit.Others may exist.
Tabular Data Version:5
Conservation Service Tabular Data Version Date:09/22/2009 Page 1 of 3
Michael F. Wnek, P.E., PS
Consulting Civil Engineer
3388 NW Byron St, Suite 200, Silverdale, WA 98383, 360-692-3802
Drainage Report
ISLEY ALLYN PARCEL
located in:
Mason COUNTY
prepared for:
Bill Isley
417 Madrona Way NE
Bainbridge Island, WA 98110-1823
206-713-25689
May 21 , 2010
Project Number: 499 F
ti° * ri►
05-21-10
By the seal and signature here affixed, 0
I certify that the enclosed report was
accomplished by myself, and that I am ONAI.
currently a registered engineer of good NOTE: DRANK copy IS INSOMED WITH DIGIM D
standing in the State of Washington. SIGNATURE&DATE ORIGINAL SIGNED DRAWN IS
9 9 ARCHgVFD IN THE SIGNATURE FN(WI:RS OFFTCE.
ISLEY ALLYN PARCEL MICHAEL F. WNEK, P.E., PS
Drainage Report May 21, 2010
TABLE OF CONTENTS
VICINITY MAP 3
AERIAL PHOTO 4
CONTOUR MAP 5
ASSESSORS MAP 6
PROPERTY REPORTS/TAX DESCRIPTIONS 7
1. GENERAL................................................................................................................................................................................................8
a. Terminology.........................................................................................................................................................................................8
2. PROJECT DESCRIPTION........................................................................................................................................................................8
a. Type of Permits....................................................................................................................................................................................8
b. Size and Location of Project Site..........................................................................................................................................................8
C. Legal Description..................................................................................................................................................................................8
d. Proposed Land Use..............................................................................................................................................................................8
e. Proposed Site Improvements...............................................................................................................................................................8
f. Proposed Impervious Surfaces.............................................................................................................................................................8
g. Proposed Landscaping.........................................................................................................................................................................8
3. EXISTING CONDITIONS..........................................................................................................................................................................8
a. Topography..........................................................................................................................................................................................8
b. Land Cover...........................................................................................................................................................................................9
C. Land Cover/Land Use.........................................................................................................................................................................9
d. Offsite Drainage Onto Property............................................................................................................................................................9
e. Environmentally Sensitive Areas..........................................................................................................................................................9
f. Wells....................................................................................................................................................................................................9
g. Septic Systems....................................................................................................................................................................................9
h. Fuel Tanks...........................................................................................................................................................................................9
i. Soils.....................................................................................................................................................................................................9
j. Groundwater.........................................................................................................................................................................................9
k. Adjacent Drainage Facilities.................................................................................................................................................................9
I. Drainage Discharge Points...................................................................................................................................................................9
M. Relevant Reports.............................................................................................................................................................................9
4. DEVELOPED SITE DRAINAGE CONDITIONS......................................................................................................................................10
a. Proposed Land Cover.........................................................................................................................................................................10
b. Potential Storm Runoff Quantity&Quality Impacts............................................................................................................................10
C. Proposed Storm Collection&Conveyance........................................................................,................................................................10
d. Proposed Runoff Quantity Control......................................................................................................................................................10
e. Proposed Runoff Quality Control........................................................................................................................................................10
f. Drainage Mitigation Concept..............................................................................................................................................................10
g. Discharge Point..................................................................................................................................................................................10
5. WATERSHED DESCRIPTION...............................................................................................................................................................10
a. Contributing Basin..............................................................................................................................................................................10
b. Receiving Waters...............................................................................................................................................................................10
C. Project Basins....................................................................................................................................................................................11
6. DESCRIPTION OF UPSTREAM BASINS...............................................................................................................................................11
