SLIDE 1 Mitigation Assessment Team Report on Midwest Floods of 2008In Iowa and Wisconsin SLIDE 2 Iowa Rivers and MAT Visits Cedar River (and its tributaries) – Clarksville, Waverly, Shell Rock, New Hartford, Cedar Falls, Waterloo, La Porte City, Vinton, Palo, Cedar Rapids Wapsipinicon River – Independence (HMGP acquisitions) Iowa River – Coralville, Iowa City, Columbus Junction (where Cedar and Iowa rivers join), and Oakville SLIDE 3 Wisconsin Rivers and MAT Visits Map showing the river names and location of the site visits SLIDE 4 Cedar Rapids Flood Zones and Actual Inundation This slide contains animation. Each zone listed below will be added to the base map upon mouse click. Blue = 100-year Floodplain, Pink = 500-year Floodplain, Purple = Actual Observed Inundation Mays Island - The Cedar Rapids City Hall and the Linn County Courthouse were built in 1927. An underground parking structure connects the two buildings and the Linn County Detention Center via underground access tunnels. SLIDE 5 Cedar Rapids, Iowa Photo of Cedar Rapids city street flooded Map showing flood zones in Cedar Rapids Power at the Reedsburg Sewer Pump Station was lost Emergency generator could not be run because natural gas had been shut off by the city as part of its emergency procedures Pump station’s wet well and portions of the sewer collection system backed up and became surcharged. This event resulted in sewer backups in homes, commercial buildings, and public facilities. SLIDE 6 Cedar Rapids, Iowa Map showing o.2 percent annual chance of flood and areas of inundation beyond and in addition to mapped flood zones. Photo of flooded Commercial property on the edge of 0.2-percent-annual-chance floodplain (500-year) SLIDE 7 Cedar Rapids, Iowa Map showing 1-percent annual chance of flood and 0.2 percent annual chance of flood Two photos showing residential areas ‘protected’ by levees SLIDE 8 Flooding at Mercy Medical Center Aerial photo of flooded Mercy Medical Center Mercy Medical Center is one of two major medical facilities in Cedar Rapids and is adjacent to but not directly in the 500-year floodplain. Flooding came from several sources, though the primary flooding sources were sanitary sewer backup through toilets and sinks and groundwater seepage. Most of the flooding occurred in the basement of the hospital, which led to irreparable damage to medical equipment including a Magnetic Resonance Imaging (MRI) machine, two Computed Tomography (CT) computers, and pharmaceutical robotics. In addition, the communications systems, UPS systems, electrical distribution panels, mechanical controls, elevators, security systems, and radio center suffered severe damages. Mercy Medical Center was operating at 90% of its full function 2 months after the floods. Structures that are near but not directly inside a floodplain still face a residual flood risk, and should plan accordingly. SLIDE 9 Gays Mills, Wisconsin Gays Mills experienced flooding in both 2007 and 2008 Map showing the flood zones in Gays Mills. Two photos showing flooded streets and homes in the city. SLIDE 10 Reedsburg, Wisconsin Power at the Reedsburg Sewer Pump Station was lost Emergency generator could not be run because natural gas had been shut off by the city as part of its emergency procedures Pump station’s wet well and portions of the sewer collection system backed up and became surcharged. This event resulted in sewer backups in homes, commercial buildings, and public facilities. Photo of the pumping station, and aerial view showing the location of the site, and a map showing where is fell in the flood zone. SLIDE 11 Numerous Foundation Wall Failures Photos showing that unreinforced Masonry Foundation Wall failure was probably the most common observation. SLIDE 12 Prematurely Pumped Water Out of Basement Photo of Prematurely pumped out basement, only one confirmed/seen by the MAT SLIDE 13 Coralville, Iowa • this slide contains animation. Blue = 100-year Floodplain, Pink = 500- year Floodplain, Dark Blue = River • A dam on the Iowa River just upstream from the city of Coralville, Iowa. • The lake and surrounding lakeshore have been extensively developed for recreational use. • Water first flowed over the 712-foot emergency spillway on July 5, 1993, reaching a then-record crest. The record was surpassed by the June 2008 Midwest floods. • Coralville, Iowa (Iowa City, Iowa), note Interstate construction (I-80) on first aerial, next aerial late 90s/early 2000s, last aerial 2007. • Edgewater Park represents a Native American campsite located along the banks of the Iowa River that was occupied around 3,500–3,550 years ago (2,000–2,050 B.C). Over the years, the site has been covered by flood deposits from the Iowa River. Edgewater is estimated to be the oldest site in Iowa with evidence of domesticated plant use. Studied by the University of Iowa before Coralville Marriott Hotel and Conference Center was built. • Edgewater Drive – row of residential properties (most of which were substantially damaged). • Coralville Marriott Hotel and Conference Center completed in 2006; 265,000 square feet along with River Bend Condominiums and Retail/Office Suites. SLIDE 14 Coralville, Iowa Several properties along Edgewater Drive were substantially damaged. 