EA 03-0L2324 Yuba City, California Location Hydraulic Study Report Submitted to: Prepared by: November 2012
Table of Contents Executive Summary... iii Acronyms... v 1 General Description... 1 1.1 Project Description... 1 1.1.1 Existing Condition... 1 1.2 Project History... 2 1.2.1 Proposed Bridge Replacement... 2 1.3 Creek, Stream, and River Crossings... 2 1.4 Bridge Numbers... 3 1.5 Geographical References... 3 1.6 Traffic... 3 1.7 Traffic Interruptions for Base Flood (Q 100 )... 3 2 Hydrologic and Hydraulic Data... 7 2.1 Federal Emergency Management Agency Data... 7 2.2 Map of Floodplain... 7 2.3 Estimating Design Discharge... 8 2.4 Description of Flood Sources... 8 2.5 Hydraulic Assessment... 10 3 Project Evaluation... 13 3.1 Risk associated with implementation of the action... 13 3.2 Impacts on natural and beneficial floodplain values... 13 3.3 Support of probable incompatible floodplain development... 14 3.4 Measures to minimize floodplain impacts associated with the action... 14 3.5 Measures to restore and preserve the natural and beneficial floodplain values impacted by this action... 14 3.6 Practicability of proposed design to any significant encroachments... 15 3.7 Practicability of proposed design to any longitudinal encroachments... 15 3.8 Coordination with Local, State, and Federal Water Resources and Floodplain Management Agencies... 16 4 References... 17 Figures Figure 1. Location Map... 4 Figure 2. Vicinity Map... 5 Figure 3. Flood Insurance Rate Map for Marysville... 7 Figure 4. Flood Insurance Rate Map for Yuba City... 8 Tables Table 1. Bridge Hydraulic Summary... 11 Photos Photo 1. Railroad Bridge on the left and 5th Street Bridge on the left. Photo taken facing west. Piers shown in the photo are in the Feather River low-flow channel.... C-3 November 2012 i
Photo 2. 5th Street Bridge from the eastern embankment area. Photo taken facing southwest.... C-4 Photo 3. The railroad bridge is in the foreground and the 5th Street Bridge is in the background. Piers shown in the photo are in the low-flow channel. Photo taken facing northeast.... C-5 Photo 4. Piers on the eastern side. Photo taken facing northwest. Piers shown in the photo are within the 100-year floodplain.... C-6 Photo 5. Abutment on the eastern end. Photo facing northeast. Photo taken from the railroad bridge.... C-7 Appendices Appendix A Summary of Floodplain Encroachment... A-1 Appendix B General Plans... B-1 Appendix C Project Photographs... C-1 Appendix D HEC-RAS Results... D-1 Appendix D.1 Existing Condition 100-year Design Storm... D-3 Appendix D.2 Proposed Condition 100-year Design Storm... D-5 Appendix D.3 Existing Condition 200-year Design Storm... D-7 Appendix D.4 Proposed Condition 200-year Design Storm... D-9 November 2012 ii
Executive Summary This study presents the hydrologic, hydraulic, and floodplain risk assessments for the proposed 5 th Street bridge replacement over the Feather River in the City of Marysville (Yuba County) and Yuba City (Sutter County). The existing bridge shows scour at the piers, is susceptible to seismic liquefaction, and has extremely narrow shoulders. This report discusses floodplain impacts associated with the proposed replacement design. Dokken Engineering is the primary consultant for this project and WRECO is the hydraulic subconsultant responsible for hydraulic and scour analyses. Dokken Engineering prepared the proposed bridge replacement concept. There would be an insignificant change in the water surface elevation in the identified Feather River 100-year base floodplain from the bridge retrofit and replacement alternative. In addition, the bridge soffit elevation is higher than the estimated 100-year water surface elevation; therefore, there would be no traffic interruptions on 5 th Street/Bridge Street due to base flooding. Existing natural and beneficial floodplain values at the Feather River floodplain include open space and outdoor recreation. The proposed Project would not impact those natural and beneficial floodplain values. Environmental impacts as a result of construction activities can be mitigated with Best Management Practices (BMPs) measures. Implementation of BMPs and compliance with requirements from the Project s permit conditions would help to minimize impacts to the floodplain. The Project would be a transverse encroachment and is, therefore, not considered a longitudinal encroachment to the 100-year floodplain. November 2012 iii
This page is left intentionally blank. November 2012 iv