a. Sources of Runoff onto Project Site....................................................................................................................................................11
b. Existing Drainage&Erosion Problems...............................................................................................................................................11
7. DOWNSTREAM ANALYSIS(Level 1)....................................................................................................................................................11
a. Study Area.........................................................................................................................................................................................11
b. Resource Information.........................................................................................................................................................................11
c. Field Inspection..................................................................................................................................................................................11
d. Topography Map................................................................................................................................................................................11
e. Downstream Narrative........................................................................................................................................................................11
f. Structures&Channel.........................................................................................................................................................................11
g. Problem Areas...................................................................................................................................................................................11
8, SOILS REPORT.....................................................................................................................................................................................12
9. GEOTECHNICAL REPORT....................................................................................................................................................................12
10. HYDROLOGICAL ANALYSIS.............................................................................................................................................................12
a. Methodology.......................................................................................................................................................................................12
b. Infiltration Trench................................................................................................................................................................................12
C. Soils...................................................................................................................................................................................................12
d. Parameters.........................................................................................................................................................................................12
e. Runoff Volumes&Peak Discharges...................................................................................................................................................12
f. Bypass...............................................................................................................................................................................................12
11. BASIN MAPS.....................................................................................................................................................................................12
12. HYDRAULIC DESIGN COMPUTATIONS...........................................................................................................................................13
a. Piping.................................................................................................................................................................................................13
1
l ..( _ L 1 l .. .T M.d
ISLEY ALLYN PARCEL MICHAEL F. WNEK, P.E. PS
Drainage Report May 21, 2010
13. EROSION&SEDIMENTATION CONTROL DESIGN........................................................................................................................13
a. Erosion Control Objectives.................................................................................................................................................................13
b. Erosion Control/Temporary Water Quality Facilities.........................................................................................................................13
C. Re-vegetation Plan.............................................................................................................................................................................13
d. Soil Stability........................................................................................................................................................................................13
e. Computations for Conveyance...........................................................................................................................................................13
14. MAINTENANCE&OPERATION MANUAL........................................................................................................................................13
EXISTING CONDITION BASIN PLAN 14
DEVELOPED CONDITION BASIN PLAN 15
DRAINAGE AREA CALCULATIONS 16
WESTERN WASHINGTON HYDROLOGY MODEL PROJECT REPORT 8 PAGES
WATERSHED BASIN PLAN 25
WATERSHED EXHIBIT 26
2
ISLEY ALLYN PARCEL Michael F. Wnek, P.E., PS
Drainage Report May 21, 2010
VICINITY MAP
U
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W
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30
3
ISLEY ALLYN PARCEL Michael F. Wnek, P.E., PS
Drainage Report May 21, 2010
AERIALPHOTO
Mason Calmly Map Output Page Page 1 of 1
All Aerial
C. IEoi
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http-fnapmasoaco.nasonwaus�senlet'conesn.esnmap.Fsimap'SeniceName=amason_.. 402/2010
4
ISLEY ALLYN PARCEL Michael F. Wnek, P.E., PS
Drainage Report May 21, 2010
CONTOUR MAP
r
'f A
w
c�RUMST
Project Location
41,
f h
a
rW
CASE fNLE
'h
5
ISLEY ALLYN PARCEL Michael F. Wnek, P.E., PS
Drainage Report May 21, 2010
ASSESORS MAP
._«-___-__- 122205060008
122205063003 122205061006 1222(
122205064001 h2
121 O 122205062002 122205061004
122205063001 � 1222050590(
12220
4,4 U 122205062001 122205061001 122205060001
122205051
122205066005 122205059004
W
122205067005 SW 1 1222050590,
10020 ys `
&J 122205069001
122205070009
122205068002
7;
122209999M
122205067002 122205069002 122"5071008
� 1
122205070004
122205067001 �
122205071007 ~
Project Location 1zz2o5o71005
I I�
'71/4-4
)00 122205076000 122205071004 k�
7 122205069001 122205070001
122:
2 D DR 122205071001
122205075008
05010201 1122205075005
122205074001
122205073006
40 122205072009
6
ISLEY ALLYN PARCEL Michael F. Wnek, P.E., PS
Drainage Report May 21, 2010
122205068001 View Map
Owner Information
ISLEY,WILLIAM A&MELODY J 417 MADRONA WAY NE
IBAfNBRIDGE ISLAND WA 98110-1823
Taxpayer Information
ISLEY,WILLIAM A &MELODY J 417 MADRONA WAY NE
BAINBRIDGE ISLAND WA 98110-1823
Legal Description
ALLYN BLK: 68 LOT: 1 &VAC WHEELWRIGHT
Site Address
Reval Area �' 2 Field Sheet ? IFS 03267:68 �
Land Size*10.00 Land Use ? COMMERCIAL
Tax Code 215 Tax Code Description ? 11403 A P3 F5 L H
View Map
Owner Information
ISLEY, WILLIAM A&MELODY J 417 MADRONA WAY NE
BAINBRIDGE ISLAND WA 98110-1823
Taxpayer Information
ISLEY, WILLIAM A &MELODY J 417 MADRONA WAY NE
1BAINBRIDGE ISLAND WA 98110-1823
Legal Description
ALLYN BLK:68 LOT:2-10&VAC UHLMAN/WHEELWRIGHT
Site Address
Reval Area 2 Field Sheet ? IFS 03267:68-
Land Size*10.00 Land Use ? COMMERCIAL
Tax Code 215 Tax Code Description 1 403 A P3 F5 L H
Census Tract Click Here
NOTE:
At time of report, parcel is in the process of segregating BLK:68, LOT:2 as a separate tax parcel.
