Irrigation
Fish Screening
Washington State laws require all diversions from waters of the state to be screened to protect fish. Fish can get drawn into irrigation systems and are then either killed at the pump or stranded in the field. Fish screening in especially important to the Yakima and Columbia Rivers where two of our fish species (steelhead and bull trout) have been listed as threatened under the Endangered Species Act (ESA). The Benton Conservation District can provide technical and financial assistance to landowners who draw irrigation water from the Yakima and Columbia Rivers. A properly designed intake screen can prevent fish from getting into the system without interfering with irrigation operation. Oftentimes, a properly designed and installed fish screen can enhance pumping efficiencies. The BCD can help landowners get the right fish screen for their irrigation needs.
Irrigation Efficiency Conversions
We have assisted a variety of irrigators to convert to higher efficiency irrigation systems. These conversions offer water quality and conservation benefits as well as operational benefits for the irrigator. We offer both technical and financial assistance for these conversions. Financial assistance (cost-share) up to 75% of the total project cost may be obtained depending on your project and our funding source.
Examples include:
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Conversion from furrow/rill irrigation to a sprinkler irrigation system.
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Conversion from handline/wheeline irrigation to center pivot irrigation.
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Conversion to drip or micro-irrigation from other irrigation methods.
Come talk to us if you are looking to upgrade your irrigation system.
Irrigation Water Management
How much water to apply and when to irrigate are the two most important questions an irrigator needs to answer. An irrigator needs to know how much water their system applies over a given time and how much water does the crop consume (evapotranspiration) during a specific period. Accurate designs or detailed irrigation evaluations can define a systems application rate. Crop water use can be estimated using weather station data from networks such as Agrimet or AgWeatherNetwork.
A soil moisture monitoring system should also be used to verify the soil water is being maintained between the desirable upper and lower limits of the plant being grown. Many types of soil moisture monitoring devices are available. Categories of soil moisture monitoring systems include:
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Gravimetric (Oven dry)
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Tensiometry (Measures soil tension or suction)
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Electrical Resistance Blocks (Measures electrical resistance in the soil which is related to soil moisture).
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Neutron Scatter (emits fast neutrons and estimates water content by measuring hydrogen - not for amateurs)
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Time Domain Reflectometry (measures the dielectric constant of the soil which is dependent on soil moisture content)
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Frequency Domain Reflectometry (also known as Radio Frequency Capacitance, measures soil capacitance which is dependent on soil moisture content)
Contact us if you would like more information on irrigation water management or soil moisture monitoring techniques.
View the Irrigation Basics presentation from BCD's 2020 Small Farms Workshop by clicking here.