Wet harvest can lead to wet planting - The risk of farmland flooding
Mar 08, 2010
The planting season is right around the corner and that means that flood season is coming even quicker. After an extremely wet harvest across the nation, fields that have not had their fall tillage completed may be at a disadvantage when spring comes. Fields that still have crops standing in them will even further delay the planting season. Two to four times the normal precipitation level was seen in the Midwest this past fall, according to the National Weather Service.
As snow melts and the ground is exposed to the sun once again, the ground needs to heat up and dry out as quickly as possible so farmers can access the fields to plant their crop. Flooding becomes an issue in spring when fields cannot drain their moisture quick enough.
The snow pack of the upper Midwest was impressive this year. December brought 150% to 400% the normal amount of precipitation to areas in North Dakota, South Dakota, and Minnesota. Although snow did not come until mid December in many parts, sub-zero temperatures created an extremely thick frost layer in the ground, according to the 2010 National Hydrologic Assessment by the National Weather Service. This thick frost layer does an excellent job of killing pests and fungus that destroy crops during the growing season, but it will cause for an extended thaw period and increased amount of water runoff.
Conditions to prevent flooding
Even though there is an abnormal amount of moisture in and on top of many farm fields, there is still hope for a successful thaw. Temperatures mildly above freezing help melt the snow and encourage the frost to thaw which will promote drainage. Temperatures have lately been in the 40’s in many of the flood prone areas.
The best case scenario for the spring thaw would be a slow snowmelt that allows the frost to come out of the ground before any rain enters the forecast, according to the United States Geological Survey (USGS). When the ground thaws, moisture is able to start draining instead of running off. If the frost is extremely thick in the ground, a slow and steady runoff should not overpower river and stream levels until the frost eventually thaws.
The worst case scenario would involve rain. Rain is the biggest cause for flood concern during the spring thaw. If the snowmelt occurs very quickly, and more precipitation comes before the ground is able to thaw, then the risk for flooding increases dramatically.
On March 5th, the National Weather Service released an updated flood report. It stated that conditions have been favorable for a healthy snowmelt. Rivers have been at elevated levels during winter and the snow pack has been above normal as well. These conditions increase the risk of flooding, although the National Weather Service noted that if precipitation stays at minimal levels and the snowmelt continues at a steady pace, flood risks may decrease. The 90 day precipitation outlook for the nation is favorable for the Midwest.
Currently rivers and streams are well below flood stage, but 150% to 200% above historical averages for this time of year, according to the USGS. It will be a few more weeks before rivers start to feel the effects of the warmer temperatures across the U.S. and we can predict an increase or decrease in flood risk.
How to decrease the already minimal risks of owning farmland
Farmland has proven that it is a very safe and nonvolatile asset class over the past century (read “Why Invest in Farmland?” http://farmlandforecast.colvin-co.com/2009/02/12/why-invest-in-farmland.aspx), but as with any investment, there are some risks involved. Natural disaster is one of these risks of owning farmland. Flooding and drought can affect the quality of crops grown on farmland, and in even some cases, ruin the land for years.
Central Wisconsin is home to a fair amount of cropland, but the land has been scarred since the flood of 2008. Productive land still sits underwater along I-94 because of the flood. When a field is underwater it not only looses significant value, it will not yield any intermittent income from a cash rent contract.
To hedge the risk of owning farmland, investors should diversify their holdings of land. Farmland around the area of the Red River Basin has great value, but flooding occurs almost annually in many parts. It is best to spread out the risk by holding land in different areas across the Midwest.
Remember to visit Farmland Forecast (farmlandforecast.colvin-co.com) for your daily update on news and research about agriculture and farmland.