7
• I r � ,a� ,1 e may!-',
`•r.J rya.' wo x" .°" ,. "� � •�` �'._
ISLEY ALLYN PARCEL MICHAEL F. WNEK, P.E., PS
Drainage Report May 21, 2010
1. GENERAL
a. Terminology
Watershed -total area draining to a single outlet
Basin - a portion of a watershed delineated for separate study
Project Basin - project area requiring storm runoff mitigation
Upstream Basin - portion of watershed upstream of the Project Basin
Downstream Basin - portion of the watershed downstream of the Project Basin
2. PROJECT DESCRIPTION
a. Type of Permits
BUILDING PERMIT MASON COUNTY
GRADING PERMIT MASON COUNTY
b. Size and Location of Project Site
Parcel Size: 2.74 Acres
Project Size: <0.50 Acres
Clearing Area: <0.50 Acres
New Impervious: 0.20 Acres
Location: E Wheelwright St N & E. Lakeland Dr. (Mason County, Allyn)
c. Legal Description
Legal: Section 20, T22N, R1W, W.M.
Site Address: None
Assessor's Parcel Number: 122205068001, 122205068002
Zoning: Village Commercial
d. Proposed Land Use
Ground Floor= Commercial
Upper Floor= Residential
e. Proposed Site Improvements
Two buildings with access road
f. Proposed Impervious Surfaces
Road / Roof/ Sidewalk / Driveway:
g. Proposed Landscaping
Lawn & landscaping, typical for zone.
3. EXISTING CONDITIONS
a. Topography
The site slopes east. Maximum slopes are 10%.
8
ISLEY ALLYN PARCEL MICHAEL F. WNEK, P.E., PS
Drainage Report May 21, 2010
b. Land Cover
The property is approximately 75% grass covered; the remaining is bare ground/
dirt/gravel. See exhibit AERIAL PHOTO.
c. Land Cover/ Land Use
Project property— Vacant
General area - Suburban Residential/ Commercial
d. Offsite Drainage Onto Property
Roadside ditches & cross-culverts in Wheelwright& Lakeland roads transport upstream
runoff around the site. There is no off-site drainage onto the project.
e. Environmentally Sensitive Areas
Creeks, Lakes, Ponds, Wetlands— None
Ravines, Gulleys, Steep Slopes - None
Springs, Env. Sensitive Areas- None
No environmentally sensitive areas exist on the project or immediate vicinity.
f. Wells
There are no wells located on the site, public water is available.
g. Septic Systems
There are no septic systems located on the site, public sanitary sewer is available.
h. Fuel Tanks
None known
i. Soils
Soil Conservation Service maps for the area show the soil is typically found to be
"Sinclair (#59) gravelly sandy loam", belonging to the Hydrologic Group "C"
j. Groundwater
The soils information lists that there is a seasonal water table 3-feet below the surface
during the rainy season.
k. Adjacent Drainage Facilities
There are no known storm detention facilities within the watershed basin.
I. Drainage Discharge Points
Storm drainage from the project parcel flows easterly and discharges in the southeast
corner at along Lakeland Drive. Residential parcels immediately to the east
(downstream) are protected by a ditch in the vacated Sullivan right-of-way (currently
driveway access)that collects runoff from the project and routes it to Lakeland.
m. Relevant Reports
None
9
ISLEY ALLYN PARCEL MICHAEL F. WNEK, P.E., PS
Drainage Report May 21, 2010
4. DEVELOPED SITE DRAINAGE CONDITIONS
a. Proposed Land Cover
See 2.f. and 2.g.
b. Potential Storm Runoff Quantity & Quality Impacts
Quantity: Since the project will create greater than 5,000 square feet of impervious
area, runoff quantity controls must be considered.