Acronyms AC Asphalt concrete ACOE Army Corps of Engineers ADT Average daily traffic BMP Best Management Practices Caltrans California Department of Transportation CIDH Cast-in-drilled hole CVFPB Central Valley Flood Protection Board DWR Department of Water Resources FEMA Federal Emergency Management Agency FHWA Federal Highway Administration FIRM Flood Insurance Rate Map FIS Flood Insurance Study HEC-RAS Hydrologic Engineering Center River Analysis System NAVD 88 North American Vertical Datum of 1988 NGVD 29 National Geodetic Vertical Datum of 1929 SPRR Southern Pacific Railroad Bridge TRLIA Three Rivers Levee Improvement Authority USED United States Engineering Datum November 2012 v
This page is left intentionally blank. November 2012 vi
1 GENERAL DESCRIPTION 1.1 Project Description The purpose of the (hereto known as the Project ) is to rehabilitate or replace the bridge between 5th Street in Marysville (Yuba County) and Bridge Street in Yuba City (Sutter County). The current bridge shows scour at the piers, is susceptible to seismic liquefaction, and has extremely narrow shoulders. The recommended rehabilitation option being proposed at this time is to replace the existing bridge. This report contains hydraulic analysis and bridge scour analysis of the proposed bridge replacement concept in order to provide the Project Team bridge engineers hydraulic data. The bridge crosses the Feather River, which is a principal tributary of the Sacramento River. The Feather River is 80 miles long. The river rises in three separate forks in the Sierra Nevada, which unite as arms of the Lake Oroville reservoir in the foothills 5 miles northeast of the City of Oroville. The combined stream flows generally south across the Sacramento Valley, past Oroville and Yuba City-Marysville, and joins Sacramento River approximately 20 miles north-northwest of Sacramento. 1.1.1 Existing Condition The existing bridge was constructed in 1958 as part of the December 1955 Flood Damage Replacement Project. The bridge has 22 spans over the Feather River and its floodplain. Two spans each extend over 2nd Street and the west levee. The bridge is supported mainly on hollow pier walls founded on clusters of battered and vertical piles. There is one lane in each direction. The existing bridge has shoulder widths of 1.0 feet on the left and right. The sidewalk/bikeway width is 9.8 feet on the westbound side of the bridge only. The roadway width is approximately 27.8 feet. The total bridge width is 42 feet. The bridge is rated 5 for the National Bridge Inventory Item 113 Scour Critical Bridges per the May 27 th, 2011 Caltrans Bridge Inspection Report. Approximately 23 feet south of the existing 5 th Street bridge is the historic Southern Pacific Railroad (SPRR) Bridge. The existing SPRR Bridge consists of two abutments and 39 piers per the Sacramento Northern Railway Co. record drawings for Railroad Bridge No. 136.53 across Feather River Marysville to Yuba City. The existing SPRR Bridge will remain in-place with no modifications made as part of this Project. The piers of the existing 5 th Street Bridge located within the channel are aligned with the existing SPRR Bridge. The piers of the existing 5 th Street Bridge that are located to the east of the main channel of the Feather River are aligned with every second pier (i.e. every other) of the existing SPRR Bridge piers. November 2012 1
1.2 Project History The 5 th Street Bridge was constructed in 1958. There is a history of Pier 4 having footing exposure issues. In 1997, the California Department of Transportation (Caltrans) had an Underwater Investigation performed, which discovered that the full depth of the pile cap and tremie seal of the upstream nose of Pier 4 were exposed. The pile cap and tremie seal at the upstream end were undermined. The Underwater Investigation recommended that the Local Agency in charge of maintenance of the structure protect the upstream end of Pier 4 from scour by placing some type of scour protection. This work had not been performed as of July 2003. This structure received a Condition State of 2 ( scour exists at the bridge site and if left unchecked could adversely impact the structural integrity of the bridge ) for the Element Level Inspection 361 Scour SMART flag (Caltrans, 2003). From the 2003 Bridge Inspection Report, the National Bridge Inventory Item 113 code was changed from 6 to 4. The previously appointed Code 6 is defined by the