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dtc u:\192500227\transportation\preliminary\hydraulics\hydraulic design and floodplain eval report\453107_rte 531 floodplain evaluation_memo_20130709.docx
To: Regional Hydraulics Engineer From: Robert Cody/Daniel Clark NYSDOT Region 4 Stantec File: 531_Floodplain Evaluation
Memo_20130709 Date: July 9, 2013
Reference: Route 531 Terminus Improvement Project, Technical Memorandum Floodplain Evaluation
INTRODUCTION As part of the Route 531 Terminus Improvement Project, an existing 10’x20’ culvert that carries Salmon Creek under NY Route 31 in the Town of Ogden/Sweden will either be extended or replaced depending on the selected alternative.
This report has been prepared to ensure project compliance with Executive Order 11988 (Floodplain Management), as contained in 23CFR650 Subpart A (Location and Hydraulic Design of Encroachments on Floodplains), as well as 6NYCRR 502 (Floodplain Management Criteria for State Projects).
Included in subsequent sections of this document is an assessment of the existing hydrologic and hydraulic conditions of the culvert, stream and adjoining regulatory floodplain, as well as the improved (extended or replaced) culvert and an evaluation of potential impacts to the floodplain.
Consideration was also given to the current Monroe County Flood Insurance Study (FIS), dated August 28, 2008, which includes Salmon Creek.
EXISTING CONDITIONS
The existing Salmon Creek culvert that conveys stream flow under Route 31 is a 10’x20’ reinforced concrete culvert that was constructed in 1915 using conventional bridge components and construction techniques (i.e. abutments, wing walls and footings). The culvert is a 3-sided structure and as such has a natural channel bottom running its full length and solid concrete walls on either side. Although there are no signs of the culvert having inadequate hydraulic capacity, due to its age, portions of the culvert are severely deteriorated.
July 9, 2013 Page 2 of 27
Reference: Route 531 Terminus Improvement Project, Technical Memorandum Floodplain Evaluation
dtc u:\192500227\transportation\preliminary\hydraulics\hydraulic design and floodplain eval report\453107_rte 531 floodplain evaluation_memo_20130709.docx
Photo 1: Existing Culvert looking downstream
Salmon Creek, which crosses under Route 31 approximately 2,800 ft. west of Route 36, is a 30 mile long northeasterly flowing non-protected Class C stream. It originates to the south in the swamplands of the Town of Clarendon, Orleans County and discharges to Braddock Bay/Lake Ontario approximately 13.4 miles to the north. Although the creek’s overall contributing watershed at Lake Ontario is about 900 square miles, the subject section of the stream at the project site is well upstream, with a contributing drainage area of only 14.3 square miles.
Approximately 75 ft south of Route 31, but outside the limits of any proposed project-related grading, a minor tributary to Salmon Creek, Spring Creek (also a Class C stream), discharges into Salmon Creek. The approximate contributing watershed to Spring Creek is 3.1 square miles.
The upstream reach of Salmon Creek meanders through Northampton Park before entering the subject culvert. The channel bottom is comprised of random-sized cobbles, fine silts and glacial till material, and both channel banks are generally lined with moderately dense scrub brush and randomly spaced trees.
Based on the aforementioned Monroe County FIS, there is a regulatory 100-year floodplain upstream of the project area that is a relatively narrow band, centered on both Salmon Creek
July 9, 2013 Page 3 of 27
Reference: Route 531 Terminus Improvement Project, Technical Memorandum Floodplain Evaluation
dtc u:\192500227\transportation\preliminary\hydraulics\hydraulic design and floodplain eval report\453107_rte 531 floodplain evaluation_memo_20130709.docx
and Spring Creek. Base (100-year) Flood elevations however are not determined for this specific reach of Salmon Creek.
Downstream of Route 31, Salmon Creek continues to flow in a northeasterly direction through residential properties and farmland, but with slightly wider floodplain boundaries on either side of the channel. Base flood elevations also do not exist immediately downstream of Route 31 either. See Figure 1 for the project location.
Figure 1: Project Location
MONROE COUNTY FEMA FLOOD INSURANCE STUDY
As stated, Salmon Creek is included in the countywide FIS, and a 100-year flood boundary has been adopted adjacent to Salmon Creek within the proximity of the project. Figure 2 illustrates the boundaries of the regulatory floodplain in the vicinity of the project.