Quality: Siltation of the storm runoff is possible during construction. Oil & sediment
contamination from vehicle drippings on the access and parking areas is possible after
the project is completed. Water quality must be considered.
c. Proposed Storm Collection & Conveyance
Stormwater runoff from the development will be collected by swales & curbs, and routed
by underground piping to the storm control facilities.
d. Proposed Runoff Quantity Control
Quantity control will be accomplished by an infiltration trench.
e. Proposed Runoff Quality Control
Water quality for the project will be accomplished by employing porous pavement for all
vehicle usage areas.
f. Drainage Mitigation Concept
Mitigation within the Lakeland right-of-way is accomplished by reducing the total
impervious area from the existing condition, and amending the soils of the remaining
pervious area. The building downspouts are tightlined directly to the infiltration trench.
Minor events will pass through the porous pavement to provide water quality. Larger
events will be collected by the project storm sewer system and directed to the infiltration
trench. The infiltration trench is sized for all events, for all surface area, within the
project parcel
g. Discharge Point
The development discharge point will be to the existing location, see paragraph 3.1.; but
only as an overflow from the infiltration trench is severe conditions.
5. WATERSHED DESCRIPTION
a. Contributing Basin
The site is part of a larger watershed that drains directly into Case Inlet via existing
ditches, catch basins and pipes. See exhibits WATERSHED EXHIBIT, WATERSHED
BASIN PLAN.
b. Receiving Waters
All runoff flows to Case Inlet.
10
— it _ ..; i-. .i: � r .e. ..:`1r� -.a ifi � 1�. ii• � ... r .. J
� M
ry
ISLEY ALLYN PARCEL MICHAEL F. WNEK, P.E., PS
Drainage Report May 21, 2010
c. Project Basins
The developed parcel is used as the limits of the project basin.
6. DESCRIPTION OF UPSTREAM BASINS
a. Sources of Runoff onto Project Site
Minimal, see Section 3.d.
b. Existing Drainage & Erosion Problems
There are no obvious drainage or erosion problems within the project parcel or the
upstream basin.
7. DOWNSTREAM ANALYSIS (Level 1)
a. Study Area
All storm runoff for the vicinity eventually flows to Case Inlet. The limits of the
watershed are shown on exhibit WATERSHED BASIN PLAN. The watershed is mostly
urbanized; watershed runoff is not collected into a stream but transported in roadside
ditches and storm sewers.
b. Resource Information
Unknown
c. Field Inspection
A general inspection of the area was performed to delineate flow patterns and structures
in the area surrounding the site and the contributing watershed. The downstream route
is shown on exhibit WATERSHED EXHIBIT.
d. Topography Map
See CONTOUR MAP, see WATERSHED BASIN PLAN..
e. Downstream Narrative
Runoff from the site flows via ditches and culverts to an 18" culvert that runs across E
State Route Hwy 3 to an existing catch basin. From there, runoff collects in another
catch basin via an existing 18" culvert, to be released through an 18" CMP into Case
Inlet.
f. Structures & Channel
See paragraph 7.e.
g. Problem Areas
The downstream route was inspected during a rain event on 05-20-07. Total rainfall for
the day was reported as 1.48 inches. No inadequacies in the downstream storm sewer
were witnessed during this rain event, however the rainfall that day was less than the 6-
month event.
11
ISLEY ALLYN PARCEL MICHAEL F. WNEK, P.E., PS
Drainage Report May 21, 2010
8. SOILS REPORT
see: "Soils Report for Storm Drainage"
Michael F. Wnek, P.E., PS
May 17, 2010
9. GEOTECHNICAL REPORT
None warranted.
10. HYDROLOGICAL ANALYSIS
a. Methodology
The hydrological analysis is based on continuous simulation using the Western
Washington Hydrology Model, version 3.
b. Infiltration Trench
The model calculates the infiltration trench as a vault. In order to extrapolate the data to
a rock filled trench, the "depth" & 'overflow riser" data must be multiplied by a factor of
3; assuming the rock filled trench is 2/3 rock & 1/3 void (storage).
c. Soils
Sinclair: Group C, glacial till.
d. Parameters
The infiltration trench is located below the access road which will be constructed of
porous pavement. The infiltration trench is designed to mitigate the entire project area.
