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Home My WebLink About2010 11 15 Floodplain Mod.pdf                                          Floodplain Modification  Submittal to the Town of Vail  November 15, 2010  Ever Vail Flood Plain Modification Permit 2 Table of Contents   I. Directory ....................................................................................................................3  II. Introduction ...............................................................................................................4  III. Floodplain Modification Application Submittal Requirements ..................................6  IV. Floodplain Modification Review Criteria ...................................................................7  V. Adjacent Addresses .................................................................................................12  VI. Attachments ............................................................................................................14          Ever Vail Flood Plain Modification Permit 3 I. Directory    Vail Resorts Development Company  137 Benchmark Road   Avon, CO 81620  (ph) 970‐754‐2544  Tmiller1@vailresorts.com    Mauriello Planning Group  PO Box 1127  Avon, CO 81620   (ph) 970.748.0920   dominic@mpgvail.com    AMEC Earth & Environmental   1002 Walnut, Suite 200   Boulder, CO 80302    (ph) 303.443.7839     Alpine Engineering, Inc.  P.O. Box 97  Edwards, CO 81632  (ph) 970.926.3373    Paladino and Company  (ph) 206.522.7600  www.paladinoandco.com    Kimley‐Horn and Associates, Inc   950 Seventeenth Street Suite 1050    Denver, CO 80202   (ph)  303.228.2300       LandWorks Design, Inc.   3457 Ringsby Court Suite 110    Denver, CO 80202    (ph)  303.433.4257      Peak Land Consultants, Inc.    1000 Lions Ridge Loop   Vail, CO 81657    (ph)  970.476.8644      CALLISON   1420 Fifth Avenue #2400  Seattle, WA 98101‐2343  (ph) 206.623.4646          Ever Vail Flood Plain Modification Permit 4 II. Introduction    As part of the overall Ever Vail project, the South Frontage Road will be relocated to the north immediately  adjacent and parallel to the eastbound lanes of I‐70.  This realignment will require the construction of a bridge  across Red Sandstone Creek directly south of the I‐70 right‐of‐way. As a result, a Town of Vail Floodplain  Modification Permit is required for the work that is needed to complete the road relocation.      The existing South Frontage Road crosses Red Sandstone Creek approximately 350 feet south of the proposed  location for the new crossing as shown in Figure 1 (USGS Quadrangle: Vail West, Co, Sections 6 and 7 of  Township 5S, Range 80W). The project area is shown in Figure 1.       Figure 1. Project Area for the New Frontage Road Bridge    A floodplain modification is defined by the Vail Town Code as follows:    A floodplain modification permit is a permit to allow construction of improvements and/or  modifications to the adopted floodplain for all other uses, improvements, or modifications to or within  the floodplain that do not fall within the guidelines of the floodplain use permit. However, no habitable  structures or improvements shall be allowed to be constructed within the floodplain (12‐21‐11E.2.a.).     Ever Vail Flood Plain Modification Permit 5   Existing Conditions at Red Sandstone Creek and the I‐70 CMP:      Ever Vail Flood Plain Modification Permit 6 III. Floodplain Modification Application Submittal Requirements     The Town Code requires the following submittal information for the review of a floodplain modification permit.      Requirement Comments Submitted  (1) Elevation of the lowest floor (including basement and  crawl space) of all new and substantially improved  structures within or adjacent to the floodplain.  These elevations have been submitted with the  overall Ever Vail submittal, and are also  included in this submittal.  YES  (2) Description of the extent to which any floodplain will  be altered including why, when, how, and when it will be  replaced back to its original configuration, and  addressing each relevant factor in subsection E3 of this  section.   This information is included in the attached  Hydraulic Analysis and each relevant factor  from Section E3 is addressed in Section V of this  submittal  YES  (3) Signature of the owners of all property subject to an  impact by the proposed improvement.    The property impacted by this application is  currently owned by Vail Resorts.  In the future,  it will be owned by CDOT.  CDOT and Vail  Resorts are aware of this application.  YES  (4) A site plan drawn to an engineering scale showing the  location, dimensions, and elevations of the proposed  landscape/grade alterations, existing and proposed  structures, relevant landscape/ topographic features,  and the location of the foregoing in relation to the 100‐ year floodplain. The floodplain line shall be provided on a  plan certified by a licensed professional engineer or land  surveyor.   The site plan has been completed by Landworks  Design and Alpine Engineering and AMEC Earth  & Environmental.    YES  (5) Detailed topographic cross sections provided by a  licensed professional surveyor of the area proposed to  be altered, showing existing and proposed conditions.     Peak Land Consultants has provided this  information. The topographic survey and  sections are included in this submittal.   YES  (6) Copy of all other necessary approved permits (i.e.,  building permit, public way permit, ACOE permit,  dewatering permit, DOW permit, CDHPE permit).     Required permits will be submitted as they are  approved. A 404 permit application is being  submitted to the ACOE in 2011. Under the  Colorado Discharge Permit System the following  will be submitted:  Stormwater Construction  Permit ; Construction Dewatering Wastewater  discharge Permit. No permits are required by  the Colorado Division of Wildlife but  consultation with the DOW has occurred in  regards to potential stream habitat  improvements for Red Sandstone Creek.   NA  (7) An engineered floodplain analysis of the impacts to  the floodplain prepared by a qualified licensed  professional engineer.     A Hydraulic Analysis is included in this  submittal.  YES  (8) Copy of submitted application for a conditional FIRM  and floodway revision through FEMA, if applicable.     A CLMOR will be submitted in 2011. A Letter of  Map Revision (LOMR) will be submitted to  FEMA within 6 months of the project  completion.  NA  (9) Environmental impact report, per chapter 12 of this  title.     An Environmental Impact Report is being  submitted as part of this submittal package.  YES  (10) Any additional information deemed necessary by  the floodplain administrator.  NA  Ever Vail Flood Plain Modification Permit 7 IV. Floodplain Modification Review Criteria    Chapter 21, Hazard Regulations, Vail Town Code provides the requirements and review criteria for a flood plain  modification permit.   The purpose of the flood hazard regulations is as follows:    To promote public health, safety and general welfare and to minimize public and private losses due to flood  conditions in specific areas by provisions designed to:  1. Protect human life and health;  2. Minimize expenditure of public money for costly flood control projects;  3. Minimize the need for rescue and relief efforts associated with flooding and generally undertaken at  the expense of the general public;  4. Minimize prolonged business interruptions;  5. Minimize damage to public facilities and utilities such as water and gas mains, electric, telephone  and sewer lines, streets and bridges located in floodplains;  6. Help maintain a stable tax base by providing for the sound use and development of flood prone  areas in such a manner as to minimize future flood blight areas;  7. Ensure that potential buyers are notified that property is in a flood area;  8. Ensure that those who occupy the floodplain assume the responsibility for their actions;  9. Protect the natural areas required to convey flood flows and retain flow characteristics; and  10. Obtain and maintain the benefits to the community of participating in the national flood insurance  program.    All floodplain modification permits are reviewed by the Floodplain administrator and the Planning and  Environmental Commission subject to the following criteria:  A.       The effects upon the efficiency or capacity of the floodway.   Our Analysis:   There is no designated floodway for Red Sandstone Creek. The impacts to the floodplain boundary  were evaluated using HEC‐RAS and are discussed in the attached engineering hydraulic analysis.   B.      The effects upon persons and personal property upstream, downstream and in the immediate  vicinity.  