HomeMy WebLinkAboutSWP272808 t T
BRIERE PLAT
King County, Washington
Level H Drainage Analysis
Prepared For:
J. Briere Construction
Prepared By:
Pacific Engineering Design, Inc. �✓�`'
October 29, 1998 PEDI Job No. 98016
T
LEVEL II DRAINAGE ANALYSIS
BRIERE PLAT
KING COUNTY, WASHINGTON
December 18, 1998
PREPARED FOR
J. BRIERE CONSTRUCTION
23205 SE 192ND STREET
MAPLE VALLEY, WA 98038
(425) 432-7582
PREPARED BY
PACIFIC ENGINEERING DESIGN, INC.
130 ANDOVER PARK EAST, SUITE 300
SEATTLE, WASHINGTON 98188
(206) 431-7970
WAS11
Q
� z
�. 12701
12. NA
EXPIRES: SEPT. 5, 1999
1 T
Pagel of 2
King County Building and Land Development Division
TECHNICAL INFORMATION REPORT (TIR) WORKSHEET
ARtj- � - PROJECT OW EWAN
. .
ProjectOwner Mr . Gerald Briere "Location
e Briere Plat
Address ?3 2 n� S L 1 Q 2 n d t7 �IaT 1 e V a 11 e
Phone 499-4'�9_79A2 WA. 98038 Township 2 3 N
Project Engineer John Newell Range 5E
Company Pacific Engi n Section 3
ring D�yi can, I cprojectSize 2 - 28 AC
Address Phone 130 Andover Park E, Ste 30 U stream Drainage Basin Size 0 AC
206-4'11 -7970 Seattle , WA 1981189
• •
® Subdivision 0 DOF/G HPA E::] Shoreline Management
0 Short Subdivision 0 COE 404 ED Rockery
Grading 0 DOE Dam Safety ® Structural Vaults
Commercial FEMA Floodplain 0 Other
CJ Other COE Wetlands HPA
Community Renton
Drainage Basin Honey Creek Drainage Basin
RISITICS
River Floodplain
Stream Wetlands
Critical Stream Reach 0 Seeps/Springs
Depressions/Swales C] High Groundwater Table
Lake 0 Groundwater Recharge
Steep Slopes Other
Lakeside/Erosion Hazard
•
Soil Type Slopes Erosion Potential Erosive Velocities
Alderwood (AgC) 0-5% Low Low
0 Additional Sheets Attatched
:/90
Page 2 of 2
King County Building and Land Development Division
TECHNICAL INFORMATION REPORT (TIR) WORKSHEET
REFERENCE LIMITATION/SITE CONSTRAINT
[� Ch.4-Downstream Analysis
0
0
0
0 Additional Sheets Attatched
PART9. ESC REQUIREMENTS
MINIMUM ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS
DURING CONSTRUCTION FOLLOWING CONSTRUCTION
0 Sedimentation Facilities ® Stabilize Exposed Surface
® Stabilized Construction Entrance EK Remove and Restore Temporary ESC Facilities
Perimeter Runoff Control Ox Clean and Remove All Silt and Debris
0 Clearing and Grading Restrictions Ensure Operation of Permanent Facilities
Cover Practices 0 Flag Limits of NGPES
Fx Construction Sequence 0 Other
0 Other
PARTIO SURFACE WATER SYSTEM-
0 Grass Lined Channel 0 Tank 0 Infiltration Method of Analysis
® Pipe System ® Vault 0 Depression SBUH/SCS
Open Channel Energy Dissapator Flow Dispersal Compensation/Mitigation
Dry Pond 0 Wetland 0 Waiver of Eliminated Site Storage
Wet Pond 0 Stream 0 Regional Detention
Brief Description of System Operation A piped conveyonce system will be discharged into
a detention vault which will discharge into a biofiltration swale prior to
discharge into the downstream dr s toT
Facility Related Site Limitations �c itionjIghee Attatched
Reference Facility Limitation
..:PART,Il 'SliAiU6irORALAN'ALYSIS tilt
7FMx�
Drainage Easement
0 Cast in Place Vault 0 Other Access Easement
Retaining Wall 0 Native Growth Protection Easement
Rockery>4'High Tract
E:] Structural on Steep Slope 0 Other
I or a civil engineer under my supervision have visited the site. Actual
site conditions as observed were incorporated into this worksheet and the f
attatchments. To the best of my knowledge the information provided `•
here is accurate. sy�ao.r* il-1r_ i
1/90
TABLE OF CONTENTS
I. PROJECT NARRATIVE............................................................................................
II. DRAINAGE REPORT................................................................................................
III. LEVEL it OFFSITE ANALYSIS.................................................................................
EXISTING CONDITIONS ..................................................................................................
DEVELOPED CONDITIONS .............................................................................................
IV. ..................................................................................................................................
V. ...................................................................................................................................
VI. ..................................................................................................................................
VII. ..................................................................................................................................
I. PROJECT NARRATIVE
Project Narrative—Briere Preliminary Plat
The Briere Preliminary Plat is located on a parcel of land encompassing 2.28± acres of
land approximately 170 feet east of the NE 18th St./Duvall Ave NE intersection. The site
is vacant except for an encroaching carport and two small sheds and is zoned Residential
- 8 Dwelling units per acre (R-8). The surrounding properties consist of vacant property
to the north, Plat of Summerwind to the east, Parkway Townhomes (condominiums) on
the south and single family homes on large lots to the west.
The site is mostly cleared with some small trees and brush adjacent to the exterior
property lines on the south and east with the remainder of the site in pasture grasses. The
parcel slopes gently to the north and east and the present drainage pattern consist'of
sheet flow. Soils on site have been classified by the Soil Conservation Service as
Alderwood Series (AgC) slopes of 0-5% and Hydrologic Group C. No trees removal is
being proposed for construction of the plat infrastructure.
The proposal is to subdivide the parcel through the platting process into 12 single-family
residential lots with a public street and utilities serving each of the new lots. Building
height will be limited to two stories - 30' dwellings and 15' for detached accessory
structure.
Offsite improvements will consist of additional pavement, curbs, gutters, and sidewalks
along the existing NE 18th St. from the parcel to the intersection of NE 18th St. with
Duvall Ave NE. Utility lines consisting of franchised utilities (power, gas, telephone and
cable T.V.), sanitary sewer, water mains and storm drainage will also be extended within
the present NE 18th St. corridor to serve this development. In addition a drainage
easement for the bioswale connecting the proposed vault outfall to the offsite drainage
corridor in Summerwind is being proposed across offsite property to the north. The
owner of this property has been consulted regarding this easement and has tentatively
agreed to grant it.
