Irrigation Water Management (IWM) is the practice of monitoring and managing the rate, volume, and timing of water application according to the seasonal crop needs, giving consideration to the soil intake and water holding capacities. Soil moisture should be managed to obtain optimum yields, without deep percolation losses or runoff.​

Irrigation water management will help irrigators determine the effectiveness of irrigation practices, make good water management decisions, and justify making irrigation adjustment in existing systems. Tools are available to assist the landowner with irrigation water management:​
- “Checkbook” method to monitor and balance soil moisture in irrigated cropland.
- Flow meters to record instantaneous flow rates and total volume usage.
- Soil moisture meters and sensors to monitor soil water deficit.
- Soil moisture data loggers to record soil moisture history throughout the growing season.

Irrigated lands of Lower Yakima County contain many coarse to fine textured soils with small to medium amounts of organic matter. These soils have low to high water holding capacities that can allow rapid movement of excess water down through the soil profile. Irrigation Water Management is one of the keys to water resource conservation and enhanced water quality outcomes.