Our Analysis:  There will be no adverse effect upon persons or personal property upstream, downstream or in the  immediate vicinity. All new construction will be outside of the newly proposed floodplain. The water  surface elevations or velocities do not increase downstream or upstream of the project area and  therefore will not adversely impact persons or properties outside of the project area.   C. The effects upon the 100‐year flood profile and channel stability.     Our Analysis:  The impacts to the floodplain boundary were evaluated using HEC‐RAS. HEC‐RAS results show less than  a foot increase in water surface elevation profiles downstream of the project area. The floodplain  decreases in width downstream of the new South Frontage Road Bridge, and shortly downstream  returns to its existing configuration. The constriction of the floodplain is due to the channelization of  flow through the arched culvert.    FHWA design specifications were used to create the design details to protect the bridge and prevent  scour of the channel during high flow events.  A riprap energy dissipation basin has been designed to  force a hydraulic jump in order to dissipate energy from flow out of the I‐70 CMP. The channel bed will  Ever Vail Flood Plain Modification Permit 8 be lined with grouted riprap with a median diameter of 12 inches. A drop structure and scour pool will  be placed just downstream of the bridge to limit the downstream impact and limit further impacts to  Red Sandstone Creek. The area to the west of the creek, just downstream of the bridge, will be graded  to create a gradual slope from the southern edge of the retaining wall down to the creek. The area to  the east has a steep bank and will not be modified.     The attached engineering hydraulic analysis describes the impacts to the floodplain in depth and  includes design drawings with channel design details.  D.      The effects upon any tributaries to the main stream, drainage ditches and any other drainage  facilities or systems.  Our Analysis:  This design will not impact any tributaries to the main stream, drainage ditches or any other drainage  facilities.  A storm drain will collect water from the east side of the new South Frontage Road and  discharge to Red Sandstone Creek just downstream of the new bridge. Storm water will go through a  stormwater treatment system (Vortechs Model 16000) before discharging to Red Sandstone Creek. The  calculated discharge rate during a 100‐yr flow event is 24 cfs.   E. The danger to life and property due to flooding or erosion damage;   Our Analysis:  There will be no increase in the danger to life or property due to flooding or erosion damage associated  with the proposed project. There are no structures within the proposed floodplain. There should be  little or no erosion around the bridge since the channel will be armored to prevent scour during the  500‐yr flood event. The downstream channel will be armored with loose river cobble with a median  diameter of 6 inches, which is the estimated median diameter of the existing river cobble in this reach.  F. The susceptibility of the proposed improvement and its contents to flood damage and the effect of  such damage on the individual owner;   Our Analysis:  The channel below the bridge will be armored to protect the foundation from scour during a 500‐yr  flow event. The bridge footers will be protected from downstream erosion by a concrete cutoff wall  that is located at the downstream end of the bridge. Design drawings are included as an exhibit to the  attached engineering hydraulic analysis  G. The danger that materials may be swept onto other lands to the injury of others;  Our Analysis:  The I‐70 CMP restricts much of the debris from the headwaters. There is some debris at the site that  will be removed, but, for the most part, the amount of debris will remain the same. In addition, there  are no other landowners along Red Sandstone Creek. Therefore the probability of a downstream  landowner being impacted by debris along Red Sandstone Creek is unlikely.  H. The compatibility of the proposed use with existing and anticipated development;   Our Analysis:  The land adjacent to Red Sandstone Creek Floodplain is currently zoned   Arterial Business District to the west and Lionshead Mixed Use – 2 to the east of the creek. The  proposed zoning for the entire site is Lionshead Mixed Use – 2.   The relocation of the South Frontage  Road consolidates the impacts to the creek (both existing and proposed) to one area, allowing for the  remainder of the creek (downstream to Gore Creek) to be improved and restored, and to create a  community amenity.  A complete analysis of the anticipated development of Ever Vail is included in this  submittal package.  Ever Vail Flood Plain Modification Permit 9 I. The safety of access to the property in times of flood for ordinary and emergency vehicles;   Our Analysis:  None of these bridges will be flooded. Emergency Vehicles can access the east side of property utilizing  the South Frontage Road and Forest Road.  Emergency Vehicles can access the west side of property  utilizing the South Frontage Road.   J. The costs of providing governmental services during and after flood conditions including maintenance  and repair of streets and bridges, and public utilities and facilities such as sewer, gas, electrical and  water systems;   Our Analysis:  These costs will remain the same.  There are no new utilities located within the existing or proposed  floodplain boundary. All new utilities will be located above the floodplain and will be accessed via the  new South Frontage Road Bridge.  K. The expected heights, velocity, duration, rate of rise and sediment transport of the floodwaters and  the effects of wave action, if applicable, expected at the site;   Our Analysis:  The impacts to the floodplain boundary were evaluated using HEC‐RAS. HEC‐RAS results show less than  a foot increase in water surface elevation profiles downstream of the project area. The floodplain  boundary decreases in width a short distance downstream of the new South Frontage Road Bridge and  shortly downstream returns to its existing configuration. The attached Engineering Hydraulic Analysis  describes the impacts to the floodplain in depth.  L. The effect the proposed changes will have any adverse environmental effect on the watercourse  including, without limitation, erosion of stream banks and stream side trees and vegetation and  wildlife habitat;   Our Analysis:  The realignment of Red Sandstone Creek to accommodate the new South Frontage Road Bridge will  have a small environmental effect on the watercourse under the new bridge. The Red Sandstone Creek  stream ecosystem in the vicinity of the Site has been diminished due to channelized stream conditions  and steep banks caused by fill material from neighboring parcels and the I‐70 CMP.  The stream bottom  consists of boulders and cobbles and provides limited habitat for several species of fish.  According to  the CDOW, the following species of fish could be found in Red Sandstone Creek below the I‐70 culvert:  brown trout, rainbow trout, brook trout, cutthroat trout, and sculpin (Andree, pers. comm.).  However,  resting and spawning areas for fish are extremely limited in this section of Red Sandstone Creek,  especially during spring runoff and critical low flow periods in the late summer, fall, and winter.      There are wetlands adjacent to Red Sandstone Creek; however, infringement from development has  degraded riparian habitat, which is limited to a narrow band along the stream banks.  All wetland  impacts will be mitigated as required by the Army Corps of Engineers.  A wetland mitigation plan and a  404 Permitting will be completed in 2011.    The proposed floodplain will not cause an increase in erosion of stream banks. Many of the trees in the  vicinity will be preserved. Some trees have been designated for removal due to their deteriorating  health, and one tree will be removed to accommodate the new channel alignment. The vegetation that  is impacted during construction will be revegetated as defined in the Landscaping plans created by  Landworks Design.       Ever Vail Flood Plain Modification Permit 10 M. The necessity to the facility of a waterfront location, where applicable;   Our Analysis:   A variety of alternatives were evaluated to select an optimal Creek alignment and set of structures that  would minimize floodplain impacts downstream of the proposed South Frontage Road Bridge crossing  Red Sandstone Creek.       In order to span the existing floodplain, a 120’ spanned bridge would be required to traverse the  floodplain. This alternative was not chosen due to the associated cost and aesthetic considerations.  Various bridge spans were evaluated to determine the most appropriate size and style available that  will appropriately convey and manage flow through the new structure.   