The estimated plat construction cost is $360,000 and the estimated fair market value of
the 12 finished lots is $720,000. These numbers are only estimates at this time and are
subject to revision.
Due to the nature of the site the installation of the road and utility infrastructure will
involve minimum excavation and embankments. At this time it is estimated the quality
of material in fills or excavation will be less than 500 c.y. Additional yard fills may be
needed when homes are constructed on each lot; however, the actual building plans have
not been finalized so the amount of yard fill, if any, cannot be assessed. This will be a
part of the building permit submitted at a later date.
The portion of the site containing the public road and utilities will be dedicated to the
City of Renton through the platting process, as public property. Utility lines across
lots/private property will be within easements.
II. DRAINAGE REPORT
DRAINAGE REPORT
The site is comprised of 2.28 acres of land near Duvall Avenue NE and NE 18th Street in Renton,
Washington. Except for two sheds and an encroaching carport, the site is vacant with some
scattered trees and brush.
The projects consists of off-site utility and roadway improvements to NE 18th Street and
construction of onsite plat improvements which include sanitary sewer, storm drainage, water
facilities, street pavement, street lighting, detention vault and a water quality biofiltration swale.
After construction of roads and utilities the parcel will be subdivided in 12 lots.
Drainage flows are generally directed towards the northeast into an existing off-site drainage
course flowing southerly into Tract "A" of the Summerwind Div. 4 Plat. The open drainage
course discharges into a piped conveyance system flowing south under Field Avenue NE. The
project will comply with Core Requirements 1-5. None of the Special Requirements 1-12 appear
to apply to this project.
Preliminary drainage calculations to size a storm drainage detention vault were done based on the
SBUH hydrograph method. Adjusting for a small by-pass area, the pre-developed 2, 10 and 100-
year/24 hr. storm events were matched with the post-developed 2, 10 and 100-year/24 hr. events
to determine the required storm detention vault volume (see attached calculations).
Preliminary biofiltration swale calculations were done based on the 2-year/24 hr. pre-developed
discharge rate (see attached calculations). A wetpond is not required on this project due to the
traveled impervious area being less than 1 acre.
Existing Rates: _ (Ex. - Bypass) + (Ex Bypass)
2 yr. (existing) =0.263 + 0.008 = 0.271 cfs
10 yr. (existing) =0.531 + 0.015 = 0.546 cfs
100 yr. (existing) = 0.888 + 0.025 = 0.913 cfs
Release Rates = (Ex - Bypass) + (Ex Bypass) - Bypass Release
2 yr. (Dev) = 0.271 - 0.020 = 0.251 cfs
10 yr. (Dev) = 0.546 - 0.029 = 0.517 cfs
100 yr. (Dev) = 0.913 - 0.039 = 0.874 cfs
Core Requirements:
1. Discharge at the Natural Locations:
The project slopes naturally to the north and east. The proposal discharge point of the
bioswale is at the northeast property corner. Therefore this core requirement will be
satisfied.
2. Off-Site Analysis:
A Level 2 Analysis of the offsite drainage basin has been done as required by the City of
Renton and is part of the Drainage Report. The analysis showed no downstream drainage
capacity of erosion problems.
3. Runoff Control: "
The proposal will utilize an underground cement concrete detention vault with metering
orifices to limit the developed conditions peak rates of runoff to the predevelopment peak
rates for the 2 year, 10 year, and 100 year design storm.
4. Conveyance System:
The conveyance system will be analyzed and constructed for the proposed development.
The offsite drainage system has been reviewed under the Level 2 analysis and found to be
adequate for this development.
5. Temporary Erosion and Sedimentation Control:
The construction plans for the site improvements will contain a grading, clearing and
erosion/sedimentation control plans. These plans shall include BMP's which will
minimize erosion and sedimentation onto adjacent properties.
Special Requirements:
Special requirements 1-10 do not apply to this proposal. Requirement 11 (Geotechnical analysis
and Report) and Requirements 12 (Soils Analysis and Report) have been waived by city staff.
KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL
1.2 CORE REQUIREMENTS
The seven Core Requirements are:
(1) Discharge at the Natural Location. The discharge from a proposed project site must occur at
the natural location.
(2) Off-Site Analysis. All proposed projects must identify the upstream tributary drainage area and
perform a downstream analysis. Levels of analysis required depend on the problems identified
or predicted. At a minimum, a Level 1 analysis must be submitted with the initial permit
application.
(3) Runoff Control. Proposed projects must provide runoff controls to limit the developed
conditions peak rates of runoff to the pre-development peak rates for specific design storm
events based on the runoff from defined existing site conditions, and install biofiltration
measures.
(4) Conveyance System. All conveyance systems for proposed projects must be an,aJyzed,
designed and constructed for existing tributary off-site runoff and developed on-site runoff from
the proposed project.
(5) Temporary Erosion and Sedimentation Control. All projects that require engineered drainage
plans shall provide Temporary Erosion and Sedimentation Control (TESC) measures that
minimize the transport of sediment to drainage facilities, water resources, and adjacent
properties.
(6) Maintenance and Operation. Maintenance of all drainage facilities constructed or modified by a
proposed project is the responsibility of the property owner (see Maintenance Requirements for
Privately Maintained Drainage Facilities in Appendix A), except King County may assume
maintenance of drainage facilities constructed for formal Plat Subdivisions, planned unit
developments, and some Short Plat Subdivisions two years after construction approval.
(7) Bonds and Liability. All drainage facilities for proposed projects (except drainage stub-out
connections, downspout roof drain infiltration systems and downspout dispersion systems for
single-family residential lots) must be constructed in conformance with the bond and liability
requirements of King County Code 9.04.100.
1 .2-1 11/94
KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL
1.3 SPECIAL REQUIREMENTS
In addition to the seven Core Requirements, twelve Special Requirements may apply to a proposed
project. Each set of requirements below is preceded by the conditions in which the requirements apply
its "threshold." Most thresholds can be assessed and the special requirements determined in advance of
formal engineering plan preparation. Other thresholds may require a special study before a
determination can be made as to the application of a Special Requirement to a proposed project.