Salmon Creek Culvert Location
Project Begins (Route 31)
Project Ends (Route 531)
July 9, 2013 Page 4 of 27
Reference: Route 531 Terminus Improvement Project, Technical Memorandum Floodplain Evaluation
dtc u:\192500227\transportation\preliminary\hydraulics\hydraulic design and floodplain eval report\453107_rte 531 floodplain evaluation_memo_20130709.docx
Figure 2: Flood Plain Boundaries at Route 531 and Salmon Creek
Salmon Creek Culvert Location
July 9, 2013 Page 5 of 27
Reference: Route 531 Terminus Improvement Project, Technical Memorandum Floodplain Evaluation
dtc u:\192500227\transportation\preliminary\hydraulics\hydraulic design and floodplain eval report\453107_rte 531 floodplain evaluation_memo_20130709.docx
Figure 2: (Cont.)
The limits of a detailed hydrologic and hydraulic analysis used to establish the (100-year) Base Flood elevations and regulatory floodway however begin approximately 10 miles downstream, or north of the project site. As such, detailed FEMA-developed hydrologic analyses and hydraulic modeling do not exist for use as the basis for assessing pre- vs post-construction impacts on flood levels. Therefore, existing hydrology and hydraulic calculations that are needed to establish a baseline for assessing future potential impacts were prepared as part of this report.
HYDROLOGY
Since documented FIS flowrates for the subject reach of Salmon Creek do not exist within the countywide FIS, the 50-year design flow and 100-year check flow were computed using the USGS “StreamStats” web-based geographic information system (GIS). USGS “StreamStats” methodology easily delineates watershed boundaries for a given location and estimates
July 9, 2013 Page 6 of 27
Reference: Route 531 Terminus Improvement Project, Technical Memorandum Floodplain Evaluation
dtc u:\192500227\transportation\preliminary\hydraulics\hydraulic design and floodplain eval report\453107_rte 531 floodplain evaluation_memo_20130709.docx
discharge flowrates using standard regression equations for this geographic location. This methodology is also consistent with the “Magnitude and Frequency of Floods in New York (USGS Scientific Investigations Report 2006-5112).
Figure 3 illustrates the contributing watershed boundaries.
Figure 3: Watershed Boundaries
The following table summarizes the estimated flowrates for the design (50-year) and check (100-year) flowrates within Salmon Creek.
Table 1: Watershed Summary
Watershed Name
Contributing Watershed
(mi2)
Design Q50
(cfs)
Base Flood Q100
(cfs)Salmon Creek at Rte. 531 14.3 695 781
Existing 10’ x 20’ Reinforced Concrete Culvert on Salmon Creek
July 9, 2013 Page 7 of 27
Reference: Route 531 Terminus Improvement Project, Technical Memorandum Floodplain Evaluation
dtc u:\192500227\transportation\preliminary\hydraulics\hydraulic design and floodplain eval report\453107_rte 531 floodplain evaluation_memo_20130709.docx
HYDRAULIC ANALYSIS
Using USACE HEC RAS software, the existing stream and culvert were modeled in order to evaluate and estimate approximate existing flood levels for both the 50-year and 100-year storm events. As part of the process of creating the model, detailed hydraulic cross-section of the culvert and upstream and downstream reaches of the stream were obtained via instrument survey on June 13, 2011.
Channel bottom and overbank roughness factors were obtained from visual observation and those roughness factors used are summarized in the following table.
Table 2: Manning’s “n” Values
Type of Cover Manning's "n" ValueConcrete 0.013River Bed- Rocks 0.04Heavy Stone Fill 0.05Grass and Brush 0.3-0.6Trees and Brush 0.1
The three (3) alternatives for the project include varying degrees of culvert modifications. Both alternative 2 and 3 includes lengthening the existing culvert by 15 ft. Alternative 5 however, includes the full replacement of the culvert with a similar sized structure.
Given the existing and proposed culvert geometry, the following table summarizes the estimated water surface elevations and stream flow velocities and provides a comparison of the impacts of each culvert alternative on existing flood levels and velocities. In addition, considering the low chord elevation of the existing (and proposed) culvert is 530.21 ft., the table also illustrates that under all scenarios, there will be sufficient freeboard of at least 2 ft.