Federal Highway Administration (FHWA) as Scour calculation/evaluation has not been made. (FHWA, 2001) Code 4 for corresponds to the description that Bridge foundations determined to be stable for assessed or calculated scour conditions; field review indicates action is required to protect exposed foundations. (FHWA, 2001) Results of a scour review performed by the Caltrans Division of Structure Maintenance and Investigations Ratings Branch on 7/1/03 indicated that this structure is not scour critical under stream loading, but may be seismically vulnerable. In the Bridge Investigation Report in 2003, it was recommended that the Local Agency check for seismic instability of this structure resulting from permanent pile exposure. It was also recommended that the Area Bridge Maintenance Engineer monitor the amount of pile exposure on a regular biennial basis. There were 3 major floods that have caused failures on the levees near Marysville and Yuba City. These floods occurred in 1955, 1986, and 1997. The levees were not overtopped. In each case, sand boils had been observed at the toe (or outside of the toe) of the levee before failure. 1.2.1 Proposed Bridge Replacement The proposed bridge replacement would replace the existing 42 feet wide 22 span bridge with an 84 feet wide bridge. The proposed bridge would be 10 spans and supported on three column bents. Each pier section would have 3 columns. The proposed bridge will be located approximately 90 feet (along center of channel) from the existing SPRR Bridge, which is farther upstream than the existing 5 th Street Bridge. The proposed pier sections are not specifically aligned with the piers of the existing SPRR Bridge. See Appendix B for the General Plan layout sheets. 1.3 Creek, Stream, and River Crossings The Project site crosses the Feather River at 5 th Street (Marysville) and Bridge Street (Yuba City). November 2012 2
At the Project site, the Feather River is a very wide trapezoidal shape channel between levees. The main channel is under proposed Spans 2 and 3. The remaining spans are over the floodplain, which consists of grass fields and parking lots. 1.4 Bridge Numbers The State Bridge Number is 18C-0012 for the Feather River crossing. 1.5 Geographical References United States Geological Survey topographic quadrangles were used to locate the Project. The bridge is in the Yuba City, CA Quadrangle. WRECO utilized As-Built record drawings, Federal Emergency Management Agency (FEMA) documents, and an existing Hydrologic Engineering Center River Analysis System (HEC-RAS) model as vertical references for the Project. The vertical control for the As-Built record drawings are based on the United States Engineering Datum (USED). The vertical control for the FEMA documents and the HEC-RAS model are based on the National Geodetic Vertical Datum of 1929 (NGVD 29). Elevations from the As-Built record drawing were converted to the NGVD 29 datum by adding 3 feet. The proposed Project plans use the North American Vertical Datum of 1988 (NAVD 88). To convert the proposed data (NAVD 88) to be compatible with the HEC-RAS data (NGVD 29), a value of 2.28 feet was subtracted from the proposed design elevations. 1.6 Traffic The average daily traffic (ADT) in 1981 was 29,000. In 2001 the ADT was 35,000. The ADT in 2013 is predicted to be between 40,000 and 46,000. 1.7 Traffic Interruptions for Base Flood (Q 100 ) The base flood is that flood which has a one percent chance of occurrence in any given year (100-year flood). Potential flooding conditions for the proposed Project were evaluated based on the 100-year floodplains depicted on FEMA Flood Insurance Rate Maps (FIRMs). Based on available data, traffic interruptions due to the base flood would not be present at the Project site because the 100-year base flood is contained in the Feather River channel. In addition, the roadway elevation at the bridge is higher than the 100-year and 200-year water surface elevations at the Feather River crossing, which would eliminate traffic delays on the 5th Street Bridge due to base flooding. November 2012 3
Project Site Figure 1. Location Map Source: United States Geological Survey November 2012 4
Yuba River Project Site: 5 th Street/Bridge Street Feather River Figure 2. Vicinity Map Source: United States Geological Survey November 2012 5
This page is left intentionally blank. November 2012 6