The twelve Special Requirements are:
(1) Critical Drainage Areas
(2) Compliance with an Existing Master Drainage Plan
(3) Conditions requiring a Master Drainage Plan
(4) Adopted Basin or Community Plans
(5) Special Water Quality Controls
(6) Coalescing plate oil/water separators
(7) Closed Depressions
(8) Use of Lakes, Wetlands or Closed Depressions for Runoff Control
(9) Delineation of the 100 year Floodplain.
(10) Flood Protection Facilities for Type 1 and Type 2 Streams
(11) Geotechnical Analysis and Report
(12) Soils Analysis and Report
F 1
1.0/27/98 11 :44 :2 am Pacific Engineering Design Inc page
BRIERS PLAT - JOB NO .98016
DRAINAGE CALCULATIONS
BASIN SUMMARY
BASIN ID: DBY02 NAME: 2-YR . DEV . BYPASS
SBUH METHODOLOGY
TOTAL AREA . . . . . . . = 0 .04 Acres BASEFLOWS: 0 .00 cfs
RAINFALL TYPE . . . . KC24HR DERV IMP
PRECIPITATION . . . . : 2 . 10 inches AREA . . : 0 .00 Acres 0 .04 Acr
TIME INTERVAL . . . . : 10 .00 min CN . . . . : 85 .00 98 .00
TC . . . . 5 .00 min 5 .00 min
ABSTRACTION COEFF : 0 .20
PEAK RATE : 0 .02 cfs VOL : 0 .01 Ac-ft TIME : 470 min
BASIN ID: DBY10 NAME : 10-YR . DEV . BYPASS
SBUH METHODOLOGY
TOTAL_ AREA . . . . . . . : 0 .04 Acres BASEFLOWS: 0 .00 cfs
RAINFALL TYPE . . . . : KC24HR PERV IMP
PRECIPITATION . . . . : 2 .95 inches AREA . . : 0 .00 Acres 0 .04 Acr
TIME INTERVAL . . . . : 10 .00 min CN . . . . : 85 .00 98 .00
TC . . . . : 5 .00 min 5 .00 min
ABSTRACTION COEFF: 0 .20
PEAK RATE : 0 .03 cfs VOL : 0 .01 Ac-ft TIME : 470 min
BASIN ID : DBY100 NAME: 100-YR . DEV . BYPASS
SBUH METHODOLOGY
TOTAL AREA . . . . . . . : 0 .04 Acres BASEFLOWS: 0 .00 cfs
RAINFALL TYPE . . . . : KC24HR PERV IMP
PRECIPITATION . . . . : 3 .95 inches AREA . . : 0 .00 Acres 0 .04 Acr
TIME INTERVAL . . .. : 10 .00 min CN . . . . .. 85 .00 98 .00
TC . . . . 5 .00 min 5 .00 min
ABSTRACTION COEFF : 0 .20
PEAK RATE : 0 .04 cfs VOL : 0 .01 Ac-ft TIME: 470 min
BASIN ID : EBY02 NAME: 2-YR . EXISTING BYPASS
SBUH METHODOLOGY
TOTAL AREA . . . . . . . : 0 .04 Acres BASEFLOWS: 0 .00 cfs
RAINFALL TYPE . . . . : KC24HR PERV IMP
PRECIPITATION . . . . : 2 .10 inches AREA . . : 0 .04 Acres 0 .00 Ac.
TIME INTERVAL . . . . : 10 .00 min CN . . . . : 85 .00 98 .00
TC . . . . • 5 .00 min 5 .00 min
ABSTRACTION COEFF: 0 .20
PEAK RATE : 0 .01 cfs VOL : 0 .00 Ac-ft TIME : 480 min
10/27/98 11 :44 : 2 am Pacific Engineering Design Inc page
BRIERS PLAT -- JOB NO .98016
DRAINAGE CALCULATIONS
BASIN SUMMARY
BASIN ID: EBY10 NAME: 10-YR . EXISTING BYPASS
SBUH METHODOLOGY
TOTAL AREA . . . . . . . : 0 .04 Acres BASEFLOWS: 0 .00 cfs
RAINFALL TYPE . . . . : KC24HR PERV IMP
PRECIPITATION . . . . : 2 .95 inches AREA . . : 0 .04 Acres 0 .00 ACT-
TIME INTERVAL . . . . : 10 .00 min CN . . . . : 85 .00 98 .00
TC . . . . . 5 .00 min 5 .00 min
ABSTRACTION COEFF : 0 .20
PEAK RATE : 0 .02 cfs VOL : 0 .00 Ac-ft TIME : 470 min
BASIN ID : EBY100 NAME: 100-YR . EXISTING BYPASS
SBUH METHODOLOGY
TOTAL AREA . . . . . . . : 0 .04 Acres BASEFLOWS: 0 .00 cfs
RAINFALL TYPE . . . . : KC24HR PERV IMP
PRECIPITATION . . . . : 3 .95 inches AREA . . : 0 .04 Acres 0 .00 Ac
TIME INTERVAL . . . . : 10 .00 min CN . . . . : 85 .00 98 .00
TC . . . . 5 .00 min 5 .00 min
ABSTRACTION COEFF : 0 .20
PEAK RATE : 0 .03 cfs VOL : 0 .01 Ac-ft TIME : 470 min
10/27/98 11 :43: 14 am Pacific Engineering Design Inc page
BRIERE PLAT - JOB NO .98016
DRAINAGE CALCULATIONS
BASIN SUMMARY
BASIN ID: DEV02 NAME : 2-YR . DEV LESS BYPASS
SBUH METHODOLOGY
TOTAL AREA . . . . . . . = 2 .24 Acres BASEFLOWS: 0 .00 cfs
