Timely rain helped reduce groundwater demand in 2017

Timely rainfall during the 2017 growing season helped reduce groundwater demand, according to data from the HPWD Irrigation Assessment Program.

Since the program's reinstatement in 2013, cooperating producers have volunteered to have their center pivot or subsurface drip irrigation system evaluated by HPWD staff. 

Data collected during the 2017 growing season are shown in the graphic at right. This was gathered from 580 wells at 113 irrigation system sites within the District's 16-county service area.

Water levels in wells are measured at the beginning and end of the growing season. In addition, flow rates of the wells/irrigation systems are checked with an ultrasonic flow meter. This service is provided by HPWD at no cost to willing participants.

The pumping hours, total gallons of water per minute, and the number of irrigated acres are calculated to determine the total acre-inches of groundwater applied during the growing season.  

Rainfall totals are determined through the use of  radar estimates from April to September. This gives an estimate of the total inches of water available for plant use.

Water samples are also collected as an extra service to those participating in the program. HPWD is able to check Total Dissolved Solids (TDS), chloride, and pH levels of groundwater. It is important to understand water chemistry since it impacts the efficient use of supplemental nutrients applied to crops.

This information is used to better understand the groundwater conditions in aquifers within the HPWD service area. 

For example, the 2017 program participants' well data revealed an average depth-to-water of 216 feet and an average flow rate of 110 gallons per minute. 

All data gathered from each site is shared with program participants. 

Several producers have said the data has helped them better understand their irrigation system's performance.