A single span bridge with 42‐ foot clear opening was selected as the most appropriate, cost effective and aesthetic alternative.      The span of the proposed bridge was developed using HEC‐RAS to model various stream geometries  and bridge span options to identify a bridge span length that would not significantly impact water  surface elevations of the Creek downstream. Once this span length was determined the remaining  design characteristics were determined through an iterative process using Federal Highway  Administration (FHWA) standards and HEC RAS modeling. The primary design parameters were based  on the following objectives:  maintain channel stability by armoring the new channel under the bridge  to prevent scour during a 500‐yr flood event, include channel geometry that is similar to the existing  stream geometry, and provide sufficient channel conveyance capacity to minimize changes to the  existing 100‐year water surface elevation.  N. The availability of alternative locations, not subject to flooding or erosion damage, for the proposed  use;   Our Analysis:  There is no alternative location because of the necessity to cross Red Sandstone Creek.   O. The relationship of the proposed use to the comprehensive plan for that area.   Our Analysis:  The relocated South Frontage Road is identified as a possibility in the Lionshead Redevelopment Master  Plan for the West Lionshead area. The existing alignment includes a small radius curve in the road,  creating conditions that are unsafe in that area.  The Lionshead Redevelopment Master Plan  contemplated a South Frontage Road alignment which parallels I‐70, but returns to the original location  at Red Sandstone Creek.  This alignment was not acceptable to CDOT, as it maintains an unsafe bend in  the road.  CDOT has indicated that the only acceptable alignment parallels I‐70 for the entire distance  of the West Lionshead area, joining back up to the existing alignment just west of the existing Glen  Lyon Office Building.  In addition, the alignment contemplated by the Lionshead Redevelopment  Master Plan would have required significant disturbance to Red Sandstone Creek, because the  proposed bridge would have run parallel to the creek for a distance.  In conclusion, the alignment of the  South Frontage Road and the floodplain modification required are in compliance with the Lionshead  Redevelopment Master Plan and associated Transportation Master Plans for the traffic network in the  Town of Vail.    The following findings shall be made before granting of a floodplain permit:  (1) That the proposed use or modification adequately addresses the findings in subsection E3a of this  section, as determined by the floodplain administrator, unless the applicant can demonstrate that  one or more of the standards is not applicable, or that a practical solution consistent with the public  interest has been achieved;    Ever Vail Flood Plain Modification Permit 11 (2) That the proposed use or modification is consistent with the adopted goals, objectives and policies  outlined in the Vail comprehensive plan and compatible with the development objectives of the town;  and    (3) That the proposed use or modification is compatible with and suitable to adjacent uses and  appropriate for the surrounding areas; and    (4) That the proposed use or modification promotes the health, safety, morals, and general welfare of  the town and promotes the coordinated and harmonious development of the town in a manner that  conserves and enhances its natural environment and its established character as a resort and  residential community of the highest quality.  Ever Vail Flood Plain Modification Permit 12 V. Adjacent Addresses  210312109003  GLEN LYON OFFICE BUILDING  C/O ANDREW D. NORRIS  1000 S FRONTAGE RD W STE 200  VAIL, CO 81657    210312100005  000934 FRONTAGE RD  VAIL CORPORATION  PO BOX 959  AVON, CO 81620‐0959    210312100004   001031 FRONTAGE RD  SOHO DEVELOPMENT LLC  950 17TH ST STE 1600  DENVER, CO 80202     210312100002  000953 FRONTAGE RD  SOHO DEVELOPMENT LLC  950 17TH ST STE 1600  DENVER, CO 80202    210312124001  000923 FRONTAGE RD W  VAIL CORP  PO BOX 7  VAIL, CO 81658    210312109004  SUB:GLEN LYON SUBDIVISION LOT:39‐2  ROBERT J. ROSEN 2005 QPRT  NANCY ROSEN 2005 QPRT  1127 LAKE AVE  GREENWICH, CT 06831    210312109005   ORRAS, IGNACIO  777 POST OAK BLVD 550   HOUSTON, TX 77056    210107216001  000846 FOREST RD  EAGLE RIVER WATER & SANITATION DIST  846 FOREST RD  VAIL, CO 81657    210107200001   210312109002   210312100010  210107200001  210106302004  210107218002  210107218001   TOWN OF VAIL  C/O FINANCE DEPT  75 S FRONTAGE RD  VAIL, CO 81657    210107217004  000825 FOREST RD  GORE CREEK PLACE LLC  PO BOX 7  VAIL, CO 81658    210107217002  000728 LIONSHEAD CIR  VAIL CORP  PO BOX 7  VAIL, CO 81658    000710 LIONSHEAD CIR  VAIL SPA CONDOMINIUM ASSOC  710 W LIONSHEAD CIR  VAIL, CO 81657    DANN PETER  ‐ Registered Agent  PO BOX 5480  AVON, CO 81620      001000 LIONS RIDGE LOOP  VAIL RUN RESORT COMMUNITY  1000 LIONS RIDGE LOOP  VAIL, CO 81657    Vail Run Resort Community Assoc Inc  William I Fleischer  ‐ Registered Agent  1000 LIONSRIDGE LOOP   VAIL, CO 81657      210107217002  RCR Vail LLC  390 INTERLOCKEN CRESCENT STE 1000   BROOMFIELD , CO 80021    Gore Creek Place LLC  390 Interlocken Crescent,   Broomfield, CO 80021    210107222004   JPSSE VAIL IMMOBILIERE LLC  RUBEN DARIO 115 TORRE 2   602 MEXICO D.F. CP 11580   MEXICO    210107222003   3 GCP INC  AV CHAPULTEPEC 18  MEXICO DF 06640  MEXICO     210107222002   MARK GREENHILL REV TRUST ‐ ELIZABETH GREENHILL REV  TRUST ‐ MARK GREENHILL FAMILY DESCENDANTS TRUST  153 SHERIDAN RD  WINNETKA, IL 60093     210107222001  CAREY, ROBERT B.  6912 E HUMMINGBIRD LN  PARADISE VALLEY, AZ 85253      Ever Vail Flood Plain Modification Permit 13 210107222007   SHARE SYNDICATE XIII LLC  ALISON BUCHHOLTZ  675 LIONSHEAD PL   VAIL, CO 81657    210107222008   JANICE SAUVAGE TRUST NO 1  8650 W TROPICANA AVE 208  LAS VEGAS, NV 89147    210107222006   SCHICIANO, KENNETH  43 HIGHGATE RD  WELLESLEY, MA 02481    210107222005   5 GCP INC  AV CHAPULTEPEC 18 COL DOCTORES  MEXICO DF  MEXICO     2103‐014‐01‐068  TELLEEN, DANIEL E.  122 E MEADOW DR  VAIL, CO 81657    2101‐063‐03‐015  JOSEPH O. BROUGHTON TESTAMENTARY TRUST  240 ASH ST  DENVER, CO 80220    2101‐063‐03‐016  BROUGHTON, JOSEPH O., JR & LINDA K.  240 ASH ST  DENVER, CO 80220    2101‐063‐03‐014  RICHARD E. & MARTHA GRIFFITH DEAN TRUST, RICHARD E. &  MARTHA GRIFFITH DEAN TRUSTEES  PO BOX 970  TONGANOXIE, KS 66086    SIMBA RUN CONDOMINIUM ASSOCIATION  Farrow Hitt  1100 N FRONTAGE RD  VAIL, CO 81657    BREAKAWAY WEST ASSOCIATION  Christine A. Spaeth  PO Box 3717,   Eagle, CO 81631    BREAKAWAY WEST ASSOCIATION  P.O. Box 1743,   Vail, CO 81658    SANDSTONE 70 CONDOMINIUM ASSOCIATION, INC.  Vail Tax & Accounting, Inc.  BOX 5940  AVON, CO 81620    SANDSTONE 70 CONDOMINIUM ASSOCIATION, INC.  PO BOX 1679  AVON, CO 81620    CDOT  4201 E. ARKANSAS AVENUE  DENVER, CO 80222    MAURIELLO PLANNING GROUP, LLC  POST OFFICE BOX 1127  AVON, CO 81620    2101‐072‐11‐032  VAIL RESORTS DEV  THE FIXED ASSETS DEPARTMENT  390 INTERLOCKEN CRESCENT STE 1000   BROOMFIELD , CO 80021    2101‐072‐23‐001  WDL Vail Condominium Association, Inc.  Graham Frank  Post Office Box 959,  Avon, CO 81620     The Gore Creek Place Homeowner's Association  728 W. Lionshead Circle  Vail, CO 81657  Ever Vail Flood Plain Modification Permit 14 VI. Attachments      Attachment A:  Engineering Floodplain Analysis     South Frontage Road Bridge at Red Sandstone Creek    Attachment B:  Hydraulic Design Drawings      South Frontage Road Bridge at Red Sandstone Creek Engineering Floodplain Analysis Prepared for Vail Resorts Development Company Prepared by AMEC Earth & Environmental 1002 Walnut Street Suite 200 Boulder, Colorado 80302 P: 303.443.7839 F: 303.442.0616 www.amec.com November 15, 2010 Floodplain Modification Permit – Engineering Floodplain Analysis South Frontage Road Bridge at Red Sandstone Creek 2 AMEC Earth & Environmental Important Notice This floodplain analysis report was prepared exclusively for Vail Resorts Development Company (VRDC) by AMEC Earth & Environmental, Boulder Office (AMEC). The quality of information, conclusions, and estimates contained herein are consistent with the level of effort involved in AMEC’s services, and are based upon: i) information available at the time of preparation; ii) data supplied by outside sources; and iii) the assumptions, conditions and qualifications set forth in this report. This report is intended to be used by Vail Resorts Development Company (VRDC) only, subject to the terms and conditions of its contract with AMEC. Any other use of, or reliance on, this report by any third party is at that party’s sole risk. Client Contact: Sara Born Doug Laiho AMEC Earth & Environmental, Inc. Boulder Office 1002 Walnut Street, Suite 