July 9, 2013 Page 8 of 27
Reference: Route 531 Terminus Improvement Project, Technical Memorandum Floodplain Evaluation
dtc u:\192500227\transportation\preliminary\hydraulics\hydraulic design and floodplain eval report\453107_rte 531 floodplain evaluation_memo_20130709.docx
Table 3: Flood Elevations and Velocities for Alternatives 2 and 3
July 9, 2013 Page 9 of 27
Reference: Route 531 Terminus Improvement Project, Technical Memorandum Floodplain Evaluation
dtc u:\192500227\transportation\preliminary\hydraulics\hydraulic design and floodplain eval report\453107_rte 531 floodplain evaluation_memo_20130709.docx
Table 4: Flood Elevations and Velocities for Alternative 5
The existing HEC-RAS and proposed HEC-RAS input and output data is attached.
July 9, 2013 Page 10 of 27
Reference: Route 531 Terminus Improvement Project, Technical Memorandum Floodplain Evaluation
dtc u:\192500227\transportation\preliminary\hydraulics\hydraulic design and floodplain eval report\453107_rte 531 floodplain evaluation_memo_20130709.docx
IMPACTS ON FLOODPLAIN VALUES
As explained and illustrated above, there will be a negligible impact on flood levels and stream flow velocities at the project site. As such, flood boundaries will remain unchanged by this project. This project proposes no additional fill material to be placed within the floodplain for both Alternative 2 and 3. Alternative 5 will however require the placement of a minor amount of fill to accommodate the roadway embankment. But considering the minor quantity, the effect on floodplain storage will be negligible.
CONCLUSION
The existing culvert under Route 31 currently has excess hydraulic capacity and there are no visual signs of performance issues. Each of the alternatives under consideration will essentially match the existing hydraulic opening and as such will result in negligible effects (if any) on flood levels or stream flow velocities.
In accordance with 6 NYCRR 502 – Floodplain Management for State projects, it is concluded that (1) a significant encroachment does not exist, (2) there is no significant potential for interruption or termination of a transportation facility which is needed for emergency vehicles and (3) there are no significant impacts on natural beneficial floodplain values.
Attachment: Existing HEC-RAS Input/output data Propose HEC-RAS Input/output data
July 9, 2013 Page 11 of 27
Reference: Route 531 Terminus Improvement Project, Technical Memorandum Floodplain Evaluation
dtc u:\192500227\transportation\preliminary\hydraulics\hydraulic design and floodplain eval report\453107_rte 531 floodplain evaluation_memo_20130709.docx
Existing Hec-Ras Input/Output Data
0 100 200 300 400526
527
528
529
530
531
532
533
RTE 531at Salmon Creek Plan: Existing Survey 7/5/2013
Geom: Existing Model Survey RS = 14
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04
.1 .04
.1
0 50 100 150 200 250 300 350525
526
527
528
529
530
531
RTE 531at Salmon Creek Plan: Existing Survey 7/5/2013
Geom: Existing Model Survey RS = 13
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Levee
Bank Sta
.1 .04
.1
.04 .1 .04
.1
0 20 40 60 80 100 120 140 160525.5
526.0
526.5
527.0
527.5
528.0
528.5
529.0
529.5
RTE 531at Salmon Creek Plan: Existing Survey 7/5/2013
Geom: Existing Model Survey RS = 12
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04 .1
0 100 200 300 400 500524
526
528
530
532
534
536
538
540
542
RTE 531at Salmon Creek Plan: Existing Survey 7/5/2013