RAINFALL TYPE . . . . : KC24HR PERV IMP
PRECIPITATION . . . . : 2 . 10 inches AREA . . : 1 .16 Acres 1 .08 Acr,
TIME INTERVAL . . . . : 10 .00 min CN . . . . : 86 .00 98 .00
TC . . . . • 5 .00 min 5 .00 min
ABSTRACTION COEFF : 0 .20
PEAK RATE : 0 .83 cfs VOL : 0 .26 Ac-ft TIME : 470 min
BASIN ID : DEV10 NAME: 10-YR . DEV LESS BYPASS
SBUH METHODOLOGY
TOTAL AREA . . . . . . . : 2 .24 Acres BASEFLOWS: 0 .00 cfs
RAINFALL TYPE . . . . : KC24HR PERV IMP
PRECIPITATION . . . . : 2 .95 inches AREA . . : 1 .16 Acres 1 .08 Acr
TIME INTERVAL . . . . : 10 .00 min CN . . . . . 86 .00 98 .00
TC . . . . 5 .00 min 5 .00 min
ABSTRACTION COEFF: 0 .20
PEAK RATE : 1 .32 cfs VOL : 0 .40 Ac-ft TIME : 470 min
BASIN ID: DEV100 NAME: 100-YR . DEV LESS BYPASS
SBUH METHODOLOGY
TOTAL AREA . . . . . . . : 2 .24 Acres BASEFLOWS: 0 .00 cfs
RAINFALL TYPE . . . . : KC24HR PERV IMP
PRECIPITATION . . . . : 3 .95 inches AREA . . : 1 .16 Acres 1 .08 Acr
TIME INTERVAL . . . . : 10 .00 min CN . . . . : 86 .00 98 .00
TC . . . . 5 .00 min 5 .00 min
ABSTRACTION COEFF : 0 .20
PEAK RATE : 1 .92 cfs VOL : 0 .58 Ac-ft TIME : 470 min
BASIN ID : EX02 NAME: 2-YR . EXISTING LESS BYPASS
SBUH METHODOLOGY
TOTAL AREA . . . . . . . : 2 .24 Acres BASEFLOWS: 0 .00 cfs
RAINFALL TYPE . . . . : KC24HR PERV IMP
PRECIPITATION . . . . : 2 .10 inches AREA . . : 2 .24 Acres 0 .00 Acr
TIME INTERVAL . . . . : 10 .00 min CN . . . . : 85 .00 98 .00
TC . . . . : 36 .46 min 36 .46 min
ABSTRACTION COEFF : 0 .20
TcReach - Sheet L : 300 .00 ns:0 .1500 p2yr : 2 .10 s:0 .0122
TcReach - Shallow L: 70 .00 ks: 11 .00 s : 0 .0122
PEAK RATE : 0 .26 cfs VOL: 0 .16 Ac-ft TIME : 490 min
10/27/98 11 :43: 14 am Pacific Engineering Design Inc page
BRIERE PLAT - JOB NO .98016
DRAINAGE CALCULATIONS
BASIN SUMMARY
BASIN ID: EX10 NAME : 10-YR . EXISTING LESS BYPASS
SBUH METHODOLOGY
TOTAL AREA . . . . . . . : 2 .24 Acres BASEFLOWS: 0 .00 CfS
RAINFALL TYPE . . . . : KC24HR PERV IMP
PRECIPITATION . . . . : 2 .95 inches AREA . . : 2 .24 Acres 0 .00 Acr€
TIME INTERVAL . . . . : 10 .00 min CN . . . . . 85 .00 98 .00
TC . . . . : 36 .46 min 36 .46 min
ABSTRACTION COEFF: 0 .20
TcReach - Sheet L : 300 .00 ns:0 .1500 p2yr : 2 .10 s :0 .0122
TcReach - Shallow L : 70 .00 ks: 11 .00 s:0 .0122
PEAK RATE : 0 .53 cfs VOL : 0 .29 Ac-ft TIME : 480 min
BASIN ID : EX100 NAME: 100-YR . EXISTING LESS BYPASS
SBUH METHODOLOGY
TOTAL AREA . . . . . . . : 2 .24 Acres BASEFLOWS: 0 .00 cfs
RAINFALL TYPE . . . . : KC24HR PERV IMP
PRECIPITATION . . . . : 3 .95 inches AREA . . : 2 .24 Acres 0 .00 Acr€
TIME INTERVAL . . . . : 10 .00 min CN . . . . : 85 .00 98 .00
TC . . . . : 36 .46 min 36 .46 min
ABSTRACTION COEFF : 0 .20
TcReach - Sheet L : 300 .00 ns:0 .1500 p2yr : 2 . 10 s:0 .0122
TcReach - Shallow L: 70 .00 ks: 11 .00 s:0 .0122
PEAK RATE : 0 .89 cfs VOL : 0 .45 Ac-ft TIME: 480 min
10/27/98 11 :43: 14 am Pacific Engineering Design Inc page
BRIERS PLAT - JOB NO .98016
DRAINAGE CALCULATIONS
HYDROGRAPH SUMMARY
PEAK TIME VOLUME
HYD RUNOFF OF OF Contrib
NUM RATE PEAK HYDRO Area
cfs min . cf\AcFt Acres
1 0 .263 490 7067 cf 2 .24 �
2 0 .531 480 12573 cf 2 .241A-0 7 EX �4lP s
�n��(t.�.1�
4 0 .829 470 11235 cf 2 .24
3 0 .888 480 19622 cf 2 .24. � -
_ Z �
5 1 .318 470 17470 cf 2 .24Lvo 19-DC-U c�_
6 1 .917 470 25088 cf 2 .2 4. tCO Q DEV 54AASS
7 0 .251 540 11235 cf 2 .24
o z�t ¢oc�l Fn
8 0 .517 510 17470 cf 2 .24 ( +� {
9 0 .874 500 25088 cf 2 .24
11 0 .008 480 120 cf 0 .04__-_ZAP FK $� PDrSS
12 0 .015 470 ( 1 L(PhSS
213 cf O .04 2. (�. E.X..
