Dutch Flood Policy Innovations for California

Flood risk management is an important part of life in the Netherlands. The Netherlands is formed by the deltas of three rivers- the Scheldt (rain-fed, originating in southern Belgium), the Meuse (rain-fed, originating in northern France), and the Rhine (glacier and rain-fed, originating in Switzerland). The country also borders the North Sea, with the Scheldt River connecting the sea to Antwerp Harbor. The Rhine is the largest of the three rivers, splitting into three branches (the Ijssel, the Lek, and the Waal) as it crosses the border into the Netherlands (Tol et al. 2003). Two-thirds of the country lies below mean sea level (Voortman 2003). The Dutch have a long history of attempting to control floods. As early as the ninth century, the Dutch started building dikes to protect reclaimed bog land (Kaijser 2002). These dikes started as local, individually-owned structures, but communities soon realized that closed dike rings were necessary to protect all sides of the region. These dike rings eventually became waterschaps or “waterships,” regional districts charged with water management including drainage and dike building. These districts are still the administrative body for flood defense (Linsten 2002, Voortman 2003). The 14th century saw the first major recorded floods in 1313 and 1315, leading to the famine from 1314-1317 that killed 5-10 percent of the population. Periodic flooding continued through much of the Netherlands’ history. As sediment settled between the dikes, dikes grew taller. During the 19th century, reorganization of the water districts occurred and a national body was formed. Military engineers took over the construction and maintenance of the dike system (Tol and Langen 2000). During the 20th century, as trained engineers and the central government took over flood control efforts, the analysis of appropriate techniques and construction increased (Disco and van dev Ende 2003). Prior to 1953 dikes were built to the height of the previously known high-water level plus a margin of safety (Jonkman et al. 2004). Following the catastrophic flood of 1953, the Delta Committee was formed to advise the government regarding flood control (Voortman 2003). One recommendation of the Committee was to establish an optimal exceedance frequency of the design water level based on risk of flooding and cost of protection. Van Dantzig's 1956 paper described this risk-based calculation. He proposed that flood management required integration of three areas with noted problems: statistics, hydrology, and economics. In the past 50 years, significant effort has been devoted to expanding on van Dantzig's work and working on solutions to the problems he noted and the assumptions he made. Increased computing power, additional rainfall and hydrologic data, and watershed models have all added to the understanding of flooding while increased emergency preparedness and response have enhanced protection of land, homes, farms, businesses, and lives. Northern California also has a history of devastating floods, although the history of floods and water management is much shorter than in the Netherlands. Throughout the past century and a half, winter rains and snowmelt have resulted in flood events that have caused billions of dollars in damage and multiple deaths. One of the largest floods in California history occurred in January, 1862 following four weeks of rain. No quantitative flows are known, but the banks of the Sacramento were breached and the water was, at minimum, three feet deep from Sutter's Fort to Davis (Harding 1960). This flood also brought significant mining debris, covering the land near Marysville with one to six feet of sediment. During the second half of the 19th century, mining techniques had developed from ditch and flume operations to high powered hydraulic techniques that discharged up to a million gallons an hour from a single nozzle (Kelley 1989, Larson 1996). Over 1.5 billion cubic yards of sediment was discharged into the Feather, Yuba, Bear and American River basins from hydraulic mines (Larson 1996). However, the litigation between Woodruff and North Bloomfield Gravel Mining Company (1884) effectively stopped hydraulic mining by requiring complete containment of debris. Early in the settlement of California, flood control was typically very local, with levees built by individuals or local governments. Following this major flood in 1862 and the resulting litigation, hydraulic mining ended and levee management moved to larger regional agencies and the state government. The largest recorded flows in the Sacramento River were reached during the flood of March 1907. Although some tributaries have since exceeded their 1907 flows, the Sacramento River has not exceeded its peak flow of about 600,000 cubic feet per second (16,990 m3/s) (Harding 1960). Thirty to forty inches of precipitation across Northern California during the week before Christmas in 1955 led to severe damages and levee failures. Seventy-four lives were lost and over $200 million in economic losses were attributed to the flood (Harding 1960). Record rainfalls led to major flooding in 1986. Levee breaks in the Sacramento River Basin led to 13 deaths and over $400 million in damages. Two of the most expensive floods in California's history (1995 and 1997) occurred within two years of each other and together caused nearly $4 billion in damages (Department of Water Resources website). Early in California's history, no state or federal agencies managed flood control; flood control projects were managed locally. As settlement increased, however, state and federal funding and regional management became necessary. First, state and county agencies began acting to prevent flooding and then in 1917, federal authority for flood management was granted by Congress. Since then, there has been a fluctuating balance of power between regional and