2 HYDROLOGIC AND HYDRAULIC DATA 2.1 Federal Emergency Management Agency Data FEMA FIRMs for the Project site are shown, following, as Figure 3 for the City of Marysville and Figure 4 for the City of Yuba City. 2.2 Map of Floodplain Based on the FEMA FIRMs for the Project area, the 100-year floodplain is contained in the reach of the Feather River in the Project area. Levees on the Feather River protect the areas adjacent to the river from the 100-year flood. See Figure 3 and 4 below. Project Site Figure 3. Flood Insurance Rate Map for Marysville Source: Federal Emergency Management Agency November 2012 7
Project Site Figure 4. Flood Insurance Rate Map for Yuba City Source: Federal Emergency Management Agency 2.3 Estimating Design Discharge The drainage area at the Project site is approximately 4,000 square miles. Per the Frequency-Discharge, Drainage Area Curve from FEMA s Flood Insurance Study (FIS) for the City of Marysville, the 100-year design discharge is approximately 150,000 cubic feet per second at the Project site (FEMA, 2011). Design discharge from the MBK Engineers hydraulic model included hydrologic data based on a study by the United States Army Corps of Engineers for the Lower Feather River Floodplain Mapping Study in 2005 (MBK Engineers, 2006). At the Project site, the 100-year design discharge is 165,000 cfs and the 200-year design discharge is 192,000 cfs. 2.4 Description of Flood Sources The climatology of Marysville is not a significant factor in its flood problems. The climate is mild without extreme temperature variations with mean annual precipitation approximately 20.6 inches. Most of the annual precipitation in Marysville occurs between October and April with maximum storm intensities between December and March. A large portion of the annual precipitation occurs as snowmelt accumulates (FEMA, 2011). According to Central Valley Flood Protection Board, major high water events on the Feather River can occur between November 1 st and April 15 th from rain and snowmelt. Rain floods generally could occur between October and March and snowmelt floods generally could occur between April and June. However, in area of the Project, high November 2012 8
water events usually occur due to the result of a warm, heavy storm event coupled with the melting of snow pack in lower elevations. Minor flooding in Marysville can also originate from heavy rain or from ponding within the levee systems due to deficiencies in the city storm drain system (FEMA, 2011). Nine major floods on the Feather and Yuba Rivers have been documented since 1900 (1904, 1907, 1909, 1928, 1937, 1950, 1955, 1963, and 1964). The levee system sustained severe damage in the flood of 1955 with water going through the levees. The 1955 and 1964 floods are estimated as having a 200-year recurrence frequency on the Feather River, while the recurrence frequency on the Yuba River at Marysville was a 140-year in 1955 and a160-year in 1964 (FEMA, 2011). The Feather River is part of the Sacramento River Flood Control Project. Levees were incorporated in the Sacramento River Flood Control Project in 1917. These levees protect areas adjacent to the rivers from the estimated 100-year storm event, including the Project area. Lake Oroville on the Feather River, located upstream of the Project, is a major flood control structure to control total flows under the Sacramento River Flood Control Project. Lake Oroville is expected to contain the 100-year storm event and decrease downstream discharges in a 500-year storm event on the Feather River. New Bullards Bar Reservoir and Englebright Reservoir on the Yuba River, along with Oroville Dam on the Feather River, make up a coordinated three-dam system providing controls for the flow of the Feather and Yuba Rivers (FEMA, 1981). Levees adjacent to Feather River help to contain the flood waters within the levee system. There are no identified floodplains in the Project area, outside of the levee walls, because the levees provide protection from the 100-year storm event. It is important to note that the levees do not provide full protection nor do they completely eliminate the risk of flooding. The levees on either side of the Feather River, in the Project area, are accredited by FEMA as providing adequate protection for a 100-year storm event and the areas behind the levees are shown as such on the FEMA FIRMs for Yuba County, CA and Incorporated Areas (2011) and the City of Yuba City, California Sutter County (1984). The Marysville Levee Commission adopted the height of 81.2 feet (NAVD) as the official