13 0 .025 470 333 cf 0 .04_1()ci ,_ E34�PN5S
14 0 .020 470 258 cf 0 .04 Zt�Q MV, Fj PASS
15 0 .029 470 375 cf 0 .04l(� 'QFv_,aL1-ph55
16 0 .039 470 512 cf 0 .04 104 Dr-- 6�PAsS
10/27/98 .11 : 43 : 14 am Pacific Engineering Design Inc page
BRIERS PLAT -- JOB NO .98O16
DRAINAGE CALCULATIONS
STAGE STORAGE TABLE
RECTANGULAR VAULT ID No . 1
Description: UNDERGROUND VAULT
Length : 52 .00 ft . Width: 20 .00 ft . voids: 1 .000
STAGE (----STORAGE----) STAGE (----STORAGE----) STAGE (----STORAGE----) STAGE (----STORAGE---->
(ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft-
100.00 0.0000 0.0000 101.30 1352 0.0310 102.60 2704 0.0621 103.90 4056 0.0931
100.10 104.00 0.0024 101.40 1456 0.0334 102.70 2808 0.0645 104.00 4160 0.0955
100.20 208.00 0.0048 101.50 1560 0.0358 102.80 2912 0.0669 104.10 4264 0.0979
100.30 312.00 0.0072 101.60 1664 0.0382 102.90 3016 0.0692 104.20 4368 0.1003
100.40 416.00 0.0096 101.70 1768 0.0406 103.00 3120 0.0716 104.30 4472 0.1027
100.50 520.00 0.0119 101.80 1872 0.0430 103.10 3224 0.0740 104.40 4576 0.1051
100.60 624.00 0.0143 101.90 1976 0.0454 103.20 3328 0.0764 104.50 4680 0.1074
100.70 728.00 0.0167 102.00 2080 0.0478 103.30 3432 0.0788 104.60 4784 0.1098
100.80 832.00 0.0191 102.10 2184 0.0501 103.40 3536 0.0812 104.70 4888 0.1122
100.90 936.00 0.0215 102.20 2288 0.0525 103.50 3640 0.0836 104.80 4992 0.1146
101.00 1040 0.0239 102.30 2392 0.0549 103.60 3744 0.0860 104.90 5096 0.1170
101.10 1144 0.0263 102.40 2496 0.0573 103.70 3848 0.0883 105.00 5200 0.1194
101.20 1248 0.0287 102.50 2600 0.0597 103.80 3952 0.0907 105.00 5200 0.1194
10/27/98 11 :43 : 14 am Pacific Engineering Design Inc page
BRIERS PLAT JOB NO .98016
DRAINAGE CALCULATIONS
STAGE DISCHARGE TABLE
MULTIPLE ORIFICE ID No . 1
Description: ORIFICE DISCHARGE ASSEMBLY
Outlet Elev: 100 .00
Elev : 98 .00 ft Orifice Diameter : 2 .6602 in .
Elev: 101 .80 ft Orifice 2 Diameter : 2 .7305 in .
Elev: 102 .90 ft Orifice 3 Diameter : 2 .6133 in .
STAGE (--DISCHARGE---) STAGE (--DISCHARGE---) STAGE (--DISCHARGE---) STAGE (--DISCHARGE--->
(f0 ---cfs-- ------- (f0 ---cfs-- ------- (f0 ---cfs-- ------- (f0 ---cfs-- -------
100.00 0.0000 101.30 0.2190 102.60 0.4906 103.90 0.8577
100.10 0.0607 101.40 0.2272 102.70 0.5075 104.00 0.8785
100.20 0.0859 101.50 0.2352 102.80 0.5237 104.10� 0.8987
100.30 0.1052 101.60 0.2429 _102.90 0.5392 104.20 0.9183
100.40 0.1215 101.70 0.2504 103.00 0.6128 104.30 0.9374
100.50 0.1358 101.80 0.2576 103.10 0.6517 104.40 0.9560
100.60 0.1487 101.90 0.3287 103.20 0.6844 104.50 0.9742
100.70 0.1607 102.00 0.3621 103.30 0.7138 104.60 0.9920
100.80 0.1718 102.10 0.3891 103.40 0.7411 104.70 1.0095
100.90 0.1822 102.20 0.4128 103.50 0.7666 104.80 1.0266
101.00 0.1920 102.30 0.4343 103.60 0.7909 104.90 1.0434
101.10 0.2014 102.40 0.4542 103.70 0.8140 105.00 1.0599
101.20 0.2104 102.50 0.4729 103.80 0.8363
10/27/98 11 :44 = 4 am Pacific Engineering Design Inc Page
BRIERS PLAT - JOB NO .98O16
DRAINAGE CALCULATIONS
LEVEL POOL TABLE SUMMARY
MATCH INFLOW -STO- -DIS- (-PEAK-) OUTFLOW STORAGE
(--------DESCRIPTION---------> (cfs) (cfs) --id- --id- (-STAGE) id (cfs) VOL (cf)
-------------------------------------------------------------------------------------
-------------------------------------------------------------------------------------
2-YR. ........................ 0.25 0.83, 1 1 101.71 7 0.25 1774.83 cf
10-YR. ....................... 0.52 : 1.32 1 1 102.76 8 0.52 2866.64 cf
100.YR. ...................... 0.81 . 1.92 1 1 103.98 9 0.87 4136.22 cf
MAN-MADE CHANNELS
VARIABLES LIST:
Y - FLOW DEPTH B - CHANNEL BOTTOM WIDTH S - CHANNEL SLOPE
0 - FLOWRATE M - CHANNEL SIDE SLOPE N - CHANNEL ROUGHNESS
VARIABLE TO BE SOLVED (Y,D,B,M,S OR N) ? B
Y (FT) ? .333 RESULTS
0 (CFS) ? 0.25
M (FT/FT) ? 3 B= 2.20 FT "
S (FT/FT) ? .02 A= 1.06 SF
N (FT"1/6) ? 0.35 P= 4.30 FT
V= 0.23 FPS
F= 0.08 SUB-CRITICAL FLOW
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MAN-MADE CHANNELS
VARIABLES LIST:
Y - FLOW DEPTH B - CHANNEL BOTTOM WIDTH S - CHANNEL SLOPE
0 - FLOWRATE M - CHANNEL SIDE SLOPE N - CHANNEL ROUGHNESS
VARIABLE TO BE SOLVED (Y,O,B,M,S OR N) ? Y
0 (CFS) ? .25 RESULTS
B (FT) ? 2.50
M (FT/FT) ? 3 Y= 0.31 FT
S (FT/FT) ? .02 A= 1.08 SF
N (FT"1/6) ? 0.35 P 4.48 FT
V= 0.23 FPS
F= 0.08 SU8-CRITICAL FLOW
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MAN-MADE CHANNELS
VARIABLES LIST:
Y - FLOW DEPTH B - CHANNEL BOTTOM WIDTH S - CHANNEL SLOPE
Q - FLOWRATE M - CHANNEL SIDE SLOPE N - CHANNEL ROUGHNESS
VARIABLE TO BE SOLVED (Y,Q,B,M,S OR N) ? Y
Q (CFS) ? .874 Q( l(�Ot�►2� RESULTS
B (FT) ? 2.50
M (FT/FT) ? 3 Y= 0.24 FT
S (FT/FT) ? .005 A= 0.76 SF
N (FT A1/6) ? .030 P= 4.00 FT
V= 1.15 FPS
F= 0.46 SUB-CRITICAL FLOW
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III. LEVEL II OFF-SITE ANALYSIS
KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL
Collect qualitative data on features such as land use, impervious surfaces, topography, and soil
types.
