This position statement addresses increasingly devastating flood events in the context of agricultural water management and functional political jurisdictions. It is important for water conservation in the face of global warming, and has potential to increase wildlife habitat and recreational opportunities in the rural areas surrounding urban populations. It can likely be implemented by reallocating flood control and damage expenses to cover the cost of water management in the headwater watersheds of the Mississippi River drainage area. The solution is likely attainable without new resources, rather by allocation and efficiency in use of existing resources.
In addition to frequent flood events, agricultural run-off in the Mississippi River watershed generates substantial levels of agricultural nutrient pollution. The most troubling of these nutrients are nitrogen and phosphorous. These cause algae blooms (sometimes toxic) throughout the watershed which substantially increase the costs of water treatment for human and industrial consumption where water is provided by the watershed’s rivers. Algal blooms are killing fisheries in the lower watershed and the Gulf of Mexico (much as they are in Lake Erie, Florida, the Chesapeake Bay and other water resources draining agricultural areas).
The dual problems of flooding and nutrient pollution largely originate on rural agricultural land. While not all rural land is agricultural land, agricultural land is heavily fertilized and artificially drained. Both of these characteristics make agricultural land the primary starting point in the quest to reduce flooding and nutrient pollution.
Since 1980, Iowa has experienced 27 flood events that cost at least $1 billion. Conservatively, together these events have cost over $41 B. On June 13, 2019, the Mississippi river dropped below flood stage in Dubuque, Iowa for the first time in 85 days. On June 18, 2019, the river dropped below flood stage in Davenport, Iowa for the first time in 96 days. Through August, the river at Davenport had been above flood stage for 124 days—over half of 2019 up to that point. Flooding is no longer a disaster management issue in the Mississippi watershed. It is a fiscal planning issue: It is the new normal.
The City of Davenport business community estimated that lost business due to flooding (not counting property damage) was $2.5 million (M) per month. In May, the Davenport Department of Public Works claimed that it had already experienced over $1 M in damages. That does not count the other communities in the metropolitan area, private damages, or county- and state-level losses in the area. Des Moines, Iowa currently commits $11 M/year to flood mitigation projects and committed an additional $10.5 M for flood buyouts in 2018. FEMA spends over $7 M/year on Iowa flood declarations. The City of Cedar Rapids has committed $37 M/year for 20 years to complete a major levy project. Davenport is considering upwards of $175 M for a floodwall system that will undoubtedly shift flooding to other, unwalled, communities in the watershed. In 2016, the Iowa Flood Mitigation Board allocated $1.5 B to just 10 Iowa communities for mitigation projects.
This list came from a quick scan of online public records and news sources. It is not a systematic analysis of state or local budgets for ongoing or extraordinary allocations. It does not account for damages from the continuous stream of small (under $1 B in damages) events occurring within the state. In his 2019 Iowa Water Conference presentation, Witold Krajewski, Director of the Iowa Flood Center, demonstrated that this consistent pattern of smaller floods leads to greater cumulative damage than that caused by intermittent major flood events. It is almost certain that over $2 B is committed to flood control, mitigation, and damage in Iowa on an average annual basis.
This flooding, and the normal flows that hyphenate it, also carries agricultural pollution. Recent research from the University of Iowa estimates that the 5-year average nitrate nitrogen load leaving Iowa in rivers was 300,000 tons in 2016. This is up by almost 50% from the 5-year average in 2003. In terms of annual loading, Iowa discharged approximately 350,000 tons of nitrate nitrogen in 2013 (the year the state implemented the Iowa Nutrient Reduction Strategy). In 2016, this discharge was 650,000 tons.
How can nitrogen loads be increasing when it is state policy and the stated policy objective of Iowa’s commodity organizations to solve this problem? Simply put, the policy efforts in place to deal with these problems are all designed to meet the needs of agricultural production rather than downstream water consumers. For example,
Flood control is not addressed:
There are no provisions for taking land out of production to capture abnormally high runoff quantities for controlled release over longer periods of time;
Draining agricultural land takes precedence over nutrient reduction:
Recommended treatment options allow runoff bypass during above-normal runoff events, meaning flood waters (when nutrient loss and pollution are highest) are largely untreated;
There are no restrictions on agricultural drainage
In effect, nutrient reduction policy in Iowa gives preference to pushing runoff downstream, rather than treating excess water quantity and nutrient pollution upstream. This preference neuters nutrient reduction efforts as it exacerbates downstream flooding.