design elevation for levees based on historical flood events reaching that elevation (FEMA, 2011). After the construction of the Oroville Dam in 1964, only two major flood events have occurred in this area. In the winter of 1986, there was a failure of the left (southern) levee of the Yuba River just across from the City of Marysville inundating the communities of Olivehurst and Linda. In 1997, the Feather River levee broke north of the confluence of the Feather and Bear Rivers (south of the Project area), resulting in large areas of flooding. After these flood events, levee improvements were conducted to strengthen the levees in the area (FEMA, 2011). In 2000, the Department of Water Resources (DWR) and the Army Corps of Engineers (ACOE) reevaluated the levee systems for the Feather, Yuba, and Bear Rivers. In 2003, DWR, ACOE, and local government agencies identified freeboard deficiencies on the Bear River levee and November 2012 9
geotechnical issues with the Yuba River levee. They did not identify deficiencies with the Feather River levee (MBK Engineers, 2005). The Three Rivers Levee Improvement Authority (TRLIA) was created in 2004 through a joint powers agency agreement between the County of Yuba and Reclamation District 784 to finance and construct levee improvements surrounding the South Yuba County Area. Four work phases were identified with the goal of achieving the 200-year storm event protection. The four work phase projects are not in the Project vicinity. Phase 4 proposes to strengthen the levees along Feather River between Bear and Yuba Rivers, south of the Project (TRLIA, 2007). 2.5 Hydraulic Assessment MBK Engineers provided a copy of the Feather River HEC-RAS model as a basis for the hydraulic model for this Project. The model represents the Feather River and its tributaries from major reservoirs within the watershed basin to its confluence with the Sacramento River (2006). The Project is located between the Jack-Simmerly Slough tributary - Yuba River. The Jack-Simmerly Slough tributary - Yuba River Reach was isolated from the original model. The data from the original MBK Engineers model was used as the basis for the model used for this analysis. Additional river survey information was also added into the isolated reach model. The existing SPRR Bridge was updated to more accurately reflect the as-built design, and was included in both the existing and proposed hydraulic models. The peak design flows, water surface elevations, and average channel flow velocities for the location 2 feet upstream of the bridge and 100 feet upstream of the bridge are shown in Table 1. Bridge Hydraulic Summary and corresponding cross-sections have been provided in Appendix D of this report. Based on the hydraulic analyses, WRECO concluded that the proposed bridge could pass 1) the 100-year design storm under FHWA criteria and, for the most part, meet the Central Valley Flood Protection Board criteria of passing and 2) the 200-year design storm with adequate freeboard. The easterly abutment and approximately 25 feet of the soffit of the most easterly span clears the 200-year design water surface elevation and is 0.60 feet below the 3 feet of freeboard criteria. Per the proposed condition hydraulic model, the proposed bridge has little to no impact on the hydraulics at the existing SPRR Bridge during the design events. November 2012 10
Table 1. Bridge Hydraulic Summary Hydraulic Summary at 2 ft From Upstream Bridge Face Water Surface Elevation Average Channel Velocity Water Surface Elevation At 100 ft From Upstream Bridge Face Deck Elevation at Upstream Bridge Face 1 Soffit Elevation at Upstream Bridge Face 2 Design Alternative Design Storm Peak Flow (year) (cfs) (ft) (ft/s) (ft) (ft) (ft) Existing 100 165,000 74.02 5.44 74.14 84.06 76.78 Proposed Replacement 100 165,000 74.03 5.44 74.14 84.43 79.72 Existing 200 192,000 77.32 5.43 77.44 84.06 76.78 Proposed Replacement 200 192,000 77.33 5.43 77.44 84.43 79.72 Notes: 1 Deck elevations for the Existing and Proposed Replacement are at the lowest deck elevation of the bridge 2 Soffit elevations for the Existing and Proposed Replacement are at the lowest soffit elevation of the bridge 3 All the elevations listed in Table 1 are in NGVD 29. A factor of 2.28 feet shall be added to convert to the proposed design datum, which is NAVD 88. The hydraulic assessment is further detailed in the WRECO Bridge Design Hydraulic Study Report. November 2012 11