200 Boulder, Colorado 80302 T. 303.443.7839 Doug.Laiho@amec.com saraborn@alpinehydroecology.com Floodplain Modification Permit – Engineering Floodplain Analysis South Frontage Road Bridge at Red Sandstone Creek 3 AMEC Earth & Environmental TABLE OF CONTENTS 1.0 INTRODUCTION.........................................................................................4 2.0 FLOODPLAIN ENGINEERING ANALYSIS................................................4 2.1 EVALUATION OF THE EXISTING FLOODPLAIN BOUNDARY AND DEVELOPMENT OF A NEW EFFECTIVE HEC-RAS MODEL...................5 2.2 NEW EFFECTIVE HEC-RAS MODELING RESULTS SUMMARY............7 2.3 DEVELOPMENT OF A HEC-RAS MODEL FOR THE PROPOSED CONDITIONS.............................................................................................8 2.4 PROPOSED CONDITIONS – HEC-RAS MODELING RESULTS SUMMARY...............................................................................................10 3.0 CONCLUSIONS........................................................................................12 4.0 ENGINEERING STATEMENT..................................................................13 Exhibits Exhibit A: Plan View of Floodplain Boundaries: existing FEMA, new effective and proposed Exhibit B: HEC-RAS tabular results: New Effective Model Exhibit C: South Frontage Road Bridge Hydraulic Design Drawings Exhibit D: HEC-RAS tabular results: Proposed Conditions Exhibit E: HEC-RAS Cross Sections: Proposed Conditions Attachments Attachment A: Existing FEMA floodplain boundary as produced by J.F. Sato and Associates Attachment B: Peak Land Consultants Survey, October 8, 2008 Floodplain Modification Permit – Engineering Floodplain Analysis South Frontage Road Bridge at Red Sandstone Creek 4 AMEC Earth & Environmental 1.0 Introduction Vail Resorts Development Company, in conjunction with the Town of Vail is planning on moving the I-70 South Frontage Road in West Lionshead to the north, immediately adjacent and parallel to the eastbound lanes of I-70. This realignment will require the construction of a bridge across Red Sandstone Creek, directly south of the I-70 right-of- way. The purpose of this report is to address and evaluate the hydraulic impacts associated with moving the South Frontage Road. The proposed project for the new South Frontage Road Bridge will require realignment and reconstruction of the Creek channel from the I-70 CMP discharge location to a location approximately 185 feet downstream. The proposed bridge will be constructed using a Con/Span arch with a clear span of 42-feet. The Con/Span arch is the structural component of the bridge that will span the creek. The bridge will be 99.35 feet wide. The span of the proposed bridge was developed using HEC-RAS to model various stream geometries and bridge span options to identify a bridge span length that would not significantly impact water surface elevations or velocities of the Creek downstream of the proposed bridge. Once this span length was determined the remaining design characteristics were determined through an iterative process using Federal Highway Administration (FHWA) standards and HEC-RAS modeling. The primary design parameters were based on the following objectives: maintain channel stability by armoring the new channel under the bridge to prevent scour during a 500-yr flood event, include channel geometry that is similar to the existing stream geometry, and provide sufficient channel conveyance capacity to minimize changes to the existing 100-year water surface elevations downstream. The project area discussed in this report starts at the discharge location for the existing I-70 CMP and ends 185-ft downstream, where the new channel meets grade with the existing channel morphology. 2.0 Floodplain Engineering Analysis The intent of the engineering analysis is to review the existing Flood Insurance Study (FIS) floodplain boundary, define a new effective Base Flood Elevation (BFE) using more recent topographic data, and define a new BFE for the proposed bridge design. The HEC-RAS files used to model the existing floodplain were acquired from FEMA and modified to represent more recent and accurate survey data. The original FEMA HEC- RAS model will be referred to as the FIS HEC-RAS model. The model used to model the new effective BFE will be referred to as the effective HEC-RAS model. The existing Flood Insurance study (08037CV000A) for Red Sandstone Creek was adopted by FEMA on December 4, 2007. The flood hazard area is depicted on Eagle County, Colorado FIRM Panel 0837C046D as shown in Figure 2 (and included in Attachment A). The existing floodplain zone is defined as Zone AE floodplain. The existing FEMA FIRM represents modeling of Red Sandstone Creek from the confluence with Gore Creek to approximately 2,900 feet upstream, just past Potato Patch Drive. Floodplain Modification Permit – Engineering Floodplain Analysis South Frontage Road Bridge at Red Sandstone Creek 5 AMEC Earth & Environmental Figure 1. Existing FIRM panel for Red Sandstone Creek 2.1 Evaluation of the Existing Floodplain Boundary and development of a New Effective HEC-RAS Model The cross section geometry modeled in FIS HEC-RAS model was examined for accuracy and compared to more recent survey data to verify the precision of the geometry data in the vicinity of the project. Upon comparing the FIS cross sections to more recent topographic data, discrepancies were revealed. Because of the numerous discrepancies between the FIS HEC-RAS geometric data and existing topographic data, Vail Resorts and Development Company (VRDC) contracted Peak Land Consultants to resurvey the cross sections at the same locations along Red Sandstone Creek. Cross sections 406.5, 406, 405.5, 405.3, 405, 404, 403, 402.5, 402, and to 401.5 were surveyed on October 7, 2008. Three new cross sections were also surveyed at this time. This was done to provide more detail for the new effective floodplain boundary analysis. Two of the new cross sections are located between cross Floodplain Modification Permit – Engineering Floodplain Analysis South Frontage Road Bridge at Red Sandstone Creek 6 AMEC Earth & Environmental sections 404 and 405. These new cross section identification numbers are 404.5 and 404.25. The third cross section is located just downstream of cross section 405.5, located just downstream of the I-70 CMP discharge. This location was chosen because the cross section ID 405.5 intersects the culvert wing walls, and thus inaccurately represents the stream geometry downstream of the I-70 CMP discharge. The cross section locations are shown in plan view in Exhibit A, and a hard copy of the design drawings are located in Attachment A. 2.1.1 Mannings n-Values Manning’s n-values for the main channel and overbank portions of Red Sandstone Creek were not changed for the new effective model. The Manning’s n-values used are 0.04 and 0.05 for the main channel and the overbank areas, respectively. This is congruent with field observations and aerial photographs. Red Sandstone creek is generally narrow and the streambed consists of cobbles and small boulders and the floodplain is moderately vegetated. 2.1.2 Hydrology The hydrology used in the existing FIS model was adopted and used in the new effective model. 2.1.3 Boundary Conditions – Flow Regime Boundary conditions were changed for the new effective baseline model. The existing FEMA model used a downstream boundary condition of 0.04 feet/feet. The model was run using the sub-critical flow regime. The downstream boundary condition for the new effective model was set at normal depth, based on the average channel slope of 0.05 feet/feet. 2.1.4 Culvert and Bridge Data Entrance and exit loss coefficients were not changed at stream cross sections for the new effective baseline model. Entrance and loss coefficients are 0.1 and 0.3 at stream cross sections. Entrance and loss coefficients at the culverts are 0.5 and 1.0, respectively. The Entrance and loss coefficients at the existing South Frontage Road (Section ID’s 402.5 and 402) have been changed to 0.3 and 0.5, respectively. 2.1.5 Cross Sectional Geometry The new cross sectional data from the topographic survey was entered into the new effective HEC-RAS model. The most notable changes to the geometry data are listed below. 1. Sections 406.5 and 406 have updated horizontal geometry to show flow in the horizontal plane, rather than rising above I-70. The FIS HEC-RAS model showed flow overtopping I-70. 