district, state, and federal flood control planning, funding, and management (Kelley 1989). Six types of actions can be considered for flood management (Hoojier et al. 2004): Actions to prevent flood generation: land use management in the upstream basin, Actions to modify flood flows and elevations: flood storage, levees, by-passes, and channel improvements, Flood damage reduction actions: floodplain zoning, building codes, awareness raising, Preparatory actions: flood forecasting, warning and emergency plans, Flood event actions: crisis management, evacuation, and Post-flooding actions: aftercare, financial compensation, insurance. The Dutch concentrated mostly on preventive flood control measures, and many of the measures implemented in California were first tested by the Dutch in their attempt to control flood waters. Some more recent Dutch innovations might increase California's ability to reduce flood damage. This paper is organized into three subjects. First is a review of Dutch flood control innovations. Next, implementation of each measure is discussed in California's context. The final section wraps up the discussion with a summary of key points and conclusions. Dutch flood defenses have three components: dunes, dikes, and special structures. Natural sea dunes protect coastal areas from tides and storm surges. The dunes are planted with helm grasses to hinder erosion. Where there are no dunes, the Dutch built dikes. The dikes, initially constructed along the river, have become dike rings to provide protection on all sides. The 1500 mile dike system in the Netherlands includes some massive engineering and construction The for North into the and has the The dike is over and dikes are to protect upstream dike early was constructed between the and in Although this protection to it increased the damage upstream (Tol and Langen 2000). the storm that to protect and from flooding from storm surges. of the two is as as the special and In special are in as solutions in response to a flood event or storm Flood management and system are to reduce flood damages. use two to flood management risk-based and These design are described below and et al. 2000). design on the of flooding by measures has two the an event and the of that event et al. 2002). of the optimal risk-based design in the from all by their for each and the expensive design a flood as as of the damages from flood is to to a for protection of the risk-based is that it based on of and of et al. 2002, et al. et al. 2003). design is based on a or other an based on regarding of or economic be based on the previously discussed risk-based design the with the for the flood protection system and damage during flood design engineers and to a of that provide the level of protection and then the Flood protection can risk-based design for a one section of that with risk-based a can be and in a to the other of the have flood flood and the Dutch use a flooding for flood protection. The design is based on an economic optimal or risk-based The safety for a dike a and its is than the for a dike This in the design in of and the two of flood the frequency of flooding and the of are to reduce flood risk by the frequency and of flood are the most and dike or levee and and et al. the following to design is resulting in the that all areas and land use types have of of economic a was and maintenance and reduce and on the of a These land as emergency response and flood and are described as of with the of et al. 2003). One of is of land to for with In the van and the Delta Committee on three areas of flood statistics, and and economics. Van Dantzig's risk-based design for a He was the first to flood defense design quantitative analysis (Voortman 2003). In the economic van dike height to the height at the dike but the between this height and height as by breaks are of is in to national of dike height is in for dikes of other is and response and are with to van Dantzig's The is the or level of and the is the cost of the The is the cost is the of construction and maintenance as the level of protection The is the damage cost as the level of protection The is the cost and is the of the two types of The optimal risk-based design is the level of protection to the or the on the of the Dutch the of and has In however, and were into national Dutch on dike et al. et al. Since then, each has into their dike are for projects that are not as and et al. by local and is also Van the of life in for economic et al. developed the as a measure of the economic of life Voortman et al. this to the for flood protection and for life to be in and economic for flood defense However, the be important to flood damage emergency and are in flood defense flood along the Rhine to for and along the is between to of flooding et al. 2004). can to flood management in two of flood and flood damages. Flood frequency the and of hydraulic and hydrologic of flood defense and and flood and damage is a of economic and warning and preparedness et al. 2002). is to of for flood frequency et al. 2002, Van 2004). are for flood frequency and the and 2002, et al. 2004). years of from the Rhine and et al. that the of led to percent of flood in the of the of the dike system can be based on Voortman et al. as through or and through of can be a of The of all can be to the of (Voortman 2003). the defense system flood is important for the of flood damage. Flood can be a of the the or of dike and the of the flood and can be as models for flood are developed and the of are As types of are through more data, or flood risk and damage This engineers and to more flood protection and design analysis economic of all and for a flood defense design et al. not all are in the of the can be in the in than and more in the and than the flood defense system (Voortman 2003). is of flood management and risk is the risk and the of flood protection. of flood risk can construction and maintenance of flood defense