This page is left intentionally blank. November 2012 12
3 PROJECT EVALUATION The existing bridge is within the 100-year base floodplain associated with the Feather River. The proposed work would occur within the base floodplain. 3.1 Risk associated with implementation of the action The FHWA defines a significant encroachment as a highway encroachment and any direct support of likely base floodplain development that would involve one or more of the following construction or flood related impacts: 1) a significant potential for interruption or termination of a transportation facility which is needed for emergency vehicles or provides a community s only evacuation route; 2) a significant risk; or 3) a significant adverse impact on the natural and beneficial floodplain values (1994). 1. The Project does not have a significant potential for interruption or termination of a transportation facility which is needed for emergency vehicles or provides a community s only evacuation route. The proposed bridge will be no more susceptible to interruption than the Highway 20 bridge. The 5 th Street Bridge is the preferred and fastest emergency route from Yuba City to Rideout Hospital. The Project would significantly increase the reliability of 5 th Street due to addition of lanes. Traffic interruption for both the 100-year and 200-year events is not anticipated since the water surface elevation would be below the bridge deck. 2. The level of risk associated with the Project is low. Damage to the roadway from the 100-year event is not anticipated. The proposed work would not raise the water surface elevation in the floodplains by a significant amount. The encroachment on the floodplain would be minimal since the increase in water surface elevation in the floodplains would be minimal, as indicated by the HEC- RAS models; see Table 1. Bridge Hydraulic Summary. The proposed work would raise the water surface elevation in the floodplains by 0.01 feet. This change in water surface elevation would be insignificant. 3. Existing natural and beneficial floodplain values associated with the Feather River floodplain within or adjacent to the Project include open space and outdoor recreation. The proposed Project would not have a significant adverse impact on the natural and beneficial floodplain values. The risk associated with the Project is, therefore, minimal. 3.2 Impacts on natural and beneficial floodplain values Natural and beneficial floodplain values shall include, but are not limited to: fish, wildlife, plants, open space, natural beauty, scientific study, outdoor recreation, agriculture, aquaculture, forestry, natural moderation of floods, water quality maintenance, and groundwater recharge. November 2012 13
The piers of the existing bridge are within the 100-year base floodplain. Natural and beneficial floodplain values associated with the base floodplain include fish, wildlife, plants, open space, and outdoor recreation. The area immediately north of the bridge is a group of soccer fields. Measures to restore and preserve the natural and beneficial floodplain values are discussed in Section 3.5. 3.3 Support of probable incompatible floodplain development As defined by FHWA, the support of incompatible base floodplain development encourages, allows, serves, or otherwise facilitates incompatible base floodplain development, such as commercial development or urban growth. The Project would not encourage, allow, serve, or otherwise facilitate additional or incompatible base floodplain development. The floodplain encroachments would not be significant encroachments (as defined by FHWA in 23 CFR 650.105(q) of the Federal- Aid Policy Guide) because: 1. The Project does not have a significant potential for interruption or termination of a transportation facility which is needed for emergency vehicles or provides a community s only evacuation route. 2. The Project does not pose significant flooding risks. 3. The Project does not have impacts to natural and beneficial floodplain values. The approach roadways would conform to Shasta Street on the west end and to J Street on the east end. Therefore, the Project would not support incompatible base floodplain development. 3.4 Measures to minimize floodplain impacts associated with the action The Project would encroach onto the Feather River floodplains since the improvements would include the removal of the existing bridge and the installation of the new bridge. The effects on the water surface elevation would be minor. The Project would increase the 100-year water surface elevation by 0.01 feet. The Project would not adversely impact the Feather River floodplains. Appropriate Best Management Practices (BMPs) would be implemented to minimize storm water impacts. 3.5 Measures to restore and preserve the natural and beneficial floodplain values impacted by this action Natural and beneficial floodplain values within or adjacent to the Project include fish, wildlife, plants, open space, and outdoor recreation (see Section 3.2). There would be no November 2012 14