For calculations, the porous pavement is considered impervious area; since the porous
pavement is constructed on grades steeper than 2%.
The project will remove 0.04 acres of existing pavement at the intersection of
Wheelwright & Lakeland roads. This area offsets the new impervious area outside of
the project basin (0.01 acre sidewalk, 0.2 acre road approach).
e. Runoff Volumes & Peak Discharges
Calculations are in exhibit WESTERN WASHINGTON HYDROLOGY MODEL
PROJECT REPORT.
f. Bypass
All project storm runoff can be captured and routed through the mitigation system.
There will be no un-mitigated runoff from the project.
11. BASIN MAPS
The existing condition & developed condition basins are the same ("Project Basin").
See exhibits EXISTING CONDITION BASIN PLAN, DEVELOPED CONDITION BASIN
PLAN.
12
ISLEY ALLYN PARCEL MICHAEL F. WNEK, P.E., PS
Drainage Report May 21, 2010
12. HYDRAULIC DESIGN COMPUTATIONS
a. Piping
6-inch piping (n=0.012 & s=1.5%) is adequate to handle the entire developed condition
flow.
13. EROSION & SEDIMENTATION CONTROL DESIGN
a. Erosion Control Objectives
To prevent sediments from leaving the project site to adjacent properties or downstream
channels.
b. Erosion Control /Temporary Water Quality Facilities
The following temporary erosion control facilities will be used for construction:
Construction Entrance
Check Dams
Filter Fabric Fence
The project size does not warrant additional measures.
c. Re-vegetation Plan
The pervious areas will be re-vegetated with lawn & landscaping after building
construction. All vegetative areas will be enhanced with 3-inches of additional compost,
tilled to a 12-inch depth.
d. Soil Stability
In general, no slopes steeper than 2:1 will be required for the project. Gravity retaining
walls may be required at some locations; walls over 4' in vertical height will require
separate engineering design and building permit.
e. Computations for Conveyance
The types of erosion control facilities proposed for this project do not require any
engineering calculations for conveyance.
14. MAINTENANCE & OPERATION MANUAL
All temporary erosion control facilities will be removed from the site at the completion of
construction. The storm water features on the site will require periodic inspection and
annual maintenance.
13
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ISLEY ALLYN PARCEL Michael F. Wnek, P.E., PS
Drainage Report May 21, 2010
EXISTING CONDITION BASIN PLAN
SCALE
EXITI G PASIN
ProjeO BOin
02x /
I I I 7 ( I
14
ISLEY ALLYN PARCEL Michael F. Wnek, P.E., PS
Drainage Report May 21, 2010
DEVELOPED CONDITION BASIN PLAN
:.. . .�,
try << �� IL / 1�
SCAff-
�/ // / � /(; �/ J PROPOSS,Ep�//�7 6
PROPOS�F / /
l fMISE iFR.dI�Sr�'�
/IM / V1O --Build'n2 /
QriveWa -2tm- l
/001 /ac s II PROPOSED
4WD 8/sf i I! / IMPERVIOUS
PROPOS
IMPERVIOUS ` / /� / I ( , Sidewalk Proj.
( 0.02 acres
0.01 Drive a / -3$3.35 sf
1
/
1O15OSED�
IMPERVIOUS
ave. Pri.
