Rainwater planning

Rainwater planning tools

Twelve working calculators for roof yield, tank sizing, water balance, garden demand, gutters, filtration, overflow, costs and options.

Calculate annual roof yield, demand coverage, overflow and shortfall with a monthly storage balance.

See monthly inflow, use, tank level, overflow and shortfall for a selected rainfall profile.

Compare many capacities and find the smallest tank that reaches the selected demand coverage.

Calculate water yield from horizontal roof projection, rainfall, roof material and system efficiency.

Estimate monthly plant demand from area, reference evapotranspiration, plant factor, rainfall and irrigation efficiency.

Estimate peak roof runoff during rain and compare it with the declared combined downpipe capacity.

Calculate first-flush volume, water loss and minimum filter flow with an adjustable safety factor.

Check how much water from a single storm fits in the tank and how much reaches overflow or infiltration.

Add tank, pump, filter and installation costs, then calculate annual savings and simple payback.

Estimate non-potable demand for toilet flushing, cleaning, washing and other uses from your own assumptions.

Open, rename, duplicate, delete, export and import locally saved rainwater system options.

Compare two saved projects by yield, demand coverage, overflow, shortfall, capacity and cost.