and other of flood risk management are three for risk flood flood and flooding and 2004). flood risk has two crisis and levee a and to flood Levee protection measures have been and to of the protection of the system and then flood risk flood during a flood As water height and to the of the from to to and 2004). The of typically is to with flood that with flooding typically than to an or in an that has not flooding in be the single most important during high water have flooding with or no damage the risk of damage. have of life or damage in the past are most to and is as more and than the high water level and 2004). that from to are the most to during high water the of a high water event be to all are of or can together during a high water The for risk is flood event is to from to of and These typically as the flood event and 2004). risk has been into the Netherlands’ flood with to in the is more and more in flood are and 2004). that in the Netherlands no flooding as a but as a of the flood management system and 2004). This has increased the that the level of protection and in the In the of dike were for their and dike As was regional water started to were still land by the dikes and were mostly from maintenance but the had authority to the and of dikes and drainage (Tol and Langen 2002). were to dikes three a and The to be the that the work had been the was a final to problems before the a land was to the dike the at in of percent (Tol and Langen 2000). or following flood the dike by a on However, most of the financial on and led to dike this and were to of land (Tol and Langen 2000). In a and more central government led to reorganization of a national and the of a national water authority (Tol and Langen 2000). The funding for flood protection from a of and at state, and of government. are for state water for flood protection be by the national as long as within the following of the on flood protection and water management, of its and The of the the The flood protection or financial the the from the and in the dunes and dikes on the The of the by the The management of the state waters. These the Rhine with its the the the Ijssel, the the and the and and The of the In (the most recent with The Netherlands percent of its national on water management percent of was for flood protection In the years, the Dutch billion on flood protection The Water was formed in funding for the work caused by the 1953 floods was The local water were on their and formed the to at 2002). The Water is the largest Dutch and is by percent is by the water with state and government the 2002). Flood damages a financial on the government as a of for for flood and the government was for all In a special by the Netherlands’ government on flood et al. 2002). The that the government work with to flooding as a of high rains no of flood defense as part of insurance. This the to flood damage et al. 2002). can flood system Two recent and and The and with floodplain et al. have also for for dikes to be moved and the to for Although have implementation has been and et al. The Dutch are in their flood management and Van and 2004). This is important as the economic by the flood management system than dike can The economic has increased by a of six in the past years, and more in many local Two are the most as to economic of flood and flow of et al. et al. et al. 2004). In the two are part of for an led by the Dutch government to provide flood protection and use for The includes implementation of measures in the four by dike or levee flood or between the and the levees, and flood areas et al. 2004). The Dutch are building a flood along the of the Rhine to protect the of and from flood waters. This channel is built in a mostly As part of the government measure to flood protection are by the Dutch are also dikes along the Meuse between and the dikes from the river, the known as the be and water in the up to Although measures reduce land, the is to use while more of floods in areas for water and dike The have flood resulting from a for flood to the et al. et al. 2004). are first to reduce the flood height and the to flood first be as or to economic damage et al. 2003). These also can be managed to reduce and and 2002). et al. the for for Rhine flood waters. upstream is most the Netherlands have to on areas near the reduce flood water flow from an flood by million of is This is to to et al. 2004). increase of from flow to in the of the in a in et al. 2004). a to the of the and in that its at flood damages. or flood are one to increase the flow of part of a are areas water flows during flood and be for or at other et al. et al. 2004). These are to the flood in California's but with In the typically flood during the for an economic Two final for for the are levees or flood These or developed land to the levee or the In the this is of flow or most in areas with land et al. et al. 2004). The history of flood control in California is to that of the although on a were by local typically century building their defense system with a of about flood and water (Harding 1989). In the century, local, state and federal agencies began to to flood control One of the projects was in to flood that are still in (Harding 1960). The of in with state and local constructed of federal levees in the Sacramento and River also known as the Following the federal government over maintenance of the levee system to the additional of levees have been constructed by and local These levees mostly protect land with the of Sacramento and its California's levees are by the state of have been by the for flood The state, along with local and water and the system of levees, and along the Sacramento and the the flood protection system is increased as and for and land levees protect over billion in One of this increased is the of The and its of $4 billion to the local each recent of the of levees that protect from flooding on all four sides has