Greenhouse Rainwater Collection Calculator.
Estimate captured rainwater, demand coverage and the basin needed to carry it through the dry season.
Greenhouse Rainwater Collection Calculator
Estimate captured rainwater, demand coverage and the basin needed to carry it through the dry season.
Estimate only — not a quotation. Outputs are indicative planning ranges based on the values you enter and typical commercial benchmarks. Real pricing, specifications and lead times vary by country, site conditions and supplier, and are confirmed only in written offers collected through a private RFQ.
Project inputs
Loss from gutters, splash and first flush.
Planning values only, not an engineering design or a quotation. Final sizing requires the supplier's or engineer's own calculation for the site.
Send these numbers to the RFQ Builder
The numbers below were calculated with SeedMatchGroup's Greenhouse Rainwater Collection Calculator. Indicative — the specialist will confirm scope before contacting suppliers.
9 inputs · assumptions · results
Turn this estimate into a qualified project
SeedMatchGroup is a supplier-neutral, human-led platform. We do not manufacture or resell equipment — we help buyers specify the project, review relevant suppliers privately and compare the written offers received. Supplier participation and timing are not guaranteed.
Method and assumptions
Captured volume = roof area × rainfall × runoff coefficient. Storage = the smaller of annual capture or average monthly demand × dry months — you cannot usefully store more than you collect.
Limitations: Uses annual totals. Rainfall timing, intense storms overflowing gutters and evaporation from open basins need monthly data and a water balance before design.
Worked example
5 ha of roof with 600 mm rain and 85% runoff captures ~25,500 m³/yr — about 43% of a 60,000 m³ demand — and a 4-month dry season calls for ~20,000 m³ of storage.
Frequently asked questions
Related tools: water storage calculator · water consumption calculator · integrated project designer
Understanding the values
What each choice in this calculator means, and how the options differ in practice.
- Peak vs average demand
- Hydraulic design follows peak daily demand. Sizing on averages leaves the crop short exactly when stress costs the most yield.
- Efficiency assumptions
- Emitter, filtration and distribution losses compound. A few points of efficiency at each step add up to a large difference at the pump.
Illustrative project summary
1 ha multi-span tomato house
A new commercial entrant builds a first multi-span block with fertigation, insect screens and a basic climate computer.
1 ha · Multi-span polyhouse · Tomatoes
Indicative full greenhouse project CAPEX
USD 575K – USD 1.56M
Illustration only, not a real project or quotation. This is the structure, equipment and site-works budget for the example greenhouse, not the price of this calculator’s individual system, seeds or inputs, and not a result calculated from your entries. Excludes land, permits, packhouse, financing costs and working capital.
Based on the published commercial greenhouse cost benchmark. Written offers require a private project review; commercial projects start from USD 250K.
What can change the result?
This is a preliminary planning estimate based on the values you entered. The variables below usually move the outcome most, and should be confirmed with an agronomist, engineer and supplier offers before final design.
- Crop and cultivar — water, climate and support requirements differ per crop
- Local climate: temperature, humidity, radiation and wind exposure
- Irrigation design, emitter spacing and application efficiency
- Water quality and treatment needs (EC, pH, iron, hardness, pathogens)
Questions this calculator answers
Typical buyer and investor searches this tool is built for, including the markets where we run the most commercial projects.
- greenhouse water requirement and storage sizing per hectare for a commercial project
- greenhouse water requirement and storage sizing for a 2-hectare project — India
- greenhouse water requirement and storage sizing: indicative planning ranges — Kenya
- greenhouse water requirement and storage sizing benchmarks for investors — Saudi Arabia
- greenhouse water requirement and storage sizing under local market conditions — Mexico
- greenhouse water requirement and storage sizing — what to specify in a supplier RFQ
Method and decision path
How to use this result in a commercial project
Use the result to test scope and compare scenarios. It is not a design, agronomic prescription, financing offer or supplier quotation.
1. Enter site evidence
Replace defaults with measured area, climate, water, energy, crop and commercial assumptions.
2. Test scenarios
Change one assumption at a time and record the effect on capacity, cost, demand or return.
3. Validate the duty
Ask the relevant agronomist, engineer or financial adviser to check the inputs and constraints.
4. Prepare a private RFQ
Carry the confirmed scope into a human-reviewed brief so written offers can be compared on the same basis.
Final specifications, performance, prices, supplier participation and timing depend on the site and written supplier responses; none is guaranteed by this calculator.
Plan the project around the numbers
A calculator output is a starting point. Pair it with the planning guides below to align timeline, irrigation, budget and risk before you launch an RFQ.
One private brief, specialist review, private supplier research and a like-for-like comparison.
Month-by-month schedule from concept to first harvest across 9 stages.
Design principles for drip, pivot, fertigation and filtration on commercial projects.
How CAPEX, working capital and operating cost drive the project business case.
The ten most expensive planning and procurement pitfalls — and how to avoid them.
Procurement answers behind these numbers
A model output only holds if the scope, contract route and delivery terms match the assumptions. These reference answers cover the commercial decisions that move the figure.
- Turnkey EPC vs separate equipment packages
- What belongs in a greenhouse equipment specification
- Normal payment milestones in equipment contracts
- Which Incoterms to use for greenhouse and irrigation equipment
- How long a commercial greenhouse takes from order to handover
- What is normally the owner's scope on a greenhouse project
Move greenhouse rainwater collection calculator into a structured RFQ
Editorial · not a sales pitchCalculator outputs are indicative. When your numbers stabilise, a supplier-neutral RFQ turns those estimates into a consistent brief for comparing the written offers that participating suppliers provide.
The facts a complete, supplier-neutral request on this topic includes. Use it as a checklist before submitting.
- Irrigated area, block layout and topography/elevation change
- Crop, spacing and peak daily water requirement (mm/day or m³/day)
- Water source (borehole, canal, reservoir, municipal) with yield and analysis
- System type: drip, sprinkler, pivot, micro-sprinkler, fertigation
- Required flow (m³/h), pressure and number of zones/shifts
- Power availability: grid, generator or solar pumping
- Automation and control level required
- Water analysis report and borehole test results
- Field/plot map with dimensions and elevation
Opens the RFQ Builder scoped as an irrigation package so suppliers quote hydraulics, filtration and dosing consistently. You stay in control — nothing is submitted until you review and confirm.
Free to submit · supplier-neutral · reviewed by a specialist before any supplier is contacted.
Running these numbers for a client project?
Agronomists, greenhouse and irrigation consultants use this calculator for feasibility, then hand the project to us for supplier shortlisting, RFQ preparation and quote comparison. You stay client-facing and we work through you.
Your client relationship stays with you — we work through you and never contact your client unless you ask.
Indicative only
- This tool is indicative only.
- It is not financial advice.
- It is not agronomic advice.
- It is not engineering design.
- Final numbers require supplier, agronomist, engineer and local regulatory review.
SeedMatch Group is an independent agricultural project sourcing and RFQ platform. We are not a farm, seed producer, fertilizer manufacturer, irrigation manufacturer, greenhouse builder, EPC contractor, lender or financial advisor. Supplier and project partner outreach is handled only after a commercial project brief is reviewed.
Supplier and manufacturer listings are provided for research, transparency and discovery only. SeedMatch Group does not provide automatic buyer-supplier introductions. Every agriculture project request is reviewed manually by the SeedMatch project team, and supplier introductions are made only after internal approval.