| Scenario | Area (m²) | ET0 | Kc | Eff% | Days | Expected (L) | Suggested min |
|---|---|---|---|---|---|---|---|
| Vegetable beds | 18 | 4.8 | 0.80 | 85 | 7 | 569 | 19 |
| Lawn patch | 35 | 5.5 | 1.00 | 70 | 7 | 1,925 | 28 |
| Drought-tolerant shrubs | 25 | 4.0 | 0.45 | 85 | 7 | 370 | 12 |
Net volume (L) = Net demand × Area × Days × SoilAdj.
Gross target (L) = Net volume ÷ Efficiency.
Applied volume (L) = Flow × Minutes × Cycles × Zones.
Leak flag triggers when Actual exceeds Expected by threshold.
Demand drivers and period planning
Water demand is guided by reference ET0, plant factor, and effective rainfall. Use a consistent tracking window, such as seven or fourteen days, so results remain comparable. When temperatures rise, ET0 typically increases, pushing expected use upward even with unchanged timers. If your garden mixes beds, lawn, and pots, run separate scenarios per zone group to avoid hiding high‑demand areas inside an average.
Efficiency losses and system selection
Efficiency converts net demand into the gross target volume you must apply. Sprays can lose water to wind drift, evaporation, and overspray, while drip systems deliver more water to roots. If you upgrade emitters or fix pressure issues, raise the efficiency value and re-run the estimate. A higher efficiency lowers the required applied volume without changing plant needs.
Soil response and practical adjustments
Soil adjustment reflects storage and infiltration behavior. Sandy soil drains quickly and often performs better with shorter, more frequent cycles. Clay soil stores water longer but can run off if watered too fast, so fewer, deeper cycles are safer. Use soil adjustment to reflect these tendencies, then confirm with simple checks like finger tests, moisture probes, or observing runoff at the end of a cycle.
Flow, runtime, and applied-volume control
Applied volume depends on flow rate, runtime, cycles, and zones. Measure flow at operating pressure using a bucket test or an inline meter. Compare your current runtime to the suggested minutes per event. If the gap is large, adjust gradually in 10–15% steps and re-evaluate after one or two periods. Hybrid mode is useful when you trust both plant demand and your schedule data.
Meter validation and anomaly flags
Meter readings provide a reality check for the same period. When actual use exceeds expected use beyond your chosen threshold, investigate leaks, stuck valves, cracked hoses, or controller faults. Also account for non‑irrigation uses during the window. Export CSV for spreadsheets and PDF for field logs, and keep notes on weather, plant stage, and maintenance to improve future tuning.
FAQs
1) What does “expected use” represent?
It is the estimator’s best total volume for the chosen period. Area mode uses climate demand, flow mode uses your schedule, and hybrid blends both for a balanced expectation.
2) How do I choose an ET0 value?
Use a trusted local reference from a weather source or controller data. If you lack ET0, start with 4–5 mm/day in warm weeks and refine using meter comparisons.
3) Why include effective rainfall?
Not all rainfall benefits roots. Some evaporates or runs off. The factor estimates the portion that soaks into the root zone so demand is not reduced unrealistically.
4) What is a good leak threshold?
Start at 10–20% when irrigation is the main variable. Increase it if household use varies widely, or lower it for more sensitive leak detection.
5) How accurate is suggested minutes per event?
It is a practical starting point based on flow, zones, and cycles. Fine‑tune using soil moisture checks and plant response, then re-run after changes.
6) Can I use this for multiple plant types?
Yes. Run separate scenarios for zones with different plant factors or areas. Compare exports to build a zone-by-zone plan and reduce overwatering.