Compare Low Energy Precision Application (LEPA) irrigation efficiency against sprinkler and flood systems. Calculate water savings and net delivery.
Low Energy Precision Application (LEPA) is an irrigation method that delivers water from close to the ground surface into furrows or basins, virtually eliminating evaporation and wind-drift losses. LEPA systems operate on center pivots using drop tubes with drag socks or bubble nozzles instead of overhead sprinklers.
LEPA systems achieve 95–98% application efficiency compared to 75–85% for standard center-pivot sprinklers and 40–65% for flood irrigation. This means significantly less water is needed to deliver the same net amount to the root zone.
This calculator compares net water delivery across three system types (LEPA, sprinkler, flood) for a given gross application, helping you quantify water savings and evaluate the economics of upgrading your irrigation method. Whether you are a beginner or experienced professional, this free online tool provides instant, reliable results without manual computation. By automating the calculation, you save time and reduce the risk of costly errors in your planning and decision-making process.
Water savings translate directly into energy savings, reduced pumping costs, and extended aquifer life. This tool quantifies the difference so you can build a business case for converting to LEPA or compare systems when planning a new installation. Having a precise figure at your fingertips empowers better planning and more confident decisions.
Net Water (in) = Gross Water (in) × Efficiency (%/100) Loss (in) = Gross − Net Water Savings (LEPA vs Sprinkler) = Loss_sprinkler − Loss_LEPA
Result: LEPA: 0.97 in net; Sprinkler: 0.82 in; Flood: 0.55 in
With 1.0 in gross: LEPA delivers 0.97 in (0.03 loss). Sprinkler delivers 0.82 in (0.18 loss). Flood delivers 0.55 in (0.45 loss). LEPA saves 0.15 in/application vs sprinkler and 0.42 in vs flood.
LEPA was developed at Texas A&M University in the 1980s by Dr. William Lyle specifically for the water-stressed Southern High Plains. It was designed to maximize water use efficiency on center pivots irrigating from the declining Ogallala Aquifer.
A LEPA system converts a standard center pivot by replacing overhead sprinklers with drop tubes extending to 6–12 inches above the ground. Each drop is fitted with a drag sock (a rubber sock that drags on the soil) or a bubble nozzle that releases water in a gentle stream directly into the furrow.
LEPA is widely adopted in West Texas, the Oklahoma Panhandle, and western Kansas. It is also used in parts of eastern New Mexico and Colorado where groundwater is limited and the flat terrain suits the furrow-dike requirement.
LEPA stands for Low Energy Precision Application. It uses drop tubes on center pivots to deliver water very close to the soil surface, minimizing evaporation and drift. Efficiency ranges from 95–98%.
LESA (Low Elevation Spray Application) uses spray nozzles mounted 12–18 inches above the ground. LEPA uses drag socks or bubble nozzles that apply water directly into furrows. LEPA has slightly higher efficiency.
Yes. LEPA systems need furrow dikes (small dams between crop rows) to hold water in place and prevent runoff. Without dikes, water flows down the furrow and uniformity suffers.
LEPA works best on row crops (corn, cotton, sorghum) where furrows naturally exist. It is less suited to broadcast-seeded crops or permanent pasture without row structure.
LEPA operates at much lower pressure (6–10 PSI) compared to standard sprinklers (30–60 PSI). Lower pressure means smaller pumps and 30–50% less energy per acre-inch applied.
In water-limited areas like the Ogallala Aquifer region, LEPA's water savings extend well life and reduce pumping costs. Most conversions pay back in 2–5 years through water and energy savings.