Risk analysis: Sacramento levees

<body topmargin=0 leftmargin=0 marginheight=0 marginwidth=0> <table cellpadding=0 cellspacing=0 border=0><tr> <td valign="top" rowspan="2" width=185 BGCOLOR="#FFFFFF" TEXT="#080000"> <div> <A HREF="index.htm" TARGET="_top" TITLE="David Ford Consulting Engineers"><U><B><IMG SRC="0d058960.png" border=0 width="88" height="150" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></U></A></div> <bR> <div>    <FONT SIZE="1" COLOR="#000000" FACE="Verdana" > </FONT></div> <div> <B> <TABLE BORDER="0" CELLPADDING="4" CELLSPACING="1" WIDTH="156" BORDERCOLORLIGHT="#FFFFFF" BORDERCOLORDARK="#FFFFFF" FRAME="VOID" RULES="NONE" HSPACE="0" VSPACE="0" > <tR> <tD VALIGN=TOP HEIGHT= 27 WIDTH="146"><div> David Ford Consulting Engineers, Inc.</div> </tD> </tR> <tR> <tD VALIGN=TOP HEIGHT= 27 ><NOBR><div> 2015 J Street, Suite 200</div> <div> Sacramento, CA 95811</div> </NOBR></tD> </tR> <tR> <tD VALIGN=TOP HEIGHT= 27 WIDTH="146"><div> tel: 916.447.8779</div> <div> fax: 916.447.8780</div> </tD> </tR> <tR> <tD VALIGN=TOP HEIGHT= 27 WIDTH="146"><div> <A HREF="mailto:support@ford-consulting.com" TARGET="_top" TITLE="mailto:support@ford-consulting.com"><U>support@ford-consulting.com</U></A></div> </tD> </tR> </TABLE></B></div> <div>    </div> <bR> <div> <A HREF="index.htm" TARGET="_top" TITLE="David Ford Consulting Engineers"><U>Home</U></A></div> <div> <A HREF="id461.htm" TARGET="_top" TITLE="About us"><U>About us</U></A></div> <div> <A HREF="news.htm" TARGET="_top" TITLE="News"><U>News</U></A></div> <div> <A HREF="hydrologic_engineering.htm" TARGET="_top" TITLE="Hydrologic engineering"><U>Hydrologic engineering</U></A></div> <div> <A HREF="water_resource_planning.htm" TARGET="_top" TITLE="Water resource planning"><U>Water resource planning</U></A></div> <div> <A HREF="flood_economic_and_risk_analyses.htm" TARGET="_top" TITLE="Flood economic and risk analyses"><U>Flood economic/risk analyses</U></A></div> <div> <A HREF="flood_warning.htm" TARGET="_top" TITLE="Flood warning"><U>Flood warning</U></A></div> <div> <A HREF="decision_support_system_development.htm" TARGET="_top" TITLE="Decision support system development"><U>Decision support systems</U></A></div> <bR> </td> <td valign="top" colspan=2 height=40 BGCOLOR="#3366CC" TEXT="#080000" bgproperties="fixed" background="14400980ezthpx.png"> <div> <B>Risk analysis: Sacramento levees</B></div> <div> </div> </td> </tr><tr> <td valign="top" height=440 colspan=2 BGCOLOR="#FFFFFF" TEXT="#080000" bgproperties="fixed" background="06c00962egerdp.png"> <div> <TABLE BORDER="0" CELLPADDING="2" CELLSPACING="1" WIDTH="547" BORDERCOLORLIGHT="#C0C0C0" BORDERCOLORDARK="#808080" FRAME="BOX" RULES="ALL" HSPACE="0" VSPACE="0" > <tR> <tD VALIGN=TOP COLSPAN=3 BGCOLOR=#CC0000 HEIGHT= 16 WIDTH="537"><div> <B>Situation</B></div> </tD> </tR> <tR> <tD VALIGN=TOP COLSPAN=3 HEIGHT= 427 WIDTH="537"><bR> <div> <B><IMG SRC="157a1140.jpg" border=0 width="417" height="276" ALT="Flooding in north Sacramento" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></div> <div> <I>North area flooding (Courtesy of Sacramento Area Flood Control Agency)</I></div> <div> The Sacramento Area Flood Control Agency (SAFCA) planned to increase flood protection by raising, strengthening, and lengthening a levee along Dry / Robla Creeks. This levee would protect approximately 2000 residential and commercial structures. However, raising the levee might raise water surfaces between the levees upstream of the protected area, and this might induce damage to approximately 150 structures. SAFCA asked us to assess the impact.</div> </tD> </tR> <tR> <tD VALIGN=TOP COLSPAN=3 BGCOLOR=#339933 HEIGHT= 16 WIDTH="537"><div> <B>Action</B></div> </tD> </tR> <tR> <tD VALIGN=TOP COLSPAN=3 HEIGHT= 172 WIDTH="537"><div> We conducted a floodplain structure inventory, developed a relational database, integrated hydrological and hydraulic information, and used the <A HREF="corps__manual_on_risk_based_analysis.htm" TARGET="_top" TITLE="Corps manual on riskbased analysis"><U>Corps' risk and uncertainty (R&U) procedures</U></A> to compute the expected annual damage (EAD) and the annual exceedence probability (AEP) for the structures. We prepared a technical report, briefed SAFCA staff and SAFCA Board members, met with affected property owners, and participated in preparation of the Environmental Impact Report (EIR) that is necessary to meet California Environmental Quality Act (CEQA) requirements. </div> <div> Subsequently, for the County of Sacramento, we conducted a companion study to assess the EAD and AEP of the 2000 protected structures.</div> </tD> </tR> </TABLE></div> <bR> </td> </tr></table></body>