significant impacts to the natural and beneficial floodplain values. Environmental impacts would be a result of construction activities and can be minimized with measures such as re-vegetation, appropriate BMPs, or other requirements as part of the Project s environmental and permitting conditions. Permits or approvals would be required from ACOE, California Department of Fish and Game, United States Fish and Wildlife Service, National Oceanic and Atmospheric Administration Fisheries, California Regional Water Quality Control Board, and the Central Valley Flood Protection Board. 3.6 Practicability of proposed design to any significant encroachments As defined by FHWA, risk shall mean the consequences associated with the probability of flooding attributable to an encroachment. It shall include the potential for property loss and hazard to life during the service life of the bridge and roadway. The risks associated with the action are not significant. In the existing condition, the 100-year base floodplain does not extend beyond the Feather River and is contained within the levee system. The increase in water surface elevation associated with the replacement of piles and pile caps would not be significant enough to overtop the levee nor would the water surface elevation reach the soffit of the bridge. Improvement measures, such as flood walls, are being proposed along the east bank at the bridge to offer additional flood protection. 3.7 Practicability of proposed design to any longitudinal encroachments As defined by FHWA, a longitudinal encroachment is an action within the limits of the base floodplain that is longitudinal to the normal direction of the floodplain. A longitudinal encroachment is [a]n encroachment that is parallel to the direction of flow. Example: A highway that runs along the edge of a river is, usually considered a longitudinal encroachment. The requirement for consideration of avoidance alternatives must be included in a Location Hydraulic Study by including an evaluation and a discussion of practicability of alternatives to any significant encroachment or any support of incompatible floodplain development. The Project would be perpendicular to the direction of the Feather River flow (a transverse encroachment) and is, therefore, not considered a longitudinal encroachment to the 100-year floodplain. Therefore, alternatives have not been considered. November 2012 15
3.8 Coordination with Local, State, and Federal Water Resources and Floodplain Management Agencies The Cities of Marysville and Yuba City and the Counties of Sutter and Yuba and FEMA should review this report to determine if a floodplain map revision is necessary, due to the potential encroachment on the regulatory floodway. November 2012 16
4 REFERENCES California Department of Transportation. (2007). Structure Maintenance and Investigations: Local Agency Bridge List: Sutter County: City of Yuba City. California Department of Transportation. Structure Maintenance and Investigations. (2011). Bridge Inspection Report. Feather River Bridge, 18C0012, Fifth Street/Bridge Street between Marysville and Yuba City. Received from Dokken Engineering on March 26, 2012. California Department of Transportation. Structure Maintenance and Investigations. (2005). Bridge Inspection Report. Feather River Bridge, 18C0012, Fifth Street/Bridge Street between Marysville and Yuba City. Saved to PDF on October 31, 2007. Received from TRC Inc. on August 31, 2007. California Department of Transportation. Structure Maintenance and Investigations. (July 2003). Bridge Inspection Report. Feather River Bridge, 18C0012, Fifth Street/Bridge Street between Marysville and Yuba City. Saved to PDF on July 21, 2003. Received from TRC Inc. on August 31, 2007. California Department of Transportation. Structure Maintenance and Investigations. (2001). Bridge Inspection Report. Feather River BOH Bridge, 180009, SR 20 03- SUT-020-17.00-YC in Yuba City. Saved to PDF on November 29, 2001. Received from TRC Inc. on September 4, 2007. Dokken Engineering. (January 9, 2012). DRAFT Feasibility Study Report 5 th Street Bridge over the Feather River. Environmental Protection Agency. (1977). Floodplain Management, Executive Order No. 11988. 