Geom: Existing Model Survey RS = 11
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Levee
Bank Sta
.1 .04
.1
0 50 100 150 200 250 300 350 400522
524
526
528
530
532
534
536
538
540
RTE 531at Salmon Creek Plan: Existing Survey 7/5/2013
Geom: Existing Model Survey RS = 10
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Levee
Bank Sta
.1 .04 .1
0 20 40 60 80 100 120 140 160522
524
526
528
530
532
534
RTE 531at Salmon Creek Plan: Existing Survey 7/5/2013
Geom: Existing Model Survey RS = 9
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04 .1
0 50 100 150 200 250522
524
526
528
530
532
534
536
538
RTE 531at Salmon Creek Plan: Existing Survey 7/5/2013
Geom: Existing Model Survey RS = 8
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04 .1
0 50 100 150 200518
520
522
524
526
528
530
532
534
RTE 531at Salmon Creek Plan: Existing Survey 7/5/2013
Geom: Existing Model Survey RS = 7
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.06 .04 .06
0 50 100 150 200518
520
522
524
526
528
530
532
534
RTE 531at Salmon Creek Plan: Existing Survey 7/5/2013
Geom: Existing Model Survey RS = 6.9 Culv Salmon Creek Culvert at 531
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.06 .04 .06
0 50 100 150 200520
522
524
526
528
530
532
534
RTE 531at Salmon Creek Plan: Existing Survey 7/5/2013
Geom: Existing Model Survey RS = 6.9 Culv Salmon Creek Culvert at 531
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.06 .04 .06
0 50 100 150 200520
522
524
526
528
530
532
534
RTE 531at Salmon Creek Plan: Existing Survey 7/5/2013
Geom: Existing Model Survey RS = 6
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.06 .04 .06
0 50 100 150 200 250518
520
522
524
526
528
530
532
534
RTE 531at Salmon Creek Plan: Existing Survey 7/5/2013
Geom: Existing Model Survey RS = 5
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Ineff
Bank Sta
.06 .04
.06
0 50 100 150 200 250520
522
524
526
528
530
532
534
536
RTE 531at Salmon Creek Plan: Existing Survey 7/5/2013
Geom: Existing Model Survey RS = 4
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04 .1
0 50 100 150 200 250518
520
522
524
526
528
530
532
534
536
538
RTE 531at Salmon Creek Plan: Existing Survey 7/5/2013
Geom: Existing Model Survey RS = 3
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04 .1
0 50 100 150 200 250520
522
524
526
528
530
532
534
536
538
RTE 531at Salmon Creek Plan: Existing Survey 7/5/2013
Geom: Existing Model Survey RS = 2
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04 .1
0 50 100 150 200 250 300520
522
524
526
528
530
532
RTE 531at Salmon Creek Plan: Existing Survey 7/5/2013
Geom: Existing Model Survey RS = 1
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04 .1
HEC-RAS Plan: Existing Surv River: SALMON CREEK Reach: MAINReach River Sta Profile Q Total Min Ch El W.S. Elev Crit W.S. E.G. Elev E.G. Slope Vel Chnl Flow Area Top Width Froude # Chl
(cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) MAIN 14 50 Yr 695.00 526.74 529.82 529.62 530.17 0.008664 6.07 223.32 282.65 0.70MAIN 14 100 Yr 781.00 526.74 530.00 530.31 0.007360 5.88 278.14 307.50 0.65
MAIN 13 50 Yr 695.00 525.90 529.44 528.61 529.60 0.003152 3.46 265.53 205.11 0.42MAIN 13 100 Yr 781.00 525.90 529.66 528.71 529.80 0.002886 3.45 315.35 245.75 0.39
MAIN 12 50 Yr 695.00 525.57 529.07 529.38 0.003715 4.72 215.33 144.35 0.48MAIN 12 100 Yr 781.00 525.57 529.28 529.60 0.003540 4.82 247.53 152.32 0.47