Des Moines River flow statistics and drainage estimates from the Iowa Nutrient Reduction Strategy provide some idea of internal flows in Iowa. While Iowa cannot control Mississippi and Missouri River flooding that originates as runoff in upstream states, an accounting of in-state runoff is helpful to understand the context of Iowa flooding. It is also helpful in that measures taken within Iowa to control internal flows could, if mirrored by other states, substantially mitigate the major-river flooding that occurs along Iowa’s borders.
The Des Moines River has the second largest discharge of any Iowa river (slightly below the flow rate of the Iowa River). Its flows are representative of flows on the Iowa River, the Skunk River, and other Iowa rivers. Its 10-year average annual discharge at Keosauqua was 404.6 B cubic feet in 2016 (9.3 million acre-feet (a-f) or 0.98 a-f per drained acre). The 10-year annual discharge average has increased 38.5% over the past 30 years—partially due to increased rainfall and partially due to expansion of agricultural drainage infrastructure. The increase equals 3,565 cubic feet per second (cfs) at Keosauqua every second of the year —one acre-foot every 12.2 seconds.
This is not delivered as averages. It comes as trickles and torrents. Between 2007 and 2016, the daily average discharge ranged from 196 cfs to 105,000 cfs. More than half (59%) of discharge came on the 25% of days with flows over 20,200 cfs.
Controlled water storage on small sites in the headwater areas of the watershed could conceivably eliminate the damages done downstream at peak flows. Holding back flows over 25,000 cfs could have been accomplished in 2010 (the peak flow year in this data set) with a maximum held volume of 5.1 M acre-feet. Constructing multiple small pools averaging four feet deep in headwater watersheds could pool 1 M acre-feet by using 250,000 acres for impoundment. If for every four acres of intermittently flooded land we held one acre of permanent wetland, we would need 50,000 acres of permanent wetland and 200,000 acres of intermittently flooded land (that could continue to be farmed or used for recreation and wildlife habitat). Assuming:
$10,000/acre for 50,000 acres of permanent wetland,
$2,500/acre to prepare 250,000 acres for pooling, and
$150/acre for crop insurance on 200,000 of those acres (to cover lost crop every 4–5 years),
the cost of pooling 1 M acre-feet would be a $1.125 B capital investment plus annual operating and insurance costs. With three years’ worth of average annual flood-related expenditures in Iowa, we could virtually eliminate expected peak flooding on the Des Moines River. In 10–12 years, we could virtually eliminate peak flooding throughout Iowa. Iowa’s continuous smaller flood events could be addressed with less money.
Why don’t we do it? Because the political jurisdictions that suffer the damages and incur the expenditures are different from the political jurisdictions that originate and accelerate the flows of water. As long as we treat this as a local problem, and local political jurisdictions separate those who suffer the costs of water flows and pollution from those that reap the benefits of agricultural drainage, we condemn ourselves to spending funds on flood damages and infrastructure. Those funds could be reallocated to solve the flooding problem.
Local jurisdictions that prevent the necessary transfers of funds are often defined along land-use lines, placing boundaries between urban and rural areas. This leads to a preoccupation with the “Rural-Urban Divide” when our attention and investments might more effectively be placed along the “Inter-Urban Frontier”. Shifting our attention and our functional jurisdictional boundaries outward would allow investment at micro- and meso- environment scales for flood mitigation where the water originates on a macro-scale.
Advantages to urban areas would include flood control, better ability to address nutrient runoff at its source, and increased recreational and environmental resources. Rural areas would also benefit from flood and nutrient control. Holding water in the headwater regions of watersheds will provide Iowa Falls and Marengo as much flood control as is afforded to Des Moines and Iowa City. Additionally, rural areas should see major benefits from soil-moisture conservation. Recent trends show annual rainfall increasing in the Midwest and becoming more concentrated in the spring and fall. This increases the risks of planting and harvest disruption as well as growing-season drought. Holding spring moisture into the growing season is one of the observed benefits of the Waffle Project in the Red River Valley of Minnesota and North Dakota.
