Arena Watering System Design: 150'×250' with 2500-Gallon Tank

Designing a fast-cycle arena sprinkler system for horse shows requires high-flow rotors, proper zoning, and pump sizing to empty a 2500-gallon tank in 15-minute breaks. Here's a practical layout for a $5,000 budget.

Hydraulic Reality Check

• 8 heads × 75-ft throw = Hunter I-40 rotors at 100 PSI, ~30 GPM each
• 2 heads per zone = 60 GPM per zone
• 4 zones × 5 min = 20 min cycle (exceeds 15-min window)
• 60 GPM × 20 min = 1,200 gallons per cycle
• Two cycles = 2,400 gallons (near tank capacity)

Recommended Compromises

1. Reduce to 6 heads (3 per side), 3 zones × 2 heads = 5 min each = 15 min total.
2. Accept 80% coverage—adequate for dust control, not full saturation.
3. Pump: 2" suction/discharge, 110–120 PSI at 60 GPM (e.g., Berkeley B2ZRM or equivalent).
4. Piping: 2" PVC mainline, 1.5" laterals to valves.
5. Valves: 1.5" electric valves (Rain Bird PEB or Hunter ICV).
6. Controller: 4-station battery timer or basic AC controller.

Budget Allocation (~$5,000)

• Pump: $1,200–$1,800
• 6 rotors + nozzles: $600
• 3 valves + box: $450
• 2" PVC pipe/fittings: $800
• Wire, controller, misc: $500
• Labor (DIY saves $1,500+)

Critical Design Notes

• Tank must refill between shows—verify well/flow rate.
• Install foot valve and priming chamber on pump.
• Use schedule 40 PVC; pressure-rated fittings.
• Include pressure gauge and drain valve at pump.
• Consider a VFD pump for softer start/pressure regulation.

DIY Feasibility

Experienced DIYer can trench, glue pipe, wire valves, and set pump in 2–3 weekends. Rent a trencher. Hire electrician for pump power if 220 V. Permit may be required—check local codes.