MAIN 11 50 Yr 695.00 525.39 528.94 528.04 529.18 0.005452 4.18 245.70 197.75 0.45MAIN 11 100 Yr 781.00 525.39 529.19 528.19 529.41 0.004774 4.14 296.20 217.20 0.43
MAIN 10 50 Yr 695.00 522.82 527.56 526.61 528.18 0.008544 6.34 109.57 41.99 0.69MAIN 10 100 Yr 781.00 522.82 527.86 526.84 528.49 0.008385 6.34 123.42 51.16 0.69
MAIN 9 50 Yr 695.00 523.42 527.45 527.79 0.003587 4.70 154.88 55.59 0.47MAIN 9 100 Yr 781.00 523.42 527.77 528.12 0.003257 4.78 172.77 57.20 0.46
MAIN 8 50 Yr 695.00 522.59 527.08 527.58 0.005508 5.72 130.45 49.08 0.58MAIN 8 100 Yr 781.00 522.59 527.43 527.93 0.004805 5.74 147.79 50.61 0.55
MAIN 7 50 Yr 695.00 519.30 526.25 524.22 526.91 0.005737 6.51 106.83 20.01 0.50MAIN 7 100 Yr 781.00 519.30 526.51 524.50 527.27 0.006329 6.97 112.00 20.04 0.52
MAIN 6.9 Culvert
MAIN 6 50 Yr 695.00 520.57 525.59 526.49 0.008989 7.62 91.21 20.15 0.63MAIN 6 100 Yr 781.00 520.57 525.69 526.78 0.010616 8.37 93.33 20.16 0.69
MAIN 5 50 Yr 695.00 519.99 525.46 524.27 525.87 0.003563 5.79 210.28 162.99 0.48MAIN 5 100 Yr 781.00 519.99 525.63 524.57 526.04 0.003523 5.91 239.88 169.47 0.48
MAIN 4 50 Yr 695.00 520.34 524.92 524.04 525.35 0.005386 5.58 200.49 179.06 0.57MAIN 4 100 Yr 781.00 520.34 525.08 524.50 525.53 0.005319 5.75 231.18 191.41 0.57
MAIN 3 50 Yr 695.00 519.99 524.63 524.96 0.003313 5.05 249.19 176.95 0.46MAIN 3 100 Yr 781.00 519.99 524.78 525.14 0.003453 5.30 276.46 181.75 0.47
MAIN 2 50 Yr 695.00 520.34 524.13 523.69 524.57 0.005718 5.79 213.89 168.48 0.59MAIN 2 100 Yr 781.00 520.34 524.26 523.93 524.73 0.005906 6.05 236.16 169.51 0.60
MAIN 1 50 Yr 695.00 520.05 522.96 522.96 523.65 0.012398 7.07 151.74 163.80 0.83MAIN 1 100 Yr 781.00 520.05 523.11 523.11 523.81 0.011829 7.22 178.53 182.69 0.82
July 9, 2013 Page 12 of 27
Reference: Route 531 Terminus Improvement Project, Technical Memorandum Floodplain Evaluation
dtc u:\192500227\transportation\preliminary\hydraulics\hydraulic design and floodplain eval report\453107_rte 531 floodplain evaluation_memo_20130709.docx
Proposed Hec-Ras Input/Output Data
0 100 200 300 400526
527
528
529
530
531
532
533
RTE 531at Salmon Creek Plan: Proposed Alt 2 & 3 7/5/2013
Geom: Proposed Model Alt 2 & 3 RS = 14
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04
.1 .04
.1
0 50 100 150 200 250 300 350525
526
527
528
529
530
531
RTE 531at Salmon Creek Plan: Proposed Alt 2 & 3 7/5/2013
Geom: Proposed Model Alt 2 & 3 RS = 13
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Levee
Bank Sta
.1 .04
.1
.04 .1 .04
.1
0 20 40 60 80 100 120 140 160525.5
526.0
526.5
527.0
527.5
528.0
528.5
529.0
529.5
RTE 531at Salmon Creek Plan: Proposed Alt 2 & 3 7/5/2013
Geom: Proposed Model Alt 2 & 3 RS = 12
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04 .1
0 100 200 300 400 500524
526
528
530
532
534
536
538
540
542
RTE 531at Salmon Creek Plan: Proposed Alt 2 & 3 7/5/2013
Geom: Proposed Model Alt 2 & 3 RS = 11
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Levee
Bank Sta
.1 .04
.1
0 50 100 150 200 250 300 350 400522
524
526
528
530
532
534
536
538
540
RTE 531at Salmon Creek Plan: Proposed Alt 2 & 3 7/5/2013
Geom: Proposed Model Alt 2 & 3 RS = 10
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Levee
Bank Sta
.1 .04 .1
0 20 40 60 80 100 120 140 160522
524
526
528
530
532
534
RTE 531at Salmon Creek Plan: Proposed Alt 2 & 3 7/5/2013
Geom: Proposed Model Alt 2 & 3 RS = 9
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04 .1
0 50 100 150 200 250522
524
526
528
530
532
534
536
538
RTE 531at Salmon Creek Plan: Proposed Alt 2 & 3 7/5/2013
