Well Yield & Recovery Rate: What They Mean
📋 In This Guide
Definitions
Well Yield
- Amount of water well can produce sustainably
- Measured in gallons per minute (GPM)
- May also see gallons per hour (GPH) or per day
- Depends on aquifer productivity
Recovery Rate
- How fast water level recovers after pumping
- Related to how quickly aquifer recharges well
- May differ from sustained yield
Drawdown
- How much water level drops during pumping
- Measured in feet
- More drawdown = pump working harder
Static Water Level
- Water level when NOT pumping
- Starting point for drawdown measurement
- Changes seasonally
Example
Well with 50 ft static level, 80 ft drawdown level at 10 GPM:
- Drawdown = 30 feet
- Yield at that rate = 10 GPM
- Recovery = how fast it returns to 50 ft
How It's Measured
Pump Test / Yield Test
- Measure static water level
- Pump at steady rate
- Monitor water level during pumping
- Continue until level stabilizes (or for set time)
- Record GPM at that drawdown
- Stop pumping, measure recovery
Test Duration
- Short test (1-4 hours): general indication
- Standard test (4-8 hours): good for residential
- Extended test (24-72 hours): aquifer characterization
Cost
Yield testing: $200-$500 depending on duration and detail
When to Test
- Buying property with existing well
- After new well drilled
- If yield seems to be dropping
- Before adding water demand (irrigation, pool)
What's Adequate?
Residential Guidelines
| GPM | Rating | Suitable For |
|---|---|---|
| 0.5-2 | Very low | Cabin, with storage tank |
| 3-5 | Low | Small home, careful use |
| 5-8 | Adequate | Typical home |
| 8-12 | Good | Family of 4+, some irrigation |
| 15+ | Excellent | Large home, irrigation |
Why 5 GPM Minimum?
- Shower: 2-2.5 GPM
- Dishwasher: 1.5-2 GPM
- Washing machine: 2-4 GPM
- 5 GPM handles one major fixture at a time
- Lower yields need storage to buffer demand
Calculating Your Needs
- Basic rule: 100-150 gallons per person per day
- Family of 4: 400-600 gallons/day
- Irrigation: add significantly (varies)
- Livestock: 10-50 gallons/day per animal
Low Yield Issues
Causes of Low Yield
- Geology: Tight formations, low-productivity aquifer
- Depth: May not be reaching good water-bearing zone
- Well condition: Clogged screen, biofouling
- Seasonal: Water table drops in dry season
- Regional: Aquifer depletion from many wells
Declining Yield Over Time
If yield was good but dropping:
- Well screen clogging (minerals, bacteria)
- Pump positioned wrong (too shallow)
- Aquifer changes
- Well may need rehabilitation
Seasonal Variation
- Normal for yield to vary with seasons
- Lower in late summer/fall (dry season)
- Higher in spring after rains
- Plan usage around minimum yield
Improving Yield
Storage Tanks
- Even low-yield wells produce water 24/7
- 1 GPM = 1,440 gallons/day
- Storage tank collects water during low use
- Provides reserve for peak demand
- Cost: $1,500-$5,000+ depending on size
Well Rehabilitation
- Chemical treatment to clear deposits
- Mechanical cleaning
- May restore lost yield
- Cost: $1,500-$5,000
Hydrofracturing
- High-pressure water opens fractures
- Can improve yield in fractured rock
- Success varies—not guaranteed
- Cost: $1,500-$3,000
Deepening Well
- May reach better water-bearing zones
- Not always successful
- Cost: $2,000-$10,000+
New Well
- Different location may find better source
- Hydrogeologist can help site selection
- Cost: $15,000-$50,000+
Sizing Pump to Yield
Don't pump faster than well produces:
- Oversized pump can damage well
- Draws water level down too far
- Pump may run dry
- Match pump GPM to sustainable yield
We service all major pump brands including Franklin Electric, Grundfos, Goulds (Xylem), and Sta-Rite (Pentair). Our trucks carry common parts and components for same-day repairs.
Frequently Asked Questions
What is a good yield for a residential well?
5 GPM is minimum adequate. 8-10 GPM is comfortable for a family. Low-yield wells (1-3 GPM) can work with storage tanks.
What's the difference between yield and recovery?
Yield is sustainable pumping rate (GPM). Recovery is how fast water level returns after pumping. Both matter for system design.
Can I improve my well's yield?
Sometimes. Options: rehabilitation, hydrofracturing, deepening, or storage tank to work with low yield. Success varies by situation.
Why has my yield dropped?
Could be clogged screen (fixable), seasonal variation (normal), or aquifer changes. Yield test and well inspection can diagnose.
How is yield measured?
Pump test: run pump at steady rate while measuring water level. Note GPM when level stabilizes. Professional testing costs $200-$500.
Concerned About Yield?
We perform yield tests and can advise on solutions for low-producing wells.
Related Articles
Continue learning about well maintenance and troubleshooting