eO�OS3*p ( �� I ( / / �, 1 —— 0.07 act
IMPEi IOUsy/ I 226.87 sf
Buildin
0.04 acres
1760.00 sf
PROPOSED PQP ED I I \
IMPEOk�S /
IMPERVIOUS �
SIDEWALK R-W Por. Pavement�R-w
0.01 acres 0.02 acres
545.97 sf 992.83 sf
15
ISLEY ALLYN PARCEL Michael F. Wnek, P.E., PS
Drainage Report 5/21/2010
DRAINAGE AREA CALCULATIONS
PROJECT BASIN Area Area
Impervious sf acre
Por. Pave. Proj. 3,227 0.07
Sidewalk Proj. 783 0.02
Building-1 1,760 0.04
Driveway-1 578 0.01
Building-2 1,920 0.04
Driveway-2 466 0.01
subtotal= 8,734 0.20
Previous
Lawn-Landscape 1,721 0.04
subtotal= 1,721 0.04
total= 10,454 0.24
R-W BASIN
Impervious Removed
Ex Asphalt Fillet 1,742 0.04
subtotal= 1,742 0.04
Impervious Added
Sidewalk R-W 546 0.01
Por. Pavement R-W 993 0.02
subtotal= 1,539 0.04
16
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ISLEY ALLYN PARCEL Michael F. Wnek, P.E., PS
Drainage Report May 21, 2010
Western Washington Hydrology Model
PROJECT REPORT
Project Name: ISLEY-B
Site Address:
City ALLYN
Report Date 5/21/2010
Gage Quilcene
Data Start 1955/10/01
Data End 1999/09/30
Precip Scale: 1.11
WWHM3 Version:
PREDEVELOPED LAND USE
Name EXIST
Bypass: No
GroundWater: Nn
Pervious Land Use Acres
C, Forest, Flat .24
Impervious Land Use Acres
Element Flows To:
Surface Interflow Groundwater
Name DEVELOPED
Bypass: No
GroundWater: No
Pervious Land Use Acres
C, Lawn, Mod .04
Impervious Land Use Acres
ROOF TOPS FLAT 0.08
DRIVEWAYS MOD 0.1
SIDEWALKS FLAT 0.02
Element Flows To:
Surface Interflow Groundwater
Vault ] , Vault ] ,
17
ISLEY ALLYN PARCEL Michael F. Wnek, P.E., PS
Drainage Report May 21, 2010
Name Vault 1
Width 10 ft.
Length 70 ft.
Depth: 0.5ft.
Infiltration On
Infiltration rate : 2
Infiltration saftey factor 0.25
Discharge Structure
Riser Height: 0.4 ft.
Riser Diameter: 6 i.n.
Element Flows To:
Outlet 1 Outlet 2
Vault Hydraulic mable
Stage(ft) Area(acr) Volume(acr-ft) Dschrg(cfs) Infilt(cfs)
0.000 0.016 0.000 0.000 0.000
0.006 0.01.6 0.000 0.000 0.008
0.011 0.016 0.000 0.000 0.008
0.017 0.016 0.000 0.000 0.008
0.022 0.016 0.000 0.000 0.008
0.028 0.016 0.000 0.000 0.008
0.033 0.016 0.001 0.000 0.008
0.039 0.016 0.001 0.000 0.008
0.044 0.016 0.001 0.000 0.008
0.050 0.016 0.001 0.000 0.008
0.056 0.016 0.001 0.000 0.008
0.061 0.016 0.001 0.000 0.008
0.067 0.016 0.001 0.000 0.008
0.072. 0.0.16 0.001 0.000 0.008
0.078 0.016 0.001 0.000 0.008
0.083 0.016 0.001 0.000 0.008
0.089 0.016 0.001 0.000 0.008
0.094 0.016 0.002 0.000 0.008
0.100 0.016 0.002 0.000 0.008
0.106 0.016 0.002 0.000 0.008
0.111 0.016 0.002 0.000 0.008
0.117 0.016 0.002 0.000 0.008
0.122 0.016 0.002 0.000 0.008
0.128 0.016 0.002 0.000 0.008
0.133 0.016 0.002 0.000 0.008
0.139 0.016 0.002. 0.000 0.008
0.144 0.016 0.002 0.000 0.008
0.150 0.016 0.002 0.000 0.008
0.156 0.016 0.002 0.000 0.008
0.161 0.016 0.003 0.000 0.008
0.167 0.016 0.003 0.000 0.008
0.172 0.016 0.003 0.000 0.008
0.178 0.016 0.003 0.000 0.008
0.183 0.016 0.003 0.000 0.008
0.189 0.016 0.003 0.000 0.008
0.194 0.016 0.003 0.000 0.008
0.200 0.016 0.003 0.000 0.008
0.206 0.016 0.003 0.000 0.008
0.211 0.016 0.003 0.000 0.008
0.217 0.016 0.003 0.000 0.008
18
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ISLEY ALLYN PARCEL Michael F. Wnek, P.E., PS
Drainage Report May 21, 2010
MITIGATED LAND USE
ANALYSIS RESULTS
Flow Frequency Return Periods for Predeveloped. POC #1
Return Period Flow(cfs)
2 year 0.048714
5 year 0.06868
10 year 0.084064
25 year 0.106147