3 photos showing a damaged home and the location on an aerial and an oblique aerial. SLIDE 15 Coralville, Iowa Elevation project where homeowner ‘kept’ basement, flagged during a CAV prior to 2008 floods. Some basement exceptions had been granted in certain areas visited by the MAT— those homes had engineered basements with drainage systems and sump pumps, and for the most part performed as designed (La Porte City, IA). This was a violation. This is the same home shown in the slide above prior to flood damage. SLIDE 16 Idyllwild Subdivision This slide contains animation. Blue = 100-year Floodplain and Pink = 500-year Floodplain according to Digital Q3 Flood Data Subdivision built in the early 1990s in Iowa City, Iowa. Most of the development was considered outside the floodplain based on Letter of Map Revision (LOMR); it suffered extensive damages. $2 million cleaning fee for the subdivision; $22,000 per unit. Two months after the flood, only one residence of more than 90 was occupied in the subdivision. This subdivision underscores the importance of communicating risk even for areas that are considered to be outside the floodplain. SLIDE 17 Photo 1 – Most of the subdivision consisted of adjoining units; this one included one with all the living areas on the second floor and the adjacent unit’s living area was primarily on the first floor. Photo 2 - All living areas located on the second floor along with the hot water heater, air handling unit, laundry room, and kitchen, which illustrates the benefits of performance-based design. Photo 3 and 4 - The adjoining unit suffered 3 to 5 feet of floodwater and two to three times the economic losses due to it being a single-story at-grade unit while the surviving neighbor with living area on the second floor only had a garage at the grade level. SLIDE 18 Oakville, Iowa Aerial photo showing the area South of the Cedar/Iowa River junction. Area protected by a levee which was breached; several hundred properties were substantially damaged (6 to 8 feet of water in most homes). Small town heavily impacted. Evidence of erosion and high velocity flow closer to levee failure. SLIDE 19 Oakville, Iowa South of the Cedar/Iowa River junction. Area protected by a levee which was breached; several hundred properties were substantially damaged (6 to 8 feet of water in most homes). Small town heavily impacted. Evidence of erosion and high velocity flow closer to levee failure. Photo 1 showing a damaged elevated home. Photo 2 showing the high water mark on the wall of a structure. SLIDE 20 Oakville, Iowa Photo showing a house removed from foundation SLIDE 21 Oakville, Iowa Photo 1 showing connections every 6’ to 7’ Photo 2 showing garage which was bolted to foundation remained. SLIDE 22 Recent Elevated Construction Photo of a home in River Front Estates, Iowa City, Iowa Map showing floodplains: Blue = 100-year Floodplain, Pink = 500-year Floodplain, Dark Blue = Major Hydrology SLIDE 23 House with garage had: Photo 1: Openings in foundation wall (both garage and house) Photos 2 & 3: Elevated air conditioning/heat pump compressor. SLIDE 24 Closer look openings were covered/obstructed (Photos 1 and 2) Openings were covered during the flood, one even sandbagged (Photo 3). SLIDE 25 Openings Home in New Hartford, IA had openings too high SLIDE 26 Elevation, Post-Event Photo of a home after the event being elevated. North Shore, Wisconsin (Lake Koshkonong). SLIDE 27 Elevation, Post-Event Photo of a home after the event being elevated. North Shore, Wisconsin (Lake Koshkonong). SLIDE 28 Elevation, Post-Event Photo of a foundation prepared with bolts SLIDE 29 Elevation, Post-Event Photo of an elevation where homeowner kept basement. Flood map showing where it was located. SLIDE 30 Dry Floodproofing Three photos of a home in Spring Green, WI with dry floodproofing SLIDE 31 Poorly Located Utilities Photo of a utility box located too low. Columbus Junction Water/Public Works SLIDE 32 Raised Utilities, Pre-Event Photo of a structure with raised utility unite. La Valle, Wisconsin SLIDE 33 Raised Generator, Post-Event Two photos showing the before and after of a raised generator. La Valle, Wisconsin SLIDE 34 Cedar Rapids Critical Facilities Flood map showing three facilities on an island in Cedar River Island is in SFHA All facilities connected by subgrade parking garage Pedestrian access tunnels were a major source of flooding in all three facilities SLIDE 35 Cedar Rapids Critical