2. The I-70 CMP invert elevation on the north side of I-70 has been changed to 8120.3 feet. The FIS CMP invert elevation value was 8124.3 feet. 3. The CMP invert elevation on the south side of I-70 was changed to 8107.90 feet. The FIS CMP invert elevation measurement was 8105.00 feet. 4. Cross section 405.3 was added to represent the actual stream geometry downstream of the I-70 CMP. The new cross section is located 5 feet Floodplain Modification Permit – Engineering Floodplain Analysis South Frontage Road Bridge at Red Sandstone Creek 7 AMEC Earth & Environmental downstream of cross section ID 405.5 This new location was added because the existing section (ID 405.5) shows the wing walls of the CMP, and misrepresents the general existing channel geometry in that reach. 5. Cross sections 404.5 and 405.25 were added to provide more floodplain elevation data downstream of the new location for the South Frontage Road Bridge. 6. The CMP diameter has been changed to 7 ft. The culvert diameter in the FIS HEC-RAS model was 6 ft. 2.2 New Effective HEC-RAS Modeling Results Summary The new effective HEC-RAS model was run using geometry data created from the most recent survey. Model results in tabular format for the new effective model are presented in Exhibit B. Table 1 provides a summary table to compare the FIS and new effective water surface elevations and velocities during a 100-yr event. Table 1. Water Surface Elevations and Velocities from FIS HEC-RAS model and the new effective HEC-RAS model. FIS Model Results New Effective Model Results River Station ID W.S. Elev (ft) Vel Chnl (ft/s) W.S. Elev (ft) Vel Chnl (ft/s) 408 8158.02 7.66 8158.02 7.66 407 8140.04 7.63 8140.04 7.62 406.5 8139.2 0.93 8135.03 1.48 406 8139.21 0.84 8135.02 1.73 405.7 I-70 Culvert I-70 Culvert I-70 Culvert I-70 Culvert 405.5 8109.39 8.8 8110 10.02 405.3 n/a n/a 8108.82 8.45 405.25 n/a n/a 8107.62 3.1 405 8107.12 6.13 8106.77 5.9 404.5 n/a n/a 8099.98 6.16 404.25 n/a n/a 8097.96 6.08 404 8096.39 7.32 8096.35 7.68 403 8088.34 8.19 8089.03 6.51 402.5 8088.56 4.62 8089.06 4.76 402.3 Existing Frontage Rd. Bridge Existing Frontage Rd. Bridge Existing Frontage Rd. Bridge Existing Frontage Rd. Bridge 402 8085.54 7.7 8085.42 7.71 401.5 8083.53 7.54 8083.16 7.55 401 8077.2 5.75 8075.96 6.26 *An n/a value indicates those cross sections do not exist in the specified model. Floodplain Modification Permit – Engineering Floodplain Analysis South Frontage Road Bridge at Red Sandstone Creek 8 AMEC Earth & Environmental The water surface elevations and velocities changed at various cross section locations. The most notable changes are: 1. The water surface elevations at section ID’s 406 and 406.5 (north of I-70) decrease in elevation by approximately 4 feet. This is most likely due to the increased representation width of the floodplain at the cross sections. The existing FIS model truncated the sections and therefore there was no representation of flow in the horizontal plane 2. Section ID 405.5 shows a higher water surface elevation in the new effective model. This is most likely a result of the FIS model not representing the wing walls, while the new effective geometry represents the wing walls, and the immediate downstream stream morphology. 3. The water surface elevation at section ID 405 is lower in the new effective model. This is mostly likely a result of more detailed geometry that shows a more incised channel. 2.3 Development of a HEC-RAS model for the Proposed Conditions The proposed bridge will be constructed using a Con/Span arch with a clear span of 42- feet. The Con/Span arch is the structural component of the bridge that will span Red Sandstone Creek. The bridge will be 99.35 feet wide. The I-70 CMP will be shortened by 10 feet. Each end of the bridge will require a concrete headwall. The upstream headwall will be located adjacent to the east bound lanes of I-70 and will retain the adjacent slope. In addition, this will provide an opening for the existing I-70 CMP to penetrate the wall. The CMP will extend 1.9 feet beyond the edge of the upstream headwall to prevent seepage behind the retaining wall. The Con/Span arch will have 10 additional inches of vertical clearance over the I-70 CMP. In order to convey flow through the Con/Span arch, the channel bed for Red Sandstone Creek is being adjusted to flow through the bridge. FHWA design specifications were used to create the design details to protect the bridge and prevent scour of the channel during high flow events. The channel configuration is based on the need to protect the bridge during high flow events and effectively manage flow during low flow events. A riprap energy dissipation basin has been designed to prevent scour and dissipate energy from flow out of the I-70 CMP. The channel bed will be lined with grouted riprap with a median diameter of 18 inches. A drop structure and scour pool will be placed just downstream of the bridge to minimize the longitudinal grade and limit further downstream impacts to Red Sandstone Creek. Detail design computations are included in the CDOT Hydraulic Report. The area to the west of the creek, just downstream of the bridge, will be graded to create a gradual slope from the southern edge of the bridge face down to the creek. Note that the existing South Frontage Road Bridge will not be removed as part of this project. The area will continue to be accessed via the existing South Frontage Road until the Ever Vail development is at or near completion. Design drawings for the proposed project are located in Exhibit C. Floodplain Modification Permit – Engineering Floodplain Analysis South Frontage Road Bridge at Red Sandstone Creek 9 AMEC Earth & Environmental The new effective HEC-RAS model was modified to reflect the new South Frontage Road Bridge location, the realignment of Red Sandstone Creek, and the associated downstream grading changes. A project boundary has been defined by identifying the cross sections where the water surface elevations and velocities have not been impacted by the proposed changes, i.e. the water surface elevation profiles match existing. The project boundaries are cross sections 407 and 402. Cross section ID 407 is located 3 cross sections and 211 feet upstream of the I-70 CMP inlet. Cross section ID 402 is located immediately downstream of the existing frontage road bridge. The water surface elevations and velocities return to existing values at or before these project boundary sections. A new grading plan was created to represent the proposed changes associated with the new South Frontage Road Bridge. The new grading plan was used to create a 3- dimensional surface and cross sections using RiverTools, a program extension to Civil 3D. This program creates cross sections in user specified locations and allows the user to export the geometry into HEC-RAS, as an .sdf file. These cross sections are labeled in blue in Exhibit A. This data was then combined with the new effective HEC-RAS model to compute the impacts to the water surface elevations within the proposed project area. A summary of the primary design changes incorporated into the proposed HEC-RAS model and associated geometry are listed below. 1. The downstream end of the I-70 CMP has been cut back 10 ft. The culvert will now discharge directly into the 42 ft Con/Span arch. The new culvert invert elevation will be 8108.30 feet. 2. All cross-sectional data between the I-70 CMP and the southern edge of bridge have been replaced with new geometry and numbered accordingly. This geometry represents the new riprap basin and the new stream geometry. Note that the existing HEC-RAS sections were not always perpendicular to the flow line. The geometry data used for the proposed conditions model uses cross sections that are perpendicular to the flow line. For this reason it is difficult to directly compare before and after water surface elevations based on cross section ID’s and location alone. When a cross section line from the proposed model was crossing a cross section line from the new effective model it was given a section ID value 0.01 high or lower. If the proposed cross section centerline was above the existing section line then the value was higher and vice versa. For comparison purposes the water surface elevation for the proposed conditions was interpolated based on the plan view of floodplain boundary. Refer to Exhibit A for further clarification. 3. The width of the proposed bridge is 99.35-ft. For modeling purposes the bridge was shorted to 49 feet long and placed downstream of the I-70 CMP stilling basin. This was done so that the stilling basin could be represented in the hydraulic model. HEC-RAS will not allow the modeler to enter a bridge and details for a stilling basin simultaneously. Note the upstream section of the bridge was modeled by creating stream geometry to represent the walls of the bridge. 