New challenges for urban areas facing flood risks.

• Author: Chizewer, Debbie M.
• Position: IV. Evaluation of Flood Management Case Studies through Conclusion, with footnotes, p. 1768-1792 - 40th Anniversary Symposium

IV. EVALUATION OF FLOOD MANAGEMENT CASE STUDIES

As local governments take on more responsibility for flood management, they will inevitably look to other local governments for successful models. This section considers three case studies which can provide guidance to other cities around the nation: (1) Fargo, North Dakota-Moorhead, Minnesota, (2) Cedar Rapids, Iowa, and (3) Sacramento, California. These regions make effective case studies because they are particularly vulnerable to flooding based on their topography and development history. More importantly, each city has advanced innovative flood management initiatives consistent with principles described in the EU Floods Directive.

Fargo-Moorhead, Cedar Rapids, and Sacramento have taken steps that will help them manage floods in a more integrated manner, including the recognition of uncertainty in weather conditions and the need for better flood forecasting and the development of regional plans, and the use of some nonstructural solutions to reduce flood damage. Despite the advances in planning, however, implementation remains challenging. For instance, local governments have not consistently turned the language of integrated management into changes in land use ordinances. These local governments that have worked to develop more regional solutions have at times confronted obstacles relating to lack of coordination. These cases also demonstrate that the lack of federal requirements, substantial guidance, or consistent funding support continues to impede state and local governments from achieving optimal flood management planning.

1. Background--Case Study Areas

   1. Fargo, North Dakota-Moorhead, Minnesota

      The Red River of the North originates at the confluence of the Otter Tail and Bois de Sioux Rivers south of Fargo, North Dakota. It flows northward into Canada and forms most of the boundary between Minnesota and North Dakota. (157) The Red River's northward flow, distinctive in North America, contributes to more substantial spring floods because snow in the southern headwaters of the basin often melts before snow in the northern areas, leading to ice jams as the flow travels northward. (158) In addition, the Red River Basin is located within the broad, flat bottom valley of glacial Lake Agassiz. This topography causes the main stem and tributary rivers in the glacial lake plain area of the basin to overflow frequently onto broad floodplains. (159) The Red River Basin includes a large percentage of agricultural land, and the urban areas of Fargo, North Dakota and Moorhead, Minnesota. (160) These metropolitan areas have a combined total population of 200,000. (161)

      The Red River floods regularly. Flood damage has, on occasion, been catastrophic and has included severe structural damage to private and public facilities and infrastructure, extensive crop loss, major environmental degradation, and loss of life. Basin-wide flood damages (including both Canada and the U.S.) after the flood of 1997 were estimated at $5 billion. (162) Wetland destruction for farmland and climate change have increased the amount of precipitation and flooding in the region; the Red River has exceeded the National Weather Service flood stage of 18 feet in 48 of the past 109 years, and every year from 1993 through 2011. (163) The flood of record at Fargo-Moorhead was the 2009 spring flood with a stage of 40.8 feet on the Fargo gage. (164) Equivalent expected annual flood damages in the Fargo-Moorhead metropolitan area are estimated to be over $194.8 million in the future if no further action is taken. (165)

   2. Cedar Rapids, Iowa

      Cedar Rapids, located in east-central Iowa, is the state's second largest city with a population of 125,850 and sits on both banks of the Cedar River. (166) It is located within a shallow bowl surrounded by gentle rolling slopes. Iowa's rolling prairies and hilly oak woodlands meet at Cedar Rapids. Upland water from the entire watershed flows into Cedar Rapids. The Cedar River channel that flows through downtown does not allow for high volumes of water. Development patterns upland and the reduction of wetlands and natural vegetation, associated with development, have increased runoff and impacted the quantity and quality of the river's waters within Cedar Rapids. Much of downtown Cedar Rapids lies within the 100-year floodplain of the Cedar Rapids River. A combination of rainfall and snowmelt or heavy rainfall alone has caused the major floods. (167)