Geom: Proposed Model Alt 2 & 3 RS = 8
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04 .1
0 50 100 150 200520
522
524
526
528
530
532
534
RTE 531at Salmon Creek Plan: Proposed Alt 2 & 3 7/5/2013
Geom: Proposed Model Alt 2 & 3 RS = 7
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.06 .04 .06
0 50 100 150 200520
522
524
526
528
530
532
534
RTE 531at Salmon Creek Plan: Proposed Alt 2 & 3 7/5/2013
Geom: Proposed Model Alt 2 & 3 RS = 6.9 Culv Salmon Creek Culvert at 531
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.06 .04 .06
0 50 100 150 200520
522
524
526
528
530
532
534
RTE 531at Salmon Creek Plan: Proposed Alt 2 & 3 7/5/2013
Geom: Proposed Model Alt 2 & 3 RS = 6.9 Culv Salmon Creek Culvert at 531
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.06 .04 .06
0 50 100 150 200520
522
524
526
528
530
532
534
RTE 531at Salmon Creek Plan: Proposed Alt 2 & 3 7/5/2013
Geom: Proposed Model Alt 2 & 3 RS = 6
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.06 .04 .06
0 50 100 150 200 250518
520
522
524
526
528
530
532
534
RTE 531at Salmon Creek Plan: Proposed Alt 2 & 3 7/5/2013
Geom: Proposed Model Alt 2 & 3 RS = 5
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Ineff
Bank Sta
.06 .04
.06
0 50 100 150 200 250520
522
524
526
528
530
532
534
536
RTE 531at Salmon Creek Plan: Proposed Alt 2 & 3 7/5/2013
Geom: Proposed Model Alt 2 & 3 RS = 4
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04 .1
0 50 100 150 200 250518
520
522
524
526
528
530
532
534
536
538
RTE 531at Salmon Creek Plan: Proposed Alt 2 & 3 7/5/2013
Geom: Proposed Model Alt 2 & 3 RS = 3
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04 .1
0 50 100 150 200 250520
522
524
526
528
530
532
534
536
538
RTE 531at Salmon Creek Plan: Proposed Alt 2 & 3 7/5/2013
Geom: Proposed Model Alt 2 & 3 RS = 2
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04 .1
0 50 100 150 200 250 300520
522
524
526
528
530
532
RTE 531at Salmon Creek Plan: Proposed Alt 2 & 3 7/5/2013
Geom: Proposed Model Alt 2 & 3 RS = 1
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04 .1
HEC-RAS Plan: Prop Alt 2&3 River: SALMON CREEK Reach: MAINReach River Sta Profile Q Total Min Ch El W.S. Elev Crit W.S. E.G. Elev E.G. Slope Vel Chnl Flow Area Top Width Froude # Chl
(cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) MAIN 14 50 Yr 695.00 526.74 529.82 529.62 530.17 0.008667 6.07 223.28 282.62 0.70MAIN 14 100 Yr 781.00 526.74 530.00 530.31 0.007364 5.88 278.06 307.48 0.65
MAIN 13 50 Yr 695.00 525.90 529.44 528.61 529.60 0.003155 3.46 265.43 205.07 0.42MAIN 13 100 Yr 781.00 525.90 529.65 528.71 529.80 0.002889 3.45 315.22 245.74 0.39
MAIN 12 50 Yr 695.00 525.57 529.06 529.38 0.003719 4.72 215.21 144.31 0.48MAIN 12 100 Yr 781.00 525.57 529.28 529.60 0.003544 4.82 247.38 152.32 0.47
MAIN 11 50 Yr 695.00 525.39 528.94 528.04 529.18 0.005462 4.19 245.48 197.66 0.45MAIN 11 100 Yr 781.00 525.39 529.18 528.19 529.41 0.004782 4.15 295.93 217.10 0.43
MAIN 10 50 Yr 695.00 522.82 527.54 526.61 528.18 0.008626 6.37 109.05 41.79 0.70MAIN 10 100 Yr 781.00 522.82 527.85 526.84 528.48 0.008475 6.37 122.80 50.57 0.69
MAIN 9 50 Yr 695.00 523.42 527.44 527.78 0.003645 4.72 154.07 55.52 0.47MAIN 9 100 Yr 781.00 523.42 527.76 528.11 0.003301 4.80 171.99 57.13 0.46
MAIN 8 50 Yr 695.00 522.59 527.06 527.56 0.005663 5.77 129.24 48.97 0.59MAIN 8 100 Yr 781.00 522.59 527.41 527.92 0.004907 5.78 146.74 50.52 0.56