42 F.R. 26951. Federal Emergency Management Agency. (November 2010). The NFIP and Levees Systems Frequently Asked Questions. <http://www.fema.gov/library/viewrecord.do?id=2159> (Last Accessed: January 18, 2012) Federal Emergency Management Agency. (1984). FIRM: Flood Insurance Rate Map. City of Yuba City, California, Sutter County. Community Panel Number 060396 0005 B. (Effective Date: March 23, 1984). Federal Emergency Management Agency. (2011). FIRM: Flood Insurance Rate Map. Yuba County, California and Incorporated Areas. Map Number 06115C0340D. (Effective Date: February 18, 2011). Federal Emergency Management Agency. (2011). Flood Insurance Study. Yuba County, California, and Incorporated Areas. Community Numbers: 060427, 060460, 060428, and Unincoporated Areas. Flood Insurance Study Number: 06115CV000A (Effective Date: February 18, 2011). November 2012 17
Federal Highway Administration. (1994). Federal-Aid Policy Guide, Transmittal 12, 23 CFR 650 A. Gerwick, Ben C. Inc. (1956). Railroad Bridge No. 136.53 Across Feather River Marysville to Yuba City (Project Plans). MBK Engineers. (2007). HEC RAS 2006 Existing Condition. Existing2006.prj. MBK Engineers. (2006). Hydraulic and Hydrologic Documentation for FEMA Certification of the Three River s Levee Improvement Authority Project. Stirling, S. (SM&I Hydraulics ). (2006). Bridge Scour Evaluation Plan of Action. Feather River Bridge, 18009. Published by California Department of Transportation, Division of Maintenance: BIRIS. Three Rivers Levee Improvement Authority (TRLIA). (2007). Project Status Report. (Submitted to The Reclamation Board for the April 20, 2007, meeting). <http://www.trlia.org/agendasminutes.asp> (Last Accessed: January 18, 2012) United States Geological Survey. (2012). Peak Streamflow for the Nation. USGS 11407700 Feather R A Yuba City CA. <http://nwis.waterdata.usgs.gov/nwis/peak/?site_no=11407700&> (Last Accessed: January 18, 2012). United States Geological Survey. (2001). California: Seamless U.S.G.S. Topographic Maps (CDROM, Version 2.6.8, Part Number: 113-100-004). National Geographic Holdings, Inc. Wood Rodgers. (2004). Preliminary Seismic Vulnerability Study. November 2012 18
Appendix A Summary of Floodplain Encroachment November 2012 A
November 2012 A
This page is left intentionally blank. November 2012 A
Appendix B General Plans Note: All elevations on the following sheets are NAVD 88. November 2012 B
November 2012 B
November 2012 B
November 2012 B
November 2012 B
November 2012 B
November 2012 B
November 2012 B
November 2012 B
November 2012 B
Appendix C Project Photographs November 2012 C
November 2012 C
Photo 1. Railroad Bridge on the left and 5th Street Bridge on the right. Photo taken facing west. Piers shown in the photo are in the Feather River low-flow channel. November 2012 C
Photo 2. 5th Street Bridge from the eastern embankment area. Photo taken facing southwest. November 2012 C
Photo 3. The railroad bridge is in the foreground and the 5th Street Bridge is in the background. Piers shown in the photo are in the low-flow channel. Photo taken facing northeast. November 2012 C
Photo 4. Piers on the eastern side. Photo taken facing northwest. Piers shown in the photo are within the 100-year floodplain. November 2012 C
Photo 5. Abutment on the eastern end. Photo facing northeast. Photo taken from the railroad bridge. November 2012 C
November 2012 C
Appendix D HEC-RAS Results Appendix D.1 Existing Condition 100-year Design Storm Appendix D.2 Proposed Condition 100-year Design Storm Appendix D.3 Existing Condition 200-year Design Storm Appendix D.4 Proposed Condition 200-year Design Storm November 2012 D
November 2012 D
Appendix D.1 Existing Condition 100-year Design Storm November 2012 D
This page is left intentionally blank. November 2012 D
Appendix D.2 Proposed Condition 100-year Design Storm November 2012 D
This page is left intentionally blank. November 2012 D
Appendix D.3 Existing Condition 200-year Design Storm November 2012 D
This page is left intentionally blank. November 2012 D
Appendix D.4 Proposed Condition 200-year Design Storm November 2012 D
This page is left intentionally blank. November 2012 D