Collect information on pipe sizes, channel characteristics, drainage structures,
wetland/stream/steep slope (Sensitive) areas.
Verify tributary basins delineated in Task 1 .
Contact neighboring property owners or residents in the area about past or existing drainage
problems and describe in the report (Optional).
Note the date and weather conditions at the time of inspection.
Level 2 or 3 Inspection:
Perform a Level 1 Inspection.
Document existing site conditions (approved drainage systems or pre-1 979 aerial photographs) as
defined in Core Requirement # 3.
Collect quantitative field data (For Level 2, Collect non-survey field data using hand tapes, hand
reel, and rods, and for Level 3 collect field survey profile and cross-section topographic data
prepared by an experienced surveyor.)
Task 4: Drainage System Description and Problem Screening "
Each drainage system component and problem shall be addressed in the Off-Site Analysis Report:
on a map (Task 1), in the narrative, and in the Drainage System Table (See Reference 10B).
Drainage system components:
The following information about drainage system components such as pipes, culverts, bridges,
outfalls, ponds, tanks, and vaults shall be included in the report:
Location (corresponding map label and distance downstream/upstream from site discharge)
Physical description (type, size, length, slope, vegetation, and cover)
Problems
Field observations
Existing/potential problems:
All existing/potential problems (ponding water, high/low flows, siltation, erosion, etc.) identified in
the resource review or field inspection shall be described in the report as follows regardless of
whether the proposed project may or may not aggravate the problem. Then, problems that are not
of concern will be screened from further analysis.
Type of problem: magnitude, frequency, and/or duration
Description of problem: ponding water, high or low flows, siltation, erosion, slides
Magnitude of or damage caused by problem: siltation of ponds, dried up ornamental ponds, road
inundation, flooded property, flooded building, flooded septic system, significant destruction of
aquatic habitat or organisms.
General frequency and duration of problem (Dates and time problem occurred, if available)
Design storm or flow (cfs) of the water when problem occurs (Optional for Level 1 and required for
Levels 2 and 3)
Water surface elevation when problem occurs (for example, elevation of building foundation, crest
of roadway, elevation of septic drain fields, or wetland/stream high water mark)
Names and concerns of involved parties (Optional for all levels of analysis)
Current mitigation of problem
Possible cause of problem
Why the proposed project will or will not aggravate (increase the magnitude, frequency, or
duration) the existing problem nor create a new drainage problem. For example, the problem will
not be aggravated if:
0 it is an upgradient drainage problem that will not effect or be affected by project drainage
systems; or
(2) it is a flooding problem and the project will not increase the elevation, duration, or
frequency of elevated water; or
(3) it is a capacity problem and the project proposes controls (pipes, culverts, channels, etc.)
that will convey runoff as specified in Core Requirement #4: Conveyance System.
G3 1.2.2-3 11/92
KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL
1.2.2 CORE REQUIREMENT #2: OFF-SITE ANALYSIS
A proposed project initial submittal shall include an Off-Site Analysis Report that evaluates drainage
system problems (ponding water, high/low flows, siltation, erosion, etc.) upstream, on-site, and
downstream of the proposed project. The design engineer shall demonstrate that the proposed
project has been designed so that it neither aggravates (increases the magnitude, frequency, or
duration of ) an existing drainage problem nor creates a new drainage problem.
Exemption: Permits and approvals requiring drainage review will be exempt from performing an Off-
Site Analysis when the BALD Division determines that the proposed development contains
sufficient measures to adequately protect the downstream drainage system AND,
1) the proposed new impervious surface to be constructed is 5,000 square feet, or less, OR
2) the drainage area from which surface and storm water runoff is to be collected and
concentrated is 5,000 square feet, or less.
Levels of Off-site Analysis "
The Off-Site Analysis report requirements vary depending on the specific site and downstream
conditions. Each project submittal shall include at least a Level 1 analysis. Upon review of the Level
1 analysis, BALD may require a Level 2 or Level 3 analysis. If conditions warrant, additional, more
detailed analysis may be required.
Level 1 Analysis: The Level 1 analysis is a qualitative survey of each downstream system leaving a
site. This analysis is required for all proposed projects and shall be submitted with the initial permit
application. Depending on the findings of the Level 1 analysis, the Level 2 or 3 analysis may need
to be completed and/or additional information may be required. If further analysis is required, the
applicant may schedule a meeting with BALD Division staff.
Level 2 or 3 Analysis: If problems are identified in the Level 1 analysis, either a Level 2 (rough
quantitative) analysis or a Level 3 (more precise quantitative) analysis shall be performed to further
define and evaluate proposed mitigation for the problem. The BALD Division will determine whether
a Level 2 or 3 analysis is required based on the evidence of existing or potential problems identified
in the Level 1 analysis and on the proposed on-site drainage facilities design. The Level 3 analysis
is required when results need to be as accurate as possible: for example, if the site is flat; or if the
system is affected by downstream controls; or if minor changes in the drainage system could flood
roads, buildings, or septic systems; or if the proposed project will contribute more than 15 percent
of the total peak flow to the drainage problem location. The Level 2 or 3 analysis may not be
required, if the BALD Division determines that adequate mitigation can be developed from the Level
1 analysis.
Additional Analysis: Additional, more detailed, hydrologic analysis may be required if the BALD
Division determines that the analysis has not been sufficient to analyze the impacts of a proposed
project on an existing or potential drainage problem. This more detailed analysis will generally
include synthesizing, summing, and phasing hydrographs for the major drainage areas (defined by
major drainage system components affecting routing such as impoundments, restrictions,
confluences, etc.) tributary to the drainage problem areas. The SWM Division will review this
additional analysis.
Specific Requirements for Off-site Analysis• Regardless of the level of Off-Site Analysis required,
the applicant shall: define and map the study area (Task 1), review resources (Task 2), inspect the
study area (Task 3), describe the drainage system and problems (Task 4), and propose mitigation
measures (Task 5) as described below.
3 See Definition Section
��� 1.2.2-1 11/92
The bioswale from the proposed Briere plat runs approximately 140' north of the property line
where it combines with open channel flows from the Summerwind Div. 4 plat detention vault.
