Hydrolus
Resource // Screening Tool

Cooling Tower Blowdown Calculator

Estimate makeup demand, blowdown volume, and potentially recoverable water using a simplified cooling-tower water balance.

Operating Inputs
Estimated Daily Water Balance
Estimated Makeup Demand133,333 gal/day
Estimated Blowdown33,333 gal/day
Potential Recovered Water26,667 gal/day
Remaining Liquid Discharge6,667 gal/day
Potential Annual Recovery9,733,333 gal/year

Simplified estimate: makeup = evaporation + blowdown, and blowdown = evaporation / (cycles - 1). Drift, leaks, process losses, treatment losses, seasonal variation, and water-quality limits are excluded.

How to Use the Estimate

Screening Math, Not a Treatment Design.

Use Measured Inputs

Use metered evaporation or a defensible operating estimate and the actual target cycles established for the cooling system.

Check Water Quality

Cycles are constrained by hardness, silica, chlorides, pH, corrosion, treatment chemistry, temperature, and system materials.

Validate the Boundary

Add drift, leaks, treatment losses, seasonal conditions, storage, residuals, and downtime in project-level engineering.

Turn the Estimate Into a Water Balance.

Open the Planning Guide