First, it seems we need to focus on generating solutions rather than generating research opportunities. The twin problems generated by agricultural runoff for urban and rural areas, and the environment in general, are not primarily opportunities for academia. Academia is a tool for resolution, which should have a specific focus on problem resolution if it is justified on the basis of problem existence. A report of the Iowa Public Policy Project recently pointed out that a large portion of funding provided by state and federal government sources to support the Iowa nutrient reduction effort have nothing to do with nutrient reduction. This happens too often.
Second, I am reminded that John F. Kennedy’s challenge to reach the moon in a decade was predicated on the fact that most of the basic scientific knowledge needed for the effort already existed. The major challenge was to identify, integrate, and more creatively utilize existing knowledge to address a new opportunity. Leonardo Da Vinci’s broad contributions to knowledge may have been so impressive because he moved sideways as often as he forged ahead.
Solving urban, rural and general environmental issues caused by agricultural runoff require two things:
New money is probably not on the table in the current political environment, so locating sources of money that can be effectively reallocated (reallocated without abandoning the benefits of current allocations) is key.
To resolve flooding and nutrient pollution issues arising from agricultural runoff, we need:
Reliable estimates of total public funding consumed by flood damages and construction of flood control infrastructure, total private expenditures on flood insurance and loss, and total public expenditures on water treatment due to agricultural nutrient pollution. The locations associated with these sums need to be identified spatially with GIS databases. These spatial representations need to be integrated with topographic features to analyze their relationship to areas where runoff originates. If existing funding can be identified and placed with respect to macro-system needs, much of this becomes a design problem, and could be further addressed by applied research in public finance and political science.
Improved systems to monitor precipitation, runoff origination, and tributary flows and convergence. Controlling excessive macro-flows on downstream watersheds by controlling runoff on a smaller scale in headwater areas of a watershed is a complex problem that requires real-time flow data and predictions. The University of Iowa’s flood information system provides a partial framework for accomplishing this. Flow and convergence data throughout the watershed are needed to maximize the reallocation of funds called for in the design problem above and could be further addressed by applied research in geology, atmospheric science, hydrology, and engineering.
Modified micro- and meso-scale political jurisdictions and/or relationships that facilitate moving identified funding across the jurisdictional boundaries that separate runoff origination from runoff damages, which could be further addressed by applied research in political science.
Integration of runoff control with other public infrastructure development and maintenance and public investments in recreation. The Waffle Project on the Red River in Minnesota and North Dakota is investigating the modification of existing roadbeds and ditch networks to temporarily hold water during major runoff events and release it in a controlled fashion as flows diminish. There are large portions of Iowa, Illinois, Minnesota, Indiana, and Ohio to which the underlying concept would apply. Recent survey results indicated that Iowa off-road vehicle owners were interested in increasing the number of small, closely-spaced recreational areas across the rural landscape. Respondents also overwhelmingly indicated a willingness to help pay for such investments. Utilizing existing and potential infrastructure and recreational investments to control flows could be effective if we can monitor, predict, and manage those flows, which could be investigated through applied research in civil and environmental engineering.
Modified agricultural subsidy and insurance systems designed to indemnify farmers for potential flood losses due to Waffle-Project-like systems or pooling systems set up for intermittent flooding which could be supported by applied research in agricultural finance.
Utilization of eminent domain, if necessary, to attain effective and efficient placement of runoff ponding/treatment facilities and infrastructure.
Expansion of flow monitoring to include nutrient monitoring to identify watershed segments that require treatment on a micro-scale before entering the the macro-watershed. This would also facilitate remedial actions in areas where production practices need modification or sanction. It is possible that this effort could initially be self-funded through nutrient or pollution taxes on micro-scale nutrient-flow offenders, and could be supported by applied research in public finance, hydrology, and agronomy.
Much of the knowledge required to resolve these problems already exists or is in some identifiable stage of development and refinement. It is often noted that most problems are technically manageable but socially impossible. That is certainly the case for the flooding and nutrient pollution challenges agricultural runoff imposes on downstream environments.
Senior Consultant, Regional Strategic, Ltd., Des Moines, Iowa
This event is supported by the National Science Foundation, Award #1929601. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.