resulted in a construction and a in required flood to and the of the levee system not the safety during a storm that has a percent of a percent of during a The construction has in an that for percent of in the Sacramento The Sacramento Flood has the levee in to its and has a to the to by This work is in part with million from a state measure in The Flood of the the flood as a to and flood and the Flood 2002). These floodplain to that are more and from flood damage than are The state of California has a flood to flood protection This flood is based and is a from a storm with a The level of protection is a event with a from a to years et al. engineers in the the a design flood plus a flood defense flood reduction measures by the the design flood was the or percent exceedance flood on and Resources in with the Flood The is to for in the and damage of a flood the has to a risk-based discussed the the Flood of it required of the following flood control However, it was not van Dantzig's work that the economic were in an early risk-based design for the hydraulic design of drainage Although early flood design was in the there was a within the to to a risk-based analysis First, the with a of exceedance and of is the is of The is then to a damage of is then to the exceedance in the first of on and Resources 2000). Following this the based on national economic This the to in projects that have a at a national level This mean that local increase the level of protection based on the economic but at the federal the additional can This not local from additional funding to the increased level of protection Some have risk-based analysis to and flood protection for in the Delta et al. and and for flood control were first in with the Flood Although this was mostly to flood control along the a Sacramento River was with federal to (Harding 1960). Over the of the federal government in was The Flood the construction of and projects as a federal by the century, the federal government had for most of the of flood control construction with the of for local typically for flood control were to some maintenance (Harding 1960). the state of California has much of the financial for levee maintenance In a billion measure for levee and flood control system with billion for levee of cost the state government billion over funding from more than in to more than million in In per in In this funding to mostly administrative and levee and are by The California Water Flood that local in the Flood as with state federal following in the 2002). In the California state that local areas in the event of a much of flood losses in the the of although North of economic losses to it for over of the losses and 2003). The has million flood covering over billion in 2002). The Flood has been one of the most measures at economic during a flood of the safety required of that billion in flood damages are each for construction its and that the percent during a flood event 2002). However, there is a for more maintenance of the levee The of the cost of levee in the at more than million per levee of levees in this one of the largest is to measures and funding become expensive as and the cost of the levee improvements, as in the of California a flood protection funding with the Netherlands. However, two financial in the Netherlands might areas of high requiring land to provide flood protection funding as part of the levee can be made. Although it a on the developed to the cost of the flood protection the can be One of a levee is the mile levee along Bear River near was for each in the was before the levee was to the nearly million required to the were also required to each first of flood to were of the flood risk in the The levee along Bear River near the a of the Dutch of for the The levee has an additional of that on the during floods The is also an of for it is an of a the is the largest in the Sacramento and during flood events can to the much more than the channel of the Sacramento River to to m3/s) et al. 2002). During the winter and the is to during the and the is not the land is for et al. 2002). construction started in federal funding was to the state government and flood control projects (Kelley 1989). Since its the has been the for the Sacramento and are a of much and not much water and not or The Dutch have of to the balance between flood damage and in of flood defense and the of the in economic have been by the in the The federal funding to projects with the economic to the based a to for the of the land and lives the level of protection to land as to is The of design have been but to be for flood many design in are in the early in the Netherlands and California, have more in The that some of the risk and cost of flood management, there can be economic to the local government. The local government was to on the cost of the levee construction and establish a for levee Flood in the and California in the Netherlands. In the much of the for flood damage is on the including all damage caused by a of the flood defense to protect The increase in national and local economic than the government can flood protection et al. and In the the Flood has an economic for more construction and that local and state state and federal funding from measures local in flood protection and for The an of local and state to levees and to protect for the has been for in the of the and then was to flood protection. The also the that on and However, it not work in all areas of the for the not work in California's areas or areas along the in the Sacramento This review of flood protection in the Netherlands and California has the of and risk-based is expensive to in The of flood protection levee the of the and the following a flood one that not and Flood for federal have the to the economic of the state of is an with the in in and and at the of California can be reached at is the of at the of California He can be reached at and for on an