4. New cross sections were added downstream of the proposed bridge to represent the drop structure, scour pool, and grading downstream of the bridge. Floodplain Modification Permit – Engineering Floodplain Analysis South Frontage Road Bridge at Red Sandstone Creek 10 AMEC Earth & Environmental The hydraulic attributes are the same as those used in the new effective model. The following assumptions were used:  The Manning’s n value used to model the reach through the bridge is 0.03. The remaining Manning’s n values were consistently 0.04 and 0.05 throughout the model, as used in the existing HEC RAS model. The grouted riprap will be placed below the bridge so that it is protruding from the surface in order to provide for increased roughness.  Flow regime was modeled as subcritical when modeling the 100-yr water surface elevations. Note that the flow becomes supercritical at various points due to the steep grade and drop structures, but FEMA requires the 100-yr floodplain boundary be calculated assuming subcritical flow. A mixed flow regime was used to determine the depth of scour during a 500-yr flood event at the proposed bridge structure.  The downstream boundary condition is the average channel slope of 0.05 feet/feet.  Entrance and loss coefficients are 0.1 and 0.3 at stream cross sections. The Entrance and loss coefficients at the existing South Frontage Road (Section ID’s 402.5 and 402) are 0.3 and 0.5. Entrance and loss coefficients for the new bridge (405.3. and 405.15) are also 0.3 and 0.5. Entrance and loss coefficients at the culverts are 0.5 and 1.0, respectively. 2.4 Proposed Conditions – HEC-RAS Modeling Results Summary The proposed HEC-RAS model was run with the new input data to determine the water surface elevations and velocities along Red Sandstone Creek under the proposed conditions. The HEC-RAS model results indicate that the impacts to the 100-yr water surface elevations are relatively are less than a foot outside of the structures. In addition, the floodplain width decreases in width due to the channelization of Red Sandstone Creek. Table 2 summarizes the results during a 100-yr flow event at key design locations. Note it is important to view this table in conjunction with Exhibit A to see the physical representation of the impacts to the floodplain boundary. The complete tabular results from the HEC-RAS model for the proposed conditions are shown in Exhibit D. HEC-RAS model sections with the 100-yr water surface elevations for the proposed geometry are shown in Exhibit E. The FIS floodplain boundary, the proposed new effective floodplain boundary, and the proposed floodplain boundary are shown in Exhibit A. Proposed vs. new effective ground and 100-yr water surface elevations are shown in Figure 3. Floodplain Modification Permit – Engineering Floodplain Analysis South Frontage Road Bridge at Red Sandstone Creek 11 AMEC Earth & Environmental Table 2. Proposed 100 yr Water Surface Elevations at Key Design Locations (HEC-RAS section ID numbers are in parenthesis). New Effective BFE (100-yr flow) Proposed Conditions (100-yr flow) Location WSE (ft) Velocity (ft/s)WSE (ft) Velocity (ft/s) ~ 200 ft upstream of the I-70 Culvert (407) 8140.04 7.62 8140.04 7.62 32 ft Downstream of the Bridge (404.5, 404.45) 8099.98 6.16 8100.50* 3.15 64 ft Downstream of the Bridge (404.25, 404.24) 8097.96 6.08 8098.52* 8.28 162 ft Downstream of the Bridge (403) 8089.03 6.56 8089.02 6.59 Modeling Boundary – 223 ft Downstream of the Bridge (402) 8085.42 7.71 8085.42 7.71 *Value is interpolated based on the floodplain boundary because the proposed cross sections are perpendicular to the flow, while the existing cross sections are slightly skewed from the perpendicular flow. Cross Section IDs in italics indicated a cross section value in the proposed conditions model. The cross section ID has been given a new value because it crosses the existing cross section, but is slightly skewed from the existing conditions. This was done because the new cross section had to be adjust to run perpendicular to the flow line. Floodplain Modification Permit – Engineering Floodplain Analysis South Frontage Road Bridge at Red Sandstone Creek 12 AMEC Earth & Environmental Profile for the 100-yr Water Surface Elevation: Existing vs. Proposed Conditions 8070 8080 8090 8100 8110 8120 8130 8140 01002003004005006007008009001000 Distance from cross Section ID 406 (located just upstream of the I-70 CMP) El e v a t i o n ( f t ) New Effective Model Minimum Channel Elevation New Effective Model 100-yr WSE Proposed Conditions Minimal Channel Elevation Proposed Conditions 100-yr WSE Figure 2. Proposed vs. Existing Ground Elevations and Water Surface Elevations during a 100-yr Flood Event. 3.0 Conclusions The floodplain analysis evaluated the existing adopted Flood Insurance Study (FIS) floodplain boundary and created a new effective baseline model using more recent and accurate survey data. The new effective baseline model was then used as the baseline model from which to create a new HEC-RAS model to represent the proposed design. This model shows a minimal increase in water surface elevation downstream of the project area. The floodplain narrows just downstream of the new South Frontage Road Bridge, and shortly downstream returns to its existing configuration. The water surface elevation profiles for the proposed conditions match the water surface elevation profiles of the new effective model at cross sections 407 and 402.5. FEMA requires that a Conditional Letter of Map Revision (CLMOR) be submitted for review if the there has been a detailed hydrologic and hydraulic analysis for which the Base (1-percnet-annual-chance) Flood Elevations (BFEs) have been specified. If the project area is within a floodplain boundary, but not designated as a regulatory floodway, then any changes that would result in more than a 1.0-foot increase in the BFE will require a CLMOR. Red Sandstone Creek has a designated floodplain, but is not in a regulatory floodway. Although the increases to the BFE’s downstream of the proposed bridge are less than 1.0 foot, the increases to the BFE’s within the proposed Con/Span arch are greater than 1.0 foot. Therefore, a CLMOR will need to be submitted to FEMA F l o o d p l a i n Mo d i f i c a t i o n Pe r m i t — E n g i n e e r i n g F l o o d p l a i n A n a l y s i s So u t h F r o n t a g e R o a d Br i d g e at R e d S a n d s t o n e C r e e k 14 to ve r i f y t h a t th e p r o p o s e d pr o j e c t m e e t s th e mi n i m u m fl o o d p l a i n m a n a g e m e n t cr i t e r i a of th e Na t i o n a l Fl o o d I n s u r a n c e P r o g r a m (N F I P ) an d , if so , w h a t re v i s i o n s wi l l be m a d e to th e ef f e c t i v e NF I P m a p fo r a co m m u n i t y if th e pr o j e c t is c o m p l e t e d a s p r o p o s e d . 4. 0 E n g i n e e r i n g S t a t e m e n t u n d e r th e di r e c t i o n of : *T h i s P. E . st a m p ap p l i e s to th e fl o o d p l a i n an a l y s i s . It do e s no t ap p l y to th e de s i g n an d co n s t r u c t i o n of th e br i d g e . By : AM E C Ea r t h & E n v i r o n m e n t a l Exhibit A: Plan View of Floodplain Boundaries: existing FEMA, new effective and proposed Exhibit B: HEC-RAS tabular results: New Effective Model Ex h i b i t B . H E C - R A S t a b u l a r r e s u l t s : N e w E f f e c t i v e M o d e l Re a c h R i v e r S t a P r o f i l e Q T o t a l M i n C h E l W . S . E l e v C r i t W . S . E . G . E l e v E . G . S l o p e V e l C h n l F l o w A r e a T o p W i d t h F r o u d e # C h l (c f s ) ( f t ) ( f t ) ( f t ) ( f t ) ( f t / f t ) ( f t / s ) ( s q f t ) ( f t ) Re a c h - 1 4 1 5 . 5 1 0 0 - y e a r 4 9 0 8 2 4 1 . 8 8 2 5 3 . 9 4 8 2 5 3 . 9 7 0 . 0 0 0 0 8 2 1 . 1 8 4 1 4 . 3 6 5 6 . 8 1 0 . 0 8 Re a c h - 1 4 1 5 1 0 0 - y e a r 4 9 0 8 2 4 2 . 8 8 2 5 3 . 9 3 8 2 4 6 . 1 9 8 2 5 3 . 9 6 0 . 0 0 0 2 0 1 1 . 4 3 3 4 3 . 1 7 4 8 . 6 9 0 . 0 9 Re a c h - 1 4 1 4 . 5 C u l v e r t Re a c h - 1 4 1 4 1 0 0 - y e a r 4 9 0 8 2 3 5 . 4 8 2 3 8 . 1 1 8 2 3 8 . 1 1 8 2 3 9 . 2 0 . 0 1 9 7 9 1 8 . 3 7 5 8 . 5 3 2 7 . 3 3 1 . 0 1 Re a c h - 1 4 1 3 . 8 1 0 0 - y e a r 4 9 0 8 2 3 2 . 7 8 2 3 5 . 6 8 2 3 5 . 6 8 2 3 6 . 5 8 0 . 0 3 0 9 8 8 7 . 9 5 6 1 . 6 2 3 1 . 9 6 1 . 0 1 Re a c h - 1 4 1 3 1 0 0 - y e a r 4 9 0 8 2 2 1 . 9 8 2 3 2 . 3 9 8 2 3 2 . 4 1 0 . 0 0 0 0 5 3 0 . 9 4 5 2 0 . 7 3 7 5 . 7 8 0 . 0 6 Re a c h - 1 4 1 2 . 4 1 0 0 - y e a r 4 9 0 8 2 2 1 8 2 3 2 . 3 9 8 2 2 4 . 5 7 8 2 3 2 . 4 0 . 0 0 0 0 6 1 1 4 8 8 . 1 4 7 0 . 8 3 0 . 0 7 Re a c h - 1 4 1 2 . 3 C u l v e r t Re a c h - 1 4 1 2 . 2 1 0 0 - y e a r 4 9 0 8 2 1 2 . 3 8 2 1 5 . 2 8 8 2 1 5 . 2 8 8 2 1 6 . 3 7 0 . 0 3 1 5 2 8 . 3 8 5 8 . 4 7 2 7 . 2 2 1 . 0 1 Re a c h - 1 4 1 2 1 0 0 - y e a r 4 9 0 8 2 1 1 . 4 8 2 1 4 . 1 9 8 2 1 4 . 1 9 8 2 1 5 . 1 3 0 . 0 1 9 6 1 8 7 . 7 9 6 2 . 8 8 3 3 . 8 9 1 . 0 1 Re a c h - 1 4 1 1 1 0 0 - y e a r 4 9 0 8 2 0 0 8 2 0 1 . 9 6 8 2 0 1 . 9 6 8 2 0 2 . 7 5 0 . 0 2 0 6 7 4 7 . 1 4 6 8 . 6 6 4 3 . 7 9 1 Re a c h - 1 4 1 0 . 5 1 0 0 - y e a r 4 9 0 8 1 8 8 . 8 8 1 9 2 . 1 2 8 1 9 2 . 1 2 8 1 9 3 . 4 0 . 0 2 0 0 7 5 9 . 0 9 5 3 . 9 1 2 1 . 0 9 1 Re a c h - 1 4 1 0 1 0 0 - y e a r 4 9 0 8 1 8 6 . 4 8 1 8 9 . 