Diagnosing Low Water Pressure from a Well System in Arid Regions

Diagnosing Low Water Pressure from a Well System in Arid Regions

In areas with limited groundwater, like western Colorado, irrigation systems often struggle with declining well performance. This article explores why pressure drops rapidly when using a hose bib and why the pump may not be the root cause.

Symptoms

• Existing in-ground irrigation system with low pressure and incomplete coverage.
• When using a single hose bib with a wand sprinkler, pressure drops to near zero within 2–3 minutes.
• System pressure recovers after pump rests.

Likely Cause: Well Yield Decline

The pump can only deliver water that the well produces. If the water table has dropped—common in drought-prone regions—the well's reservoir depletes quickly. The pump then runs dry, overheats, and shuts off on thermal protection. After resting, the well slowly recovers.

Other Possibilities

• Pressure switch misadjustment: The cut-in/cut-out settings may be too narrow, causing short cycling.
• Failing pressure switch: Erratic operation can mimic well problems.
• Pump wear: Less likely if the pump previously performed well.

Recommended Steps

1. Contact a licensed well driller or pump contractor to measure the well's static water level, drawdown, and recovery rate.
2. Test the pressure switch operation and adjust if needed.
3. Consider deepening the well or drilling a new one if the aquifer has permanently declined.
4. For irrigation, consider a storage tank with a booster pump to decouple demand from well yield.

Addressing the well's capacity is essential; simply replacing the pump will not solve a groundwater supply issue.