East Otter Tail Groundwater Protection
Many of the aquifers that are located under Otter Tail County are susceptible to contamination from nitrates and other water soluble contaminants due to the coarse grained soils of the area. These aquifers are used by municipalities and rural residents. One of the common agricultural practices in the area that can have an effect on these aquifers is agricultural irrigation. Over application of irrigation can directly lead to leaching of nutrients that can contaminate our groundwater resources.
This project will provide cost-share and incentives to ag producers to convert irrigation systems to low pressure systems and manage the application of their irrigation to prevent potential groundwater contamination due to overwatering. The conversion from a high or medium pressure irrigation system to a low pressure system improves the efficiency of water use through the system. This reduces the draw on the groundwater resource by an estimated 25% to 30%. The reduced pumping also reduces energy use by an estimated 10% - 35%.
Cooperating producers will also be able to use the East Otter Tail SWCD's Irrigation Scheduler Program. This is a service that provides producers with in the field soil moisture status to assist them with the decision of when to irrigate. Weather conditions, rain events, irrigation events, crop type and crop development stage are all used to determine the amount of water being used by the plant. This information is used to provide a weekly soil moisture graph to the producer. When used properly this program prevents crop loss due to insufficient moisture, reduces ground water contamination due to over application of water resulting in leaching of nutrients and chemicals, reduces energy use, and reduces the amount of water pumped from the aquifer.
(c) $3,000,000 the first year and $3,000,000 the second year are for nonpoint source pollution reduction and restoration grants to watershed districts, watershed management organizations, counties, and soil and water conservation districts for grants in addition to grants available under paragraphs (a) and (b) to keep water on the land and to protect, enhance, and restore water quality in lakes, rivers, and streams, and to protect groundwater and drinking water. The projects must be of long-lasting public benefit, include a local match, and be consistent with TMDL implementation plans or local water management plans. Up to five percent may be used for administering the grants (2011 - Clean Water Assistance)
The conversion from a high or medium pressure irrigation system to a low pressure system improves the efficiency of water use through the system. This reduces the draw on the groundwater resource by an estimated 25% to 30%. The reduced pumping also reduces energy use by an estimated 10% - 35%.
The East Otter Tail SWCD funded nine cost-share contracts with these funds. These contracts resulted in 11 low pressure conversions on a total of 632 acres, and 18 fields being enrolled into an Irrigations Scheduling Program for a period of at least 2 years (1,225 acres/year). This resulted in pollution reduction estimate of over 11,550 pounds per year of nitorgen being lost into very suspectible ground water resources.