5 9 8 1 8 9 . 1 4 8 1 9 0 . 2 9 0 . 0 1 1 5 8 9 6 . 6 9 7 3 . 2 3 2 9 . 4 1 0 . 7 5 Re a c h - 1 4 0 9 . 5 B r i d g e Re a c h - 1 4 0 9 . 3 1 0 0 - y e a r 4 9 0 8 1 8 4 8 1 8 7 . 4 2 8 1 8 7 . 4 2 8 1 8 8 . 5 5 0 . 0 2 0 1 1 1 8 . 5 4 5 7 . 3 7 2 5 . 7 7 1 . 0 1 Re a c h - 1 4 0 9 . 2 1 0 0 - y e a r 4 9 0 8 1 7 6 . 1 8 1 8 2 . 6 1 8 1 8 3 . 7 1 0 . 0 1 4 5 1 9 8 . 4 1 5 8 . 2 9 1 7 . 9 1 0 . 8 2 Re a c h - 1 4 0 9 1 0 0 - y e a r 4 9 0 8 1 7 9 8 1 8 1 . 2 2 8 1 8 1 . 2 2 8 1 8 2 . 0 7 0 . 0 2 0 1 7 2 7 . 4 1 6 6 . 1 3 3 9 . 1 9 1 . 0 1 Re a c h - 1 4 0 8 1 0 0 - y e a r 4 9 0 8 1 5 6 8 1 5 8 . 0 2 8 1 5 8 . 0 2 8 1 5 8 . 9 3 0 . 0 2 0 0 5 7 7 . 6 6 6 4 3 5 . 4 3 1 Re a c h - 1 4 0 7 1 0 0 - y e a r 4 9 0 8 1 3 8 8 1 4 0 . 0 4 8 1 4 0 . 0 4 8 1 4 0 . 9 5 0 . 0 1 9 9 3 6 7 . 6 2 6 4 . 3 3 5 . 8 1 Re a c h - 1 4 0 6 . 5 1 0 0 - y e a r 4 9 0 8 1 2 5 . 5 5 8 1 3 5 . 0 3 8 1 3 5 . 0 7 0 . 0 0 0 1 6 9 1 . 4 8 3 5 1 . 5 9 4 . 1 6 0 . 1 1 Re a c h - 1 4 0 6 1 0 0 - y e a r 4 9 0 8 1 2 4 . 2 3 8 1 3 5 . 0 2 8 1 2 7 . 7 9 8 1 3 5 . 0 6 0 . 0 0 0 2 4 6 1 . 7 3 3 3 5 . 5 1 0 2 . 3 2 0 . 1 2 Re a c h - 1 4 0 5 . 7 C u l v e r t Re a c h - 1 4 0 5 . 5 1 0 0 - y e a r 4 9 0 8 1 0 5 . 6 1 8 1 1 0 8 1 1 0 8 1 1 1 . 5 6 0 . 0 2 1 6 7 1 0 . 0 2 4 8 . 8 8 1 5 . 9 1 1 . 0 1 Re a c h - 1 4 0 5 . 3 1 0 0 - y e a r 4 9 0 8 1 0 4 . 1 8 8 1 0 8 . 8 2 8 1 0 8 . 8 2 8 1 0 9 . 9 3 0 . 0 2 0 1 7 4 8 . 4 5 5 7 . 9 6 2 6 . 8 2 1 . 0 1 Re a c h - 1 4 0 5 . 2 5 1 0 0 - y e a r 4 9 0 8 1 0 4 8 1 0 7 . 6 2 8 1 0 7 . 7 7 0 . 0 0 3 8 6 4 3 . 1 1 5 8 . 1 5 1 0 0 . 0 6 0 . 4 3 Re a c h - 1 4 0 5 1 0 0 - y e a r 4 9 0 8 1 0 4 8 1 0 6 . 7 7 8 1 0 6 . 7 7 8 1 0 7 . 3 1 0 . 0 2 3 3 7 5 5 . 9 8 2 . 9 8 7 7 . 1 2 1 Re a c h - 1 4 0 4 . 5 1 0 0 - y e a r 4 9 0 8 0 9 6 . 4 3 8 0 9 9 . 9 8 8 0 9 9 . 9 8 8 1 0 0 . 5 7 0 . 0 2 4 0 2 8 6 . 1 6 7 9 . 6 7 0 . 0 6 1 . 0 2 Re a c h - 1 4 0 4 . 2 5 1 0 0 - y e a r 4 9 0 8 0 9 6 . 0 2 8 0 9 7 . 9 6 8 0 9 7 . 9 6 8 0 9 8 . 5 3 0 . 0 2 3 2 4 6 6 . 0 8 8 0 . 6 3 7 1 . 5 9 1 . 0 1 Re a c h - 1 4 0 4 1 0 0 - y e a r 4 9 0 8 0 9 2 . 9 6 8 0 9 6 . 3 5 8 0 9 6 . 3 5 8 0 9 7 . 2 6 0 . 0 2 2 3 7 . 6 8 6 3 . 7 9 3 5 . 5 5 1 . 0 1 Re a c h - 1 4 0 3 1 0 0 - y e a r 4 9 0 8 0 8 5 . 4 1 8 0 8 9 . 0 3 8 0 8 9 . 7 0 . 0 1 0 9 5 5 6 . 5 6 7 4 . 6 6 3 3 . 0 3 0 . 7 7 Re a c h - 1 4 0 2 . 5 1 0 0 - y e a r 4 9 0 8 0 8 5 . 2 1 8 0 8 9 . 0 6 8 0 8 7 . 5 3 8 0 8 9 . 4 1 0 . 0 0 3 9 5 8 4 . 7 6 1 0 2 . 8 3 2 8 . 5 9 0 . 4 4 Re a c h - 1 4 0 2 . 3 B r i d g e Re a c h - 1 4 0 2 1 0 0 - y e a r 4 9 0 8 0 8 2 . 3 9 8 0 8 5 . 4 2 8 0 8 5 . 4 2 8 0 8 6 . 3 5 0 . 0 2 0 0 2 9 7 . 7 1 6 3 . 5 4 3 4 . 5 1 Re a c h - 1 4 0 1 . 5 1 0 0 - y e a r 4 9 0 8 0 7 9 . 8 5 8 0 8 3 . 1 6 8 0 8 3 . 1 6 8 0 8 4 . 0 4 0 . 0 1 9 8 1 9 7 . 5 5 6 4 . 8 8 3 6 . 7 6 1 Re a c h - 1 4 0 1 1 0 0 - y e a r 4 9 0 8 0 7 3 . 1 3 8 0 7 5 . 9 6 8 0 7 5 . 9 6 8 0 7 6 . 5 7 0 . 0 2 2 2 8 1 6 . 2 6 7 8 . 2 8 6 4 . 8 2 1 1 of 1 Exhibit C: South Frontage Road Bridge Hydraulic Design Drawings Exhibit D: HEC-RAS tabular results: Proposed Conditions E x h i b i t D : H E C - R A S T a b u l a r R e s u l t s : P r o p o s e d C o n d i t i o n s Re a c h R i v e r S t a P r o f i l e Q T o t a l M i n C h E l W . S . E l e v C r i t W . S . E . G . E l e v E . G . S l o p e V e l C h n l F l o w A r e a T o p W i d t h F r o u d e # C h l (c f s ) ( f t ) ( f t ) ( f t ) ( f t ) ( f t / f t ) ( f t / s ) ( s q f t ) ( f t ) 1 4 1 5 . 5 1 0 0 y r 4 9 0 8 2 4 1 . 8 8 2 5 3 . 9 4 8 2 5 3 . 9 6 0 . 0 0 0 0 8 2 1 . 1 8 4 1 4 . 3 1 5 6 . 8 0 . 0 8 1 4 1 5 1 0 0 y r 4 9 0 8 2 4 2 . 8 8 2 5 3 . 9 3 8 2 4 6 . 1 9 8 2 5 3 . 9 6 0 . 0 0 0 1 2 9 1 . 4 3 3 4 3 . 1 7 4 8 . 6 9 0 . 0 9 1 4 1 4 . 5 C u l v e r t 1 4 1 4 1 0 0 y r 4 9 0 8 2 3 5 . 4 8 2 3 8 . 1 1 8 2 3 8 . 1 1 8 2 3 9 . 2 0 . 0 1 9 7 9 1 8 . 3 7 5 8 . 5 3 2 7 . 3 3 1 . 0 1 1 4 1 3 . 8 1 0 0 y r 4 9 0 8 2 3 2 . 7 8 2 3 5 . 6 8 2 3 5 . 6 8 2 3 6 . 5 8 0 . 0 1 9 8 3 2 7 . 9 5 6 1 . 6 2 3 1 . 9 6 1 . 0 1 1 4 1 3 1 0 0 y r 4 9 0 8 2 2 1 . 9 8 2 3 2 . 3 9 8 2 3 2 . 4 1 0 . 0 0 0 0 5 3 0 . 9 4 5 2 0 . 7 3 7 5 . 7 8 0 . 0 6 1 4 1 2 . 4 1 0 0 y r 4 9 0 8 2 2 1 8 2 3 2 . 3 9 8 2 2 4 . 5 7 8 2 3 2 . 4 0 . 0 0 0 0 6 1 1 4 8 8 . 1 4 7 0 . 8 3 0 . 0 7 1 4 1 2 . 3 C u l v e r t 1 4 1 2 . 2 1 0 0 y r 4 9 0 8 2 1 2 . 3 8 2 1 5 . 2 8 8 2 1 5 . 2 8 8 2 1 6 . 3 7 0 . 0 2 0 1 7 3 8 . 3 8 5 8 . 4 7 2 7 . 2 2 1 . 0 1 1 4 1 2 1 0 0 y r 4 9 0 8 2 1 1 . 4 8 2 1 4 . 1 9 8 2 1 4 . 1 9 8 2 1 5 . 1 3 0 . 0 1 9 6 1 8 7 . 7 9 6 2 . 8 8 3 3 . 8 9 1 . 0 1 1 4 1 1 1 0 0 y r 4 9 0 8 2 0 0 8 2 0 1 . 9 6 8 2 0 1 . 9 6 8 2 0 2 . 7 5 0 . 0 2 0 6 7 4 7 . 1 4 6 8 . 6 6 4 3 . 7 9 1 1 4 1 0 . 5 1 0 0 y r 4 9 0 8 1 8 8 . 8 8 1 9 2 . 1 2 8 1 9 2 . 1 2 8 1 9 3 . 4 0 . 0 2 0 0 7 5 9 . 0 9 5 3 . 9 1 2 1 . 0 9 1 1 4 1 0 1 0 0 y r 4 9 0 8 1 8 6 . 4 8 1 8 9 . 5 9 8 1 8 9 . 1 4 8 1 9 0 . 2 9 0 . 0 1 1 5 8 9 6 . 6 9 7 3 . 2 3 2 9 . 4 1 0 . 7 5 1 4 0 9 . 5 B r i d g e 1 4 0 9 . 3 1 0 0 y r 4 9 0 8 1 8 4 8 1 8 7 . 4 2 8 1 8 7 . 4 2 8 1 8 8 . 5 5 0 . 0 2 0 1 1 1 8 . 5 4 5 7 . 3 7 2 5 . 7 7 1 . 0 1 1 4 0 9 . 2 1 0 0 y r 4 9 0 8 1 7 6 . 1 8 1 8 2 . 6 1 8 1 8 3 . 7 1 0 . 0 1 4 5 2 5 8 . 4 1 5 8 . 2 8 1 7 . 9 1 0 . 8 2 1 4 0 9 1 0 0 y r 4 9 0 8 1 7 9 8 1 8 1 . 2 2 8 1 8 1 . 2 2 8 1 8 2 . 0 7 0 . 0 2 0 1 7 2 7 . 4 1 6 6 . 1 3 3 9 . 1 9 1 . 0 1 1 4 0 8 1 0 0 y r 4 9 0 8 1 5 6 8 1 5 8 . 0 2 8 1 5 8 . 0 2 8 1 5 8 . 9 3 0 . 0 1 9 9 0 8 7 . 6 4 6 4 . 1 6 3 5 . 4 4 1 1 4 0 7 1 0 0 y r 4 9 0 8 1 3 8 8 1 4 0 . 0 4 8 1 4 0 . 0 4 8 1 4 0 . 9 5 0 . 0 2 0 0 6 8 7 . 6 4 6 4 . 1 6 3 5 . 7 9 1 . 0 1 1 4 0 6 . 5 1 0 0 y r 4 9 0 8 1 2 5 . 5 5 8 1 3 5 . 0 3 8 1 3 5 . 0 6 0 . 0 0 0 1 6 9 1 . 4 9 3 5 1 . 2 3 9 4 . 1 5 0 . 1 1 1 4 0 6 1 0 0 y r 4 9 0 8 1 2 4 . 2 3 8 1 3 5 . 0 2 8 1 2 7 . 7 7 8 1 3 5 . 0 6 0 . 0 0 0 2 4 5 1 . 7 3 3 3 5 . 2 1 0 2 . 3 0 . 1 2 1 4 0 5 . 9 9 C u l v e r t 1 4 0 5 . 9 1 0 0 y r 4 9 0 8 1 0 7 8 1 0 9 . 2 2 8 1 0 9 . 2 2 8 1 1 0 . 1 9 0 . 0 1 1 4 5 2 7 . 9 6 2 . 0 4 3 2 . 3 1 1 4 0 5 . 8 1 0 0 y r 4 9 0 8 1 0 4 8 1 0 9 . 5 9 8 1 0 9 . 7 0 . 0 0 0 4 2 2 2 . 6 5 1 8 5 . 2 1 4 0 . 8 8 0 . 2 2 1 4 0 5 . 7 1 0 0 y r 4 9 0 8 1 0 4 8 1 0 9 . 5 9 8 1 0 9 . 6 8 0 . 0 0 0 3 2 9 2 . 4 8 1 9 9 . 5 5 4 0 . 8 8 0 . 2 1 4 0 5 . 6 1 0 0 y r 4 9 0 8 1 0 6 . 8 9 8 1 0 9 . 2 8 1 0 9 . 6 5 0 . 0 0 4 1 2 7 5 . 3 5 9 2 . 3 4 4 0 . 8 8 0 . 6 3 1 4 0 5 . 4 1 0 0 y r 4 9 0 8 1 0 7 8 1 0 8 . 7 2 8 1 0 8 . 7 2 8 1 0 9 . 5 5 0 . 0 1 1 7 2 3 7 . 3 3 6 7 . 0 3 4 0 . 8 8 1 . 0 1 1 4 0 5 . 3 1 0 0 y r 4 9 0 8 1 0 5 . 9 9 8 1 0 8 . 3 8 1 0 8 . 1 4 8 1 0 8 . 9 8 0 . 0 0 8 8 9 2 6 . 6 1 7 4 . 1 2 4 2 0 . 8 8 1 4 0 5 . 2 8 B r i d g e 1 4 0 5 . 1 5 1 0 0 y r 4 9 0 8 0 9 9 . 1 2 8 1 0 1 . 5 6 8 1 0 1 . 5 6 8 1 0 2 . 3 9 0 . 0 2 0 7 9 2 7 . 3 2 6 6 . 9 7 4 1 . 0 7 1 . 0 1 1 4 0 5 . 1 1 0 0 y r 4 9 0 8 0 9 8 . 7 6 8 1 0 1 . 4 9 8 1 0 2 . 0 4 0 . 0 1 0 8 5 3 5 . 9 7 8 3 . 8 1 4 8 . 1 6 0 . 7 6 1 4 0 5 . 0 5 1 0 0 y r 4 9 0 8 0 9 7 . 6 8 8 1 0 1 . 6 9 8 1 0 1 . 9 3 0 . 0 0 2 9 6 3 . 9 9 1 3 0 . 7 6 5 8 0 . 4 2 1 4 0 5 1 0 0 y r 4 9 0 8 0 9 6 . 4 8 8 1 0 1 . 7 6 8 1 0 1 . 8 9 0 . 0 0 1 0 5 9 2 . 9 1 8 2 . 1 6 0 . 3 5 0 . 2 6 1 4 0 4 . 9 5 1 0 0 y r 4 9 0 8 0 9 6 8 1 0 1 . 7 8 8 1 0 1 . 8 7 0 . 0 0 0 6 1 7 2 . 4 9 2 1 6 6 3 . 4 4 0 . 2 1 1 4 0 4 . 9 1 0 0 y r 4 9 0 8 0 9 6 8 1 0 1 . 7 9 8 1 0 1 . 8 7 0 . 0 0 0 4 9 3 2 . 3 1 2 3 2 . 4 6 6 5 . 6 6 0 . 1 9 1 of 2 E x h i b i t D : H E C - R A S T a b u l a r R e s u l t s : P r o p o s e d C o n d i t i o n s 1 4 0 4 . 8 5 1 0 0 y r 4 9 0 8 0 9 6 8 1 0 1 . 7 8 8 1 0 1 . 8 6 0 . 0 0 0 5 1 4 2 . 3 3 2 2 4 . 7 7 6 2 . 3 1 0 . 1 9 1 4 0 4 . 7 1 0 0 y r 4 9 0 8 0 9 6 8 1 0 1 . 7 8 1 0 1 . 8 5 0 . 0 0 1 1 8 4 3 . 1 5 1 7 1 . 8 9 5 7 . 2 3 0 . 2 7 1 4 0 4 . 4 5 1 0 0 y r 4 9 0 8 0 9 8 . 0 2 8 1 0 1 . 4 8 8 1 0 1 . 8 3 0 . 0 0 4 2 9 1 4 . 9 3 1 1 3 . 8 8 5 2 . 5 3 0 . 5 1 1 4 0 4 . 4 1 0 0 y r 4 9 0 8 0 9 8 . 0 2 8 1 0 0 . 8 6 8 1 0 0 . 8 6 8 1 0 1 . 7 4 0 . 0 1 5 8 7 8 7 . 8 6 7 0 . 2 4 4 1 . 8 0 . 9 4 1 4 0 4 . 3 1 0 0 y r 4 9 0 8 0 9 6 . 8 1 8 1 0 0 . 1 1 8 1 0 0 . 1 1 8 1 0 1 . 1 2 0 . 0 1 4 2 6 8 8 . 4 7 6 7 . 6 2 3 5 . 9 8 0 . 9 1 1 4 0 4 . 2 4 1 0 0 y r 4 9 0 8 0 9 5 . 7 7 8 0 9 8 . 8 7 8 0 9 8 . 8 7 8 0 9 9 . 8 9 0 . 0 1 5 3 4 4 8 . 2 8 6 4 . 8 9 3 5 . 8 0 . 9 3 1 4 0 4 . 2 1 0 0 y r 4 9 0 8 0 9 5 . 1 1 8 0 9 8 . 3 1 8 0 9 8 . 3 1 8 0 9 9 . 3 2 0 . 0 1 5 4 1 5 8 . 2 1 6 5 . 1 3 3 7 . 2 6 0 . 9 2 1 4 0 4 . 1 2 1 0 0 y r 4 9 0 8 0 9 3 . 6 8 0 9 7 . 2 4 8 0 9 7 . 2 4 8 0 9 8 . 3 8 0 . 0 1 9 0 2 9 8 . 6 5 7 . 1 7 2 7 . 1 3 1 1 4 0 3 . 9 9 1 0 0 y r 4 9 0 8 0 9 2 . 3 4 8 0 9 6 . 2 6 8 0 9 6 . 2 6 8 0 9 7 . 5 5 0 . 0 1 9 4 8 8 9 . 1 1 5 3 . 7 8 2 1 . 2 1 . 0 1 1 4 0 3 . 9 5 1 0 0 y r 4 9 0 8 0 9 1 . 2 7 8 0 9 5 . 3 5 8 0 9 5 . 3 5 8 0 9 6 . 5 9 0 . 0 1 8 4 3 7 8 . 9 5 5 5 . 4 4 2 3 . 8 9 0 . 9 9 1 4 0 3 . 8 1 0 0 y r 4 9 0 8 0 9 0 . 3 9 8 0 9 4 . 0 9 8 0 9 4 . 0 9 8 0 9 5 . 2 0 . 0 1 9 5 2 8 8 . 4 3 5 8 . 1 2 2 6 . 9 1 . 0 1 1 4 0 3 . 7 9 1 0 0 y r 4 9 0 8 0 8 8 . 8 4 8 0 9 2 . 9 3 8 0 9 2 . 