This open channel was surveyed by Triad Associates and shows it has a length of approximately
300' at an average slope of 1.4%. At the end of the open channel is a 12" dia. intake pipe which
connects the channel to a large drainage structure (10' long x 3' wide) containing a spillway and
trash screen. An 18" diameter pipe carries flows from the structure to Type II SDMH Basin in
Field Avenue NE and thence into a storm detention pond constructed as part of the Summerwind
development.
A preliminary check of the downstream channel and pipe capacity assuming a worst case which
would be the 100-year storm event with failure occurring at the existing Summerwind detention
vault and the proposed Briere plat vault. The drainage flows are:
• Q = 12.20 cfs from Summer-wind vault based on 21" diameter pipe outfall at 0.51a/o slope
flowing full (detention failure)
• Q = 1.92 cfs from Briere Plat with full development (detention failure)
• Q = 3.09 cfs from 7.53± acre drainage basin north of proposal assuming existing conditions
The total flow at the downstream spillway structure is estimated as 12.20 + 1.92 +3.09 = 17.21±
cfs. Using King County Figure 4.3.5c an 18" diameter culvert would require a Hw/D = 3.2' for a
Type 1 entrance or a Hw= 3.2 x 1.5 = 4.8'. From the Basin Map we estimate the road Field
Avenue NE is at least 4.8' above the culvert invert. It is possible that Field Avenue NE could
overtop in this area; however, the likelihood of simultaneous full failure of both vaults during the
100-year event is very unlikely. Preliminary calculations checking the open channel capacity
showed the water depth at 17.2 cfs would be about 0.53' and have a channel velocity of 3.4's.
I. Existing Conditions
Total On-Site Area= 2.278 Acres
Area of Road Right-of-Way = 0.494 Acres
Tc
370 LF @ S = 1.216% CN - 85 (Meadow or Pasture)
Bypass = 33 x 50 = 0.038 acres
11. Developed Conditions
Total On-Site Area= 2.278 Ac
Bypass = 0.038 Acres - Impervious P2 = 2.10 in.
P 10 = 2.95 in.
2.278 = 0.038 =2.240 Acres P 100= 3.95 in.
Grass = 1.162 Ac CN = 86
Roadways = 0.456 Ac CN= 98
Homes = 0.622 Ac CN= 98
2.240 Ac
Total Existing 2 yr. - 0.263 + 0.008 = 0.271 cfs
10 yr. - 0.531 + 0.015 = 0.546 cfs
100 yr. - 0.888 + 0.025 = 0.913 cfs
Allowable Release Rates = 2 yr. - 0.271 - 0.020= 0.251 cfs
10 yr. - 0.546 - 0.029= 0.517 cfs
100 yr. - 0.913 - 0.039= 0.874 cfs
PACIFIC ENGINEERING DESIGN INC.
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CIVIL ENGINEERING AND PLANNING CONSULTANTS SHEET NO. OF 7�--
CALCULATED BY ( J Y�%� DATE
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CIVIL ENGINEERING AND PLANNING CONSULTANTS SHEET NO. r�J OF
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12/4/98 10: 4 : 34 am pacific Engineering Design Inc page
BRIERE PLAT - JOB NO .98O16
DRAINAGE CALCULATIONS
STAGE DISCHARGE TABLE
MULTIPLE ORIFICE ID No . 1
Description: DISCHARGE ORIFICE ASSEMBLY
Outlet Elev: 411 .48
Elev: 409 .48 ft Orifice Diameter : 2 .125O in .
Elev: 413 .10 ft Orifice 2 Diameter : 2 .2000 in .
Elev: 414 .40 ft Orifice 3 Diameter : 2 .7900 in .
STAGE (--DISCHARGE---) STAGE (--DISCHARGE---) STAGE (--DISCHARGE---) STAGE (--DISCHARGE--->
(ft) ---cfs-- ------- (ft) ---cfs-- ------- (ft) ---cfs-- ------- (ft) ---cfs-- -------
411.48 0.0000 412.70 0.1354 414.00 0.3191 415.30 0.6347
411.50 0.0173 412.80 0.1408 414.10 0.3297 415.40 0.6530
411.60 0.0424 412.90 0.1460 414.20 0.3399 415.50 0.6707
411.70 0.0575 413.00 0.1511 414.30 0.3497 415.60 0.6878
411.80 0.0693 413.10 0.1560 414.40 0.3592 415.70 0.7044
411.90 0.0794 413.20 0.2022 414.50 0.4352 415.80 0.7205
412.00 0.0884 413.30 0.2241 414.60 0.4718 415.90 0.7361
412.10 0.0965 413.40 0.2417 414.70 0.5017 416.00 0.7514
412.20 0.1040 413.50 0.2572 414.80 0.5281 416.10 0.7663
412.30 0.1110 413.60 0.2713 414.90 0.5522 416.20 0.7809
412.40 0.1175 413.70 0.2843 415.00 0.5746 416.23 0.7852
412.50 0.1238 413.80 0.2965 415.10 0.5956
412.60 0.1297 413.90 0.3081 415.20 0.6156
12/4/98 10.28: 16 am Pacific Engineering Design Inc page
BRIERE PLAT - YOB NO .98016
DRAINAGE CALCULATIONS
BASIN SUMMARY
BASIN ID: SUMMER NAME : 100--YR . DEV . FLOW - SUMMERWIND
SBUH METHODOLOGY
TOTAL AREA . . . . . . . 4 .69 Acres BASEFLOWS: 0 .00 cfs
RAINFALL TYPE . . . . KC24HR DERV IMP
PRECIPITATION . . . . : 3 .95 inches AREA . . : 2 .58 Acres 2 . 11 Acre_
TIME INTERVAL . . . . = 10 .00 min CN . . . . : 86 .00 98 .00
TC . . . . : 10 .00 min 10 .00 min
ABSTRACTION COEFF : 0 .20
PEAK RATE : 3 .59 cfs VOL : 1 .19 Ac-ft TIME: 480 min
D A
12/4/98 10: 19: 41 am Pacific: Engineering Design Inc page
BRIERS PLAT - JOB NO .98016
DRAINAGE CALCULATIONS
BASIN SUMMARY
BASIN ID: DEV100 NAME - 100-YR . DEV LESS BYPASS
SBUH METHODOLOGY
TOTAL AREA . . . . . . . 2 .24 Acres BASEFLOWS: 0 .00 cfs
RAINFALL TYPE . . . . = KC24HR DERV IMP
PRECIPITATION . . . . ; 3 .95 inches AREA . . : 1 . 16 Acres 1 .08 Acr<
TIME INTERVAL . . . . - 10 .00 min CN . . . . , 86 .00 ' 98 .00
TC . . . . . 5 .00 min 5 .00 min
ABSTRACTION COEFF = 0 .20
PEAK RATE 1 .92 cfs VOL : 0 .58 Ac-ft TIME: 470 min
A
12/4/98 10 : 17: 30 am Pacific Engineering Design Inc page
BRIERE PLAT - JOB NO .98016
DRAINAGE CALCULATIONS
BASIN SUMMARY
BASIN ID: OFF-100 NAME : OFF-SITE 100-YR . EX . TO CULV .