Facilities Aerial photo showing the location of the Linn County Courthouse, Linn County Detention Center City Hall, and police department headquarters; all flooded. SLIDE 36 Photo showing an Underground Parking Structure SLIDE 37 Photo showing the Access Tunnel to Courthouse SLIDE 38 CRPD Headquarters Photo of the CRPD built its headquarters in 1997. The structure is located outside of the SFHA, but in the 0.2-percent-annual- chance floodplain During the June 2008 floods, the walk-out basement was inundated with 7 feet of river water and raw sewage Built 1 foot above the BFE and 4.5 feet below the 0.2-percent-annual-chance flood elevation. SLIDE 39 Photo of the CRPD Headquarters flooded. SLIDE 40 Flood map of showing the location of the Reedsburg waste water treatment facility SLIDE 41 Aerial view of the Reedsburg waste water treatment facility with the earthen berm shown in a red line. The Reedsburg WWTF was constructed in 1939 and is in the SFHA (Figure 4 21). The facility is currently designed with a 2.6-million-gallons-per-day (MGD) capacity to serve approximately 10,000 people. The earthen berm protecting the Reedsburg Wastewater Treatment Facility (WWTF) was overtopped during the 2008, causing the plant to cease operations. As a result of the shut-down, untreated sewer water was discharged into the Baraboo River. In addition, the access road to the facility was flooded and became impassable. The WWTF in Jefferson, WI had a similar set-up—a continuous berm protected the facility. However Jefferson’s fuel site was outside the berm and was flooded out. The city had to procure an emergency fuel contract. SLIDE 42 Photo of the Reedsburg WWTF Access Road SLIDE 43 Flood map showing the location of the Baraboo WWTF Most equipment inside the City of Baraboo Wastewater Treatment Facility was elevated and suffered little or no damage. A manhole cover replacement program successfully protected sewers from inundation during the floods. However, the access road to the main plant was flooded and impassable. Due to the flooding on the access road, it was not possible to transport a generator to a downed pump station. The WWTF structures were built 2 feet above the BFE, which is approximately 819 feet. The 0.2-percent-annual-chance flood elevation is approximately 821 feet. SLIDE 44 Photo of the front entrance of the Baraboo WWTF flooded. SLIDE 45 Photo of the Baraboo WWTF flooded. SLIDE 46 Photo of the Baraboo WWTF Access Road flooded. SLIDE 47 Photo of the Des Moines Water Works Not a design event in this area Highlighting based on action taken since 1993 SLIDE 48 Photo of the Des Moines Water Works access road Integrated access road into protective berm SLIDE 49 Floodplain Debris Photo of Boathouses Photos of Unanchored storage tanks SLIDE 50 Acquisitions Map showing the location of acquisitions Following the 2008 Midwest floods, the MAT visited several communities in Iowa and Wisconsin. This illustration shows 127 properties in the 1-percent-annual- chance flood zone that have been acquired or relocated through a FEMA-funded program. 24 of the remaining properties – ones that for whatever reason did not participate in an acquisition project – sustained greater than 50% damage during the Midwest floods of 2008. Another 22 sustained 1 to 49% damage. Acquisition projects are the most effective mitigation measure because they eliminate the flood risk for that property. SLIDE 51 Conclusions and Recommendations Basements –removing/filling in the basement when rebuilding –reinforcing foundation walls during repairs –outreach on hazard associated with prematurely pumping water out of their basements Foundations –importance of securing existing buildings that are being elevated on new foundations –openings in foundation walls in accordance with published FEMA guidance SLIDE 52 Conclusions and Recommendations Residential development –elevation as it relates to new construction and adopting freeboard requirement for additional protection –substantial improvements and repair of substantially damaged properties –consideration of installing backflow prevention valves to prevent avoidable flooding in buildings SLIDE 53 Conclusions and Recommendations Critical Facilities –site selection for new and replacement facilities –location of equipment and utilities –systematic reduction of inflows from major users –staging of emergency equipment Mitigation grant programs –Acquisition SLIDE 54 Conclusions and Recommendations Floodplain management –flood risk communication –promotion of the National Flood Insurance Program Community Rating System –sources of debris in the floodplain –locally run programs to fund mitigation projects –flood insurance and mapping SLIDE 55 FEMA Building Science Flood/Wind Building Science Helpline: FEMA-BuildingScienceHelp@dhs.gov (866) 927-2104 http://www.FEMA.gov/Rebuild/BuildingScience