      As with many American cities, the development of Cedar Rapids necessarily relied on and altered the river. Industry's rise in Cedar Rapids correlates with the development of navigation on the Cedar River upstream to Cedar Falls/Waterloo and downstream to ports along the Mississippi River. (168) As urban and industrial development led to more flooding, efforts were undertaken to prevent the river from impairing business and residential development. The first dam was built across the Cedar River in 1841 to provide hydropower to a sawmill. (169) More millworks were developed approximately 1.4 miles upstream from Cedar Rapids. (170) The arrival of the first railroad in mid-1859 further shaped Cedar Rapid's growth by enabling the city's business to transport goods to Chicago. (171)

   3. Sacramento, California

      Sacramento, the capital city of California, was founded in 1849. (172) It is located at the confluence of the Sacramento and American Rivers. (173) The city of Sacramento has a population of 472,178, and the larger metropolitan area is home to approximately 1.4 million people. (174) Sacramento sits in the north-central part of the Central Valley. (175) The Central Valley is a broad, gently sloping valley, bounded on the west by the Coast Range, on the north by the Cascade Range, and on the east by the Sierra Nevada Range. (176) The Valley drains into the Sacramento-San Joaquin Delta (Delta). The lower-lying lands along the Valley's two major rivers, the Sacramento River and the San Joaquin River, were floodplains that were regularly inundated for long periods during large, seasonal flood events. (177) The most devastating floods are caused by warm Pacific winter storms that sweep in from the west or southwest, picking up moisture over thousands of miles of ocean, causing torrential rains when intercepted by the mountains surrounding the Valley. (178)

      Like Cedar Rapids, the rivers' current condition necessarily reflects the region's development. John Marshall's discovery of gold at Sutter's Mill in 1848 and the ensuing Gold Rush changed California dramatically. (179) The rapid industrialization of the mining and resulting debris load on the river amplified flooding in Sacramento and the Central Valley. (180) Agricultural development also contributed to the severity of floods and also led to the construction of levees at the edge of the Sacramento and San Joaquin river channels. (181) These levees were built up, rather than engineered, with readily available material including waste from the gold mining operations. (182) The vegetation that would have provided natural buffers for the water flow is almost entirely demolished. (183) Current environmental conditions and population growth place the Central Valley in a position that if a mega flood, such as those from the early 1860s, occurred now, the damage to property and business would be more than $725 billion. (184)

      With these pictures in mind, the next section uses the lens of the EU Floods Directive to evaluate current efforts to manage floods in these three areas.

2. Evaluation of Case Studies

   The EU Floods Directive provides a model for integrated flood management against which we can evaluate the innovative flood management efforts in Fargo-Moorhead, Cedar Rapids, and Sacramento. As outlined in Part III, the EU Directive requires member states to develop flood risk management plans that "address all aspects of flood risk management focusing on prevention, protection, [and] preparedness." (185) This section considers how Fargo-Moorhead, Cedar Rapids, and Sacramento address key elements of prevention and protection including the need to take into account climate change data, the importance of regional collaboration and ecosystem restoration, the role of land use planning, and structural improvements.

   1. Considering Climate Change Data

      As local governments develop flood management plans, the usefulness of their plans depends on the ability to assess flood risk and their willingness to use climate change data in that process. The EU Floods Directive emphasizes the importance of factoring in climate change, but unlike in Europe the debate over the cause and existence of climate change lingers in the United States. The need to incorporate better flood forecasting has not escaped planners addressing floods in Sacramento, Cedar Rapids, and Fargo-Moorhead. The three regions have acknowledged climate change to varying degrees.

      Leaving no doubt about its concern about climate change, the EU Floods Directive mentions climate change seven times. (186) It justifies the need for the directive by pointing out that "climate change contribute[s] to an increase in the likelihood and adverse impacts of flood events" and that previous directives do not "take into account the future changes in the risk of flooding as a result of climate change." (187) It directs member states to develop flood risk management plans that take into account the impacts of climate change and requires member states to update plans periodically to incorporate climate change data. (188)

      The State of California has gone the farthest to demonstrate a commitment to better flood risk management and need for climate change modeling. The Central Valley Flood Protection Act of 2008 (also known as Senate Bill 5 (SB5)) directly acknowledges the inability of levees to "offer complete protection from flooding." (189) It requires the Department of Water Resources (DWR) to prepare a flood management plan for the...