50 year 0.124641
100 year 0.144992
Flow Frequency Return Periods for Mitigated. POC #1
Return Period Flow(cfs)
2 year 0
5 year 0
10 year 0
25 year 0
50 year 0
100 year 0
Yearly Peaks for Predeveloped and Mitigated. POC #1
Year Predeveloped Mitigated
1957 0.215 0.000
1958 0.045 0.000
1959 0.069 0.000
1960 0.074 0.082
1961 0.047 0.000
1962 0.060 0.000
1963 0.051 0.000
1964 0.045 0.000
1965 0.034 0.000
1966 0.024 0.000
1967 0.119 0.000
1968 0.053 0.045
1969 0.050 0.000
1970 0.042 0.000
1971 0.048 0.000
1972 0.067 0.000
1973 0.053 0.000
1974 0.050 0.000
1975 0.066 0.045
1976 0.053 0.000
1977 0.060 0.000
1978 0.037 0.000
1979 0.043 0.000
1980 0.042 0.000
1981 0.051 0.000
1982 0.042 0.000
1983 0.044 0.000
1984 0.072 0.130
1985 0.028 0.000
1986 0.040 0.000
20
ISLEY ALLYN PARCEL Michael F. Wnek, P.E., PS
Drainage Report May 21, 2010
1987 0.043 0.000
1988 0.052 0.000
1989 0.040 0.000
1990 0.026 0.000
1991 0.032 0.000
1992 0.053 0.000
1993 0.050 0.049
1994 0.034 0.000
1995 0.079 0.076
1996 0.048 0.000
1997 0.057 0.040
1998 0.051. 0.000
1999 0.046 0.000
2000 0.090 0.075
Ranked Yearly Peaks for Predeveloped and Mitigated. POC #1
Rank Predeveloped Mitigated
1 0.2149 0.1299
2 0.11.91. 0.0820
3 0.0904 0.0757
4 0.0791 0.0747
5 0.0740 0.0487
6 0.0724 0.0450
7 0.0691 0.0449
8 0.0674 0.0401
9 0.0658 0.0000
10 0.0597 0.0000
11 0.0596 0.0000
12 0.0572 0.0000
13 0.0534 0.0000
14 0.0533 0.0000
15 0.0530 0.0000
16 0.0529 0.0000
17 0.0525 0.0000
18 0.0509 0.0000
19 0.0507 0.0000
20 0.0505 0.0000
21 0.0503 0.0000
22 0.0497 0.0000
23 0.0495 0.0000
24 0.0482 0.0000
25 0.0482 0.0000
26 0.0474 0.0000
27 0.0459 0.0000
28 0.0452 0.0000
29 0.0446 0.0000
30 0.0442 0.0000
31 0.0433 0.0000
32 0.0427 0.0000
33 0.0421 0.0000
34 0.041.6 0.0000
35 0.0415 0.0000
36 0.0396 0.0000
37 0.0396 0.0000
38 0.0373 0.0000
21
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ISLEY ALLYN PARCEL Michael F. Wnek, P.E., PS
Drainage Report May 21, 2010
0.1236 1 1 100 Pass
0.1246 1 1 100 Pass
Water Quality BMP Flow and Volume for POC 1.
On-line facility volume: 0 acre-feet
On-line facility target flow: 0 cfs.
Adjusted for 15 min: 0 cfe.
Off-line facility target flow: 0 cfs.
Adjusted for 15 min: 0 cfs.
Perind and Impind Changes
No changes have been made.
This program and accompanying documentation is provided 'as-is' without warranty of any kind. The
entire risk regarding the performance and results of this program is assumed by the user. Clear Creek
Solutions and the Washington State Department of Ecology disclaims all warranties, either expressed
or implied, including but not limited to implied warranties of program and accompanying documentation.
In no event shall Clear Creek Solutions and/or the Washington State Department of Ecology be liable
for any damages whatsoever (including without limitation to damages for loss of business profits, loss
of business information, business interruption, and the like) arising out of the use of, or inability
to use this program even if Clear Creek Solutions or the Washington State Department of Ecology has
been advised of the possibility of such damages.
24
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ISLEY ALLYN PARCEL Michael F. Wnek, P.E., PS
Drainage Report May21, 2010
WATERSHED EXHIBIT (2/2)
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LEGEND
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26
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