MAIN 7 50 Yr 695.00 520.01 526.25 524.38 526.95 0.006108 6.70 103.67 20.00 0.52MAIN 7 100 Yr 781.00 520.01 526.51 524.67 527.31 0.006714 7.18 108.82 20.03 0.54
MAIN 6.9 Culvert
MAIN 6 50 Yr 695.00 520.57 525.59 526.49 0.008989 7.62 91.21 20.15 0.63MAIN 6 100 Yr 781.00 520.57 525.69 526.78 0.010616 8.37 93.33 20.16 0.69
MAIN 5 50 Yr 695.00 519.99 525.46 524.27 525.87 0.003563 5.79 210.28 162.99 0.48MAIN 5 100 Yr 781.00 519.99 525.63 524.57 526.04 0.003523 5.91 239.88 169.47 0.48
MAIN 4 50 Yr 695.00 520.34 524.92 524.04 525.35 0.005386 5.58 200.49 179.06 0.57MAIN 4 100 Yr 781.00 520.34 525.08 524.50 525.53 0.005319 5.75 231.18 191.41 0.57
MAIN 3 50 Yr 695.00 519.99 524.63 524.96 0.003313 5.05 249.19 176.95 0.46MAIN 3 100 Yr 781.00 519.99 524.78 525.14 0.003453 5.30 276.47 181.75 0.47
MAIN 2 50 Yr 695.00 520.34 524.13 523.69 524.57 0.005718 5.79 213.89 168.48 0.59MAIN 2 100 Yr 781.00 520.34 524.26 523.93 524.73 0.005906 6.05 236.17 169.51 0.60
MAIN 1 50 Yr 695.00 520.05 522.96 522.96 523.65 0.012398 7.07 151.74 163.80 0.83MAIN 1 100 Yr 781.00 520.05 523.11 523.11 523.81 0.011829 7.22 178.53 182.69 0.82
0 100 200 300 400526
527
528
529
530
531
532
533
RTE 531at Salmon Creek Plan: Proposed Alt 5 7/9/2013
Geom: Proposed Model Alt 5 RS = 14
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04
.1 .04
.1
0 50 100 150 200 250 300 350525
526
527
528
529
530
531
RTE 531at Salmon Creek Plan: Proposed Alt 5 7/9/2013
Geom: Proposed Model Alt 5 RS = 13
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Levee
Bank Sta
.1 .04
.1
.04 .1 .04
.1
0 20 40 60 80 100 120 140 160525.5
526.0
526.5
527.0
527.5
528.0
528.5
529.0
529.5
RTE 531at Salmon Creek Plan: Proposed Alt 5 7/9/2013
Geom: Proposed Model Alt 5 RS = 12
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04 .1
0 100 200 300 400 500524
526
528
530
532
534
536
538
540
542
RTE 531at Salmon Creek Plan: Proposed Alt 5 7/9/2013
Geom: Proposed Model Alt 5 RS = 11
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Levee
Bank Sta
.1 .04
.1
0 50 100 150 200 250 300 350 400522
524
526
528
530
532
534
536
538
540
RTE 531at Salmon Creek Plan: Proposed Alt 5 7/9/2013
Geom: Proposed Model Alt 5 RS = 10
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Levee
Bank Sta
.1 .04 .1
0 20 40 60 80 100 120 140 160522
524
526
528
530
532
534
RTE 531at Salmon Creek Plan: Proposed Alt 5 7/9/2013
Geom: Proposed Model Alt 5 RS = 9
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04 .1
0 50 100 150 200 250522
524
526
528
530
532
534
536
538
RTE 531at Salmon Creek Plan: Proposed Alt 5 7/9/2013
Geom: Proposed Model Alt 5 RS = 8
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04 .1
0 50 100 150 200520
522
524
526
528
530
532
534
RTE 531at Salmon Creek Plan: Proposed Alt 5 7/9/2013
Geom: Proposed Model Alt 5 RS = 7
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.06 .04 .06
0 50 100 150 200520
522
524
526
528
530
532
534
RTE 531at Salmon Creek Plan: Proposed Alt 5 7/9/2013
Geom: Proposed Model Alt 5 RS = 6.9 Culv Salmon Creek Culvert at 531
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.06 .04 .06
0 50 100 150 200520
522
524
526
528
530
532
534
RTE 531at Salmon Creek Plan: Proposed Alt 5 7/9/2013
Geom: Proposed Model Alt 5 RS = 6.9 Culv Salmon Creek Culvert at 531
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.06 .04 .06
0 50 100 150 200520
522
524
526
528
530
532
534
RTE 531at Salmon Creek Plan: Proposed Alt 5 7/9/2013
Geom: Proposed Model Alt 5 RS = 6
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.06 .04 .06
0 50 100 150 200 250518
520