9 3 8 0 9 4 . 1 9 0 . 0 1 9 3 9 1 9 . 0 3 5 4 . 2 7 2 1 . 7 6 1 . 0 1 1 4 0 3 . 7 8 1 0 0 y r 4 9 0 8 0 8 7 . 4 8 8 0 9 1 . 6 4 8 0 9 1 . 6 4 8 0 9 2 . 9 6 0 . 0 1 9 8 0 1 9 . 2 5 3 . 2 4 2 0 . 5 4 1 . 0 1 1 4 0 3 1 0 0 y r 4 9 0 8 0 8 5 . 4 1 8 0 8 9 . 0 2 8 0 8 9 . 7 0 . 0 1 1 0 7 8 6 . 5 9 7 4 . 3 7 3 2 . 9 9 0 . 7 7 1 4 0 2 . 5 1 0 0 y r 4 9 0 8 0 8 5 . 2 1 8 0 8 9 . 0 5 8 0 8 7 . 5 3 8 0 8 9 . 4 1 0 . 0 0 3 9 8 8 4 . 7 8 1 0 2 . 5 8 2 8 . 5 9 0 . 4 4 1 4 0 2 . 3 B r i d g e 1 4 0 2 1 0 0 y r 4 9 0 8 0 8 2 . 3 9 8 0 8 5 . 4 2 8 0 8 5 . 4 2 8 0 8 6 . 3 5 0 . 0 2 0 0 2 9 7 . 7 1 6 3 . 5 4 3 4 . 5 1 1 4 0 1 . 2 5 1 0 0 y r 4 9 0 8 0 7 9 . 8 5 8 0 8 3 . 1 6 8 0 8 3 . 1 6 8 0 8 4 . 0 4 0 . 0 1 9 8 1 9 7 . 5 5 6 4 . 8 8 3 6 . 7 6 1 1 4 0 1 1 0 0 y r 4 9 0 8 0 7 3 . 1 3 8 0 7 5 . 9 6 8 0 7 5 . 9 6 8 0 7 6 . 5 7 0 . 0 2 2 2 2 7 6 . 2 5 7 8 . 3 4 6 4 . 8 4 1 2 of 2 Exhibit E: HEC-RAS Cross Sections: Proposed Conditions 1 of 19 0 20 40 60 80 100 120 140 160 1808124 8126 8128 8130 8132 8134 8136 8138 8140 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 406 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 1. HEC-RAS Cross Section ID 406 0 20 40 60 80 100 120 140 160 1808124 8126 8128 8130 8132 8134 8136 8138 8140 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 2. HEC-RAS Cross Section ID 405.99 Up 2 of 19 0 10 20 30 40 508105 8110 8115 8120 8125 8130 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .03 .03 .03 Figure 3. HEC-RAS Cross Section ID 405.99 down 0 10 20 30 40 508107.0 8107.5 8108.0 8108.5 8109.0 8109.5 8110.0 8110.5 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 405.9: Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .03 .03 .03 Figure 4. HEC-RAS Cross Section ID 405.9 3 of 19 0 10 20 30 40 508104 8105 8106 8107 8108 8109 8110 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .03 . 03 Figure 5. HEC-RAS Cross Section ID 405.8 0 10 20 30 40 508104 8105 8106 8107 8108 8109 8110 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .03 .03 Figure 6. HEC-RAS Cross Section ID 405.7 4 of 19 0 10 20 30 40 508106.5 8107.0 8107.5 8108.0 8108.5 8109.0 8109.5 8110.0 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta . 03 .03 Figure 7. HEC-RAS Cross Section ID 405.6 0 10 20 30 40 508107.0 8107.5 8108.0 8108.5 8109.0 8109.5 8110.0 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .0 3 .03 Figure 8. HEC-RAS Cross Section ID 405.4 5 of 19 0 10 20 30 40 508105.5 8106.0 8106.5 8107.0 8107.5 8108.0 8108.5 8109.0 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 405.3: ACAD 625 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .03 Figure 9. HEC-RAS Cross Section ID 405.3 0 10 20 30 40 508104 8106 8108 8110 8112 8114 8116 8118 8120 8122 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .03 Figure 10. . HEC-RAS Cross Section ID 405.28 Up 6 of 19 0 10 20 30 40 508095 8100 8105 8110 8115 8120 8125 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta . 05 .04 Figure 11. HEC-RAS Cross Section ID 405.28 0 10 20 30 40 508099.0 8099.5 8100.0 8100.5 8101.0 8101.5 8102.0 8102.5 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 405.15: ACAD 575 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .0 5 .04 Figure 12. HEC-RAS Cross Section ID 405.15 7 of 19 0 10 20 30 40 50 60 708098.5 8099.0 8099.5 8100.0 8100.5 8101.0 8101.5 8102.0 8102.5 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 405.1: ACAD 573 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 13. HEC-RAS Cross Section ID 405.1 0 10 20 30 40 50 60 70 808096 8098 8100 8102 8104 8106 8108 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 405.05: ACAD 570 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 14. HEC-RAS Cross Section ID 405.05 8 of 19 0 10 20 30 40 50 60 70 808096 8098 8100 8102 8104 8106 8108 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 405: ACAD 566 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 15. HEC-RAS Cross Section ID 405 0 20 40 60 80 100 120 140 160 1808095 8100 8105 8110 8115 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 404.95: ACAD 563 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 16. HEC-RAS Cross Section ID 404.95 9 of 19 0 20 40 60 80 100 120 140 160 1808095 8100 8105 8110 8115 8120 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 404.9: ACAD 560 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 17. HEC-RAS Cross Section ID 404.9 0 20 40 60 80 100 120 140 1608096 8098 8100 8102 8104 8106 8108 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 404.85: ACAD 552 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 18. HEC-RAS Cross Section ID 404.85 10 of 19 0 10 20 30 40 50 60 708096 8098 8100 8102 8104 8106 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 404.5: ACAD 545 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 19. HEC-RAS Cross Section ID 404.7 0 20 40 60 80 100 120 1408098 8100 8102 8104 8106 8108 8110 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 404.45: ACAD 542 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 20. HEC-RAS Cross Section ID 404.45 11 of 19 0 20 40 60 80 100 120 1408098 8100 8102 8104 8106 8108 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 404.4: ACAD 538 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 21. HEC-RAS Cross Section ID 404.4 0 20 40 60 80 100 120 1408096 8098 8100 8102 8104 8106 8108 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 404.3: ACAD 524 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 22. HEC-RAS Cross Section ID 404.3 12 of 19 0 20 40 60 80 100 120 1408094 8096 8098 8100 8102 8104 8106 8108 8110 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 404.25: ACAD 511 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 23. HEC-RAS Cross Section ID 404.24 0 20 40 60 80 100 1208094 8096 8098 8100 8102 8104 8106 8108 8110 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 404.2: ACAD 499 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 24. HEC-RAS Cross Section ID 404.2 13 of 19 0 20 40 60 80 100 1208092 8094 8096 8098 8100 8102 8104 8106 8108 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 404.12: ACAD 86 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 25. HEC-RAS Cross Section ID 404.12 0 20 40 60 80 1008092 8094 8096 8098 8100 8102 8104 8106 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 403.99: ACAD 467 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 26. HEC-RAS Cross Section ID 403.99 14 of 19 0 20 40 60 808090 8092 8094 8096 8098 8100 8102 8104 8106 8108 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 403.95: ACAD 451 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 27. HEC-RAS Cross Section ID 403.95 0 10 20 30 40 50 60 708090 8092 8094 8096 8098 8100 8102 8104 8106 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 403.8: ACAD 438 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 Figure 28. HEC-RAS Cross Section ID 403.8 15 of 19 0 10 20 30 40 50 608088 8090 8092 8094 8096 8098 8100 8102 8104 8106 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 403.79: ACAD 407 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 . 05 Figure 29. HEC-RAS Cross Section ID 403.79 0 10 20 30 40 50 608086 8088 8090 8092 8094 8096 8098 8100 8102 8104 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 403.78: ACAD 386 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 30. HEC-RAS Cross Section ID 403.78 16 of 19 0 50 100 150 2008085 8090 8095 8100 8105 8110 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 403 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 31. HEC-RAS Cross Section ID 403 0 50 100 150 200 2508085 8090 8095 8100 8105 8110 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 402.5 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 32. HEC-RAS Cross Section ID 402.5 17 of 19 0 50 100 150 200 2508085 8090 8095 8100 8105 8110 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 33. HEC-RAS Cross Section ID 402.3 Up 0 20 40 60 80 100 120 140 1608080 8085 8090 8095 8100 8105 8110 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 34. HEC-RAS Cross Section ID 402.3 Down 18 of 19 0 20 40 60 80 100 120 140 1608080 8085 8090 8095 8100 8105 8110 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 402 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 35. HEC-RAS Cross Section ID 402 0 20 40 60 80 100 120 140 160 1808075 8080 8085 8090 8095 8100 8105 8110 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 401.25 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 36. HEC-RAS Cross Section ID 401.25 19 of 19 0 50 100 150 2008070 8075 8080 8085 8090 8095 8100 8105 RSC_Bridge Proposed Plan: Plan 04 10/25/2010 401 Station (ft) El e v a t i o n ( f t ) Legend EG 100 yr WS 100 yr Ground Bank Sta .05 .04 .05 Figure 37. HEC-RAS Cross Section ID 401 Attachment A: Existing FEMA floodplain boundary as produced by J.F. Sato and Associates Attachment B: Peak Land Consultants Survey, October 8, 2008