SBUH METHODOLOGY
TOTAL AREA . . . . . . . : 7 .53 Acres BASEFLOWS: 0 .00 cfs
RAINFALL TYPE . . . . : KC24HR PERV IMP
PRECIPITATION . . . . : 3 .95 inches AREA . . : 7 . 17 Acres 0 .36 Acr
TIME INTERVAL . . . . : 10 .00 min CN . . . . . 85 .25 98 .00
TC . . . . : 37 .01 min 37 .01 min
ABSTRACTION COEFF: 0 .20
TcReach - Sheet L : 300 .00 ns :0 .1500 p2yr : 2 .10 s:0 .0164
TcReach - Shallow L : 200 .00 ks: 11 .00 s:0 .0180
TcReach - Channel L : 410 .00 kc : 20 .00 s:0 .0113
PEAK RATE : 3 .09 cfs VOL : 1 .57 Ac-ft TIME: 480 min
KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL
FIGURE 4.3.5C HEADWATER DEPTH FOR SMOOTH INTERIOR PIPE CULVERTS WITH INLET CONTROL
180 10,000
168 8,000 EXAMPLE ( 1 ) (2) (3)6. ENTRANCE TYPE
156 6,000 0=42 inches (3.5 feet) _ 6= SQUARE EDGE KITH
5,000 0.120 cfs ----- r4.
-
144 HEADWALL
4,000 6. 5.
132 �0 a feet
120
2,000 (3) 2.2 7.7 -- 4.---- - 1 t
108 3. I '
e0 in feet 3.
96 1,000 3' "s PLAN
GROOVE END WITH
800 _ _ HEADWALL
84 — 600 - 2• -- 2.
500
i
72 400 �
N E i3 t
= 300 �y jQ� = I.5 1
1.5 I
Z / i Cr
60 v � 1.5
200 //Z PLAN
Z 1-1 '
o GROOVE END
54 0 / C j' Q PROJECTING
o
w 48 Uj 100 ^
J / Cr 80
a =
/ = 60 0- 1.0 1.0
U
U 1 i/ W
42 0
o 50 HW S ALE ENTRANCE o I.O
40 D TYPE
w .9
w I
36
It— — .9
W 30 (I) Square edge vritn Q
neod.all 3 .9
a 33 c
Q 20
�3)
Groove end.nth30 head.all S 8 .6
Groove and '8
27 projecting
r— 10
-•7 7-
24 8 .7
6 To use scale (2) or (3) project
2 1 5 horizontally to scale (1),thin
4 use sfroight inclined line through
D and 0 scales,or revert@ at 6
3 illustrated, 6 6
18
i
2
15 5
.5 .5
1.0 — — ---
12
4.3.5-11 1/90
r •
MAN-MADE CHANNELS
VARIABLES LIST:
Y - FLOW DEPTH B - CHANNEL BOTTOM WIDTH S - CHANNEL SLOPE
Q - FLOWRATE M - CHANNEL SIDE SLOPE N - CHANNEL ROUGHNESS
VARIABLE TO BE SOLVED (Y, Q, B,M, S OR N) ? Y
Q (CFS) ? 17 .21 RESULTS
B (FT) ? 8
M (FT/FT) ? 3 Y= 0. 53 FT
h
S (FT/FT) ? . 014 A= 5. 04 SF
N (FT^1/6) ? . 030 P= 11 . 33 FT
V= 3 .42 FPS
F= 0 . 90 SUB-CRITICAL FLOW
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v ►
CULVERTS
RESULTS
DIAMETER (IN) ? 18 HEADWATER (FT) FLOWRATE (CFS)
LENGTH (FT) ? 100
102.50 IC 7.61
FRICTION COEFF (FT A1/6) ? .013 103.00 IC 9.83
ENT+EXIT COEFF ? 0.5 103.50 IC 11.63 3
INLET CONTROL COEFF ? 0.62 104.00 IC 13.19
104.50 IC 14.58
INV ELEV OUT (FT) ? 100.00 105.00 IC 15.85
INV ELEV IN (FT) ? 101.00 105.50 IC 17.03
TAILWATER ELEV (FT) ? 101.00 106.00 IC 18.13
ELEV INCREMENT (FT) ? 0.5 106.50 IC 19.16
107.00 IC 20.15
107.50 IC 21.00
108.00 IC 21.98
108.50 IC 22.84
109.00 IC 23.67
109.50 IC 24.48
110.00 IC 25.25
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CULVERTS
RESULTS
DIAMETER (IN) ? 18 HEADWATER (FT) FLOWRATE (CFS)
LENGTH (FT) ? 100
102. 50 IC 6. 14
FRICTION COEFF (FT"-1/6) ? . 012 102. 70 IC 6. 91
ENT+EXIT COEFF ? IS 102. 90 IC 7. 60
INLET CONTROL COEFF ? . 5 103. 10 IC 8 . 24
103. 30 IC 8 . 83
!NV ELE11 OUT (FT) ? 100 103. 50 IC 9. 38
INV ELEV IN (FT) ? 1.01. 1.03. 70 IC 9. 90
TAILWATER ELEV (FT) ? 101 103. 90 IC: 10. 40
ELEV INC;REI'4ENT (FT) ? . 2 104 . 10 IC 10. 87
104 . 30 IC 11. 32
104 . 50 IC 11. 76
104 . 70 I , 1.2. 1.8 M??1
104 . 90 IC: 12. 58
105. 10 IC 12. 98
105. 30 IC 13. 36
105. 50 IC 13. 73
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