522
524
526
528
530
532
534
RTE 531at Salmon Creek Plan: Proposed Alt 5 7/9/2013
Geom: Proposed Model Alt 5 RS = 5
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Ineff
Bank Sta
.06 .04
.06
0 50 100 150 200 250520
522
524
526
528
530
532
534
536
RTE 531at Salmon Creek Plan: Proposed Alt 5 7/9/2013
Geom: Proposed Model Alt 5 RS = 4
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04 .1
0 50 100 150 200 250518
520
522
524
526
528
530
532
534
536
538
RTE 531at Salmon Creek Plan: Proposed Alt 5 7/9/2013
Geom: Proposed Model Alt 5 RS = 3
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04 .1
0 50 100 150 200 250520
522
524
526
528
530
532
534
536
538
RTE 531at Salmon Creek Plan: Proposed Alt 5 7/9/2013
Geom: Proposed Model Alt 5 RS = 2
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04 .1
0 50 100 150 200 250 300520
522
524
526
528
530
532
RTE 531at Salmon Creek Plan: Proposed Alt 5 7/9/2013
Geom: Proposed Model Alt 5 RS = 1
Station (ft)
Ele
vatio
n (ft
)
Legend
WS 100 Yr
WS 50 Yr
Ground
Bank Sta
.1 .04 .1
HEC-RAS Plan: Prop Alt 5 River: SALMON CREEK Reach: MAINReach River Sta Profile Q Total Min Ch El W.S. Elev Crit W.S. E.G. Elev E.G. Slope Vel Chnl Flow Area Top Width Froude # Chl
(cfs) (ft) (ft) (ft) (ft) (ft/ft) (ft/s) (sq ft) (ft) MAIN 14 50 Yr 695.00 526.74 529.82 529.62 530.17 0.008688 6.08 222.95 282.29 0.70MAIN 14 100 Yr 781.00 526.74 530.00 530.31 0.007396 5.89 277.45 307.37 0.65
MAIN 13 50 Yr 695.00 525.90 529.44 528.61 529.59 0.003171 3.47 264.78 204.81 0.42MAIN 13 100 Yr 781.00 525.90 529.65 528.71 529.80 0.002910 3.46 314.08 245.63 0.40
MAIN 12 50 Yr 695.00 525.57 529.06 529.37 0.003747 4.73 214.39 144.03 0.48MAIN 12 100 Yr 781.00 525.57 529.27 529.59 0.003582 4.84 246.12 152.32 0.47
MAIN 11 50 Yr 695.00 525.39 528.93 528.04 529.17 0.005527 4.20 243.96 197.05 0.45MAIN 11 100 Yr 781.00 525.39 529.17 528.19 529.40 0.004856 4.17 293.67 216.27 0.43
MAIN 10 50 Yr 695.00 522.82 527.44 526.61 528.12 0.009331 6.63 104.84 40.14 0.72MAIN 10 100 Yr 781.00 522.82 527.70 526.84 528.41 0.009601 6.74 115.95 44.37 0.73
MAIN 9 50 Yr 695.00 523.42 527.31 527.69 0.004199 4.93 147.09 54.88 0.51MAIN 9 100 Yr 781.00 523.42 527.59 527.98 0.003925 5.06 162.39 56.27 0.50
MAIN 8 50 Yr 695.00 522.59 526.81 527.41 0.007603 6.31 117.15 47.86 0.67MAIN 8 100 Yr 781.00 522.59 527.12 527.73 0.006665 6.34 132.33 49.25 0.64
MAIN 7 50 Yr 695.00 520.01 525.71 524.38 526.58 0.008386 7.48 92.87 19.94 0.61MAIN 7 100 Yr 781.00 520.01 525.84 524.67 526.88 0.009781 8.18 95.45 19.96 0.66
MAIN 6.9 Culvert
MAIN 6 50 Yr 695.00 520.57 525.59 526.49 0.008989 7.62 91.21 20.15 0.63MAIN 6 100 Yr 781.00 520.57 525.69 526.78 0.010616 8.37 93.33 20.16 0.69
MAIN 5 50 Yr 695.00 519.99 525.46 524.27 525.87 0.003563 5.79 210.28 162.99 0.48MAIN 5 100 Yr 781.00 519.99 525.63 524.57 526.04 0.003523 5.91 239.88 169.47 0.48
MAIN 4 50 Yr 695.00 520.34 524.92 524.04 525.35 0.005386 5.58 200.49 179.06 0.57MAIN 4 100 Yr 781.00 520.34 525.08 524.50 525.53 0.005319 5.75 231.18 191.41 0.57
MAIN 3 50 Yr 695.00 519.99 524.63 524.96 0.003313 5.05 249.19 176.95 0.46MAIN 3 100 Yr 781.00 519.99 524.78 525.14 0.003453 5.30 276.47 181.75 0.47
MAIN 2 50 Yr 695.00 520.34 524.13 523.69 524.57 0.005718 5.79 213.89 168.48 0.59MAIN 2 100 Yr 781.00 520.34 524.26 523.93 524.73 0.005905 6.05 236.18 169.51 0.60
MAIN 1 50 Yr 695.00 520.05 522.96 522.96 523.65 0.012398 7.07 151.74 163.80 0.83MAIN 1 100 Yr 781.00 520.05 523.11 523.11 523.81 0.011829 7.22 178.53 182.69 0.82