How to Use a Water Audit to Identify Major Savings in Commercial Buildings
As water costs rise and sustainability standards tighten, more commercial building owners are taking a closer look at their water consumption. A water audit is the critical first step. It provides a detailed breakdown of where water is used, how much is lost or wasted, and most importantly—where it can be reused or offset.
A proper audit doesn’t just reveal inefficiencies. It uncovers powerful opportunities for water harvesting retrofits that can reduce dependence on municipal water while saving thousands in utility costs.
What Is a Water Audit?
A commercial water audit is a structured evaluation of all the water entering, moving through, and exiting a building. It typically includes:
- Utility bill analysis to determine baseline consumption and seasonal variation
- Equipment inspection to evaluate plumbing fixtures, cooling systems, and process water use
- Site walkthrough to identify leaks, inefficient practices, and potential harvesting sources
- Water balance modeling to compare inputs (municipal, harvested, groundwater) with outputs (cooling tower, irrigation, sewer discharge)
The result is a data-driven strategy for improving water efficiency—often with a strong financial ROI.
Categories of Water Savings to Explore
During a water audit, every system that consumes water should be reviewed. The most common categories for potential savings include:
1. Cooling Towers
Cooling towers are among the largest water consumers in commercial buildings. A typical system can lose thousands of gallons per day through evaporation and blowdown. Evaluating your Cycles of Concentration (COC), blowdown volume, and water chemistry can reveal major savings opportunities through water recycling or improved control strategies.
2. Irrigation Systems
Outdoor landscaping is another key opportunity. Many systems are set to run on timers instead of soil moisture levels and overwater plants by 30–50%. Audits can help evaluate:
- Planting types and soil permeability
- Irrigation scheduling and controller types
- Potential for non-potable water use like rainwater or groundwater
3. Indoor Fixtures
Restrooms, kitchens, and janitorial sinks often use outdated or oversized fixtures. Replacing these with low-flow or high-efficiency versions can reduce indoor water consumption by up to 30%.
4. Process Water and Specialty Uses
Facilities like food production, labs, or data centers may have significant process water use. Identifying ways to clean and reuse that water can significantly lower discharge costs.
Evaluating Water Harvesting Retrofit Potential
Beyond cutting water use, a growing number of buildings are exploring on-site water harvesting systems. The key is to identify where supply and demand overlap.
A. Water Supply Sources to Consider
- Groundwater: Often viewed as a nuisance when it seeps into basements or sump pits, groundwater can be continuously captured and reused for non-potable needs. Wahaso systems are designed to treat this water—even when it contains hardness, silica, or heavy metals.
- Rainwater Harvesting: Ideal for buildings with large roof areas and moderate rainfall. Collected water is low in minerals and well-suited for irrigation and indoor non-potable uses like toilet flushing.
- Condensate: Mechanical systems such as air handling units and rooftop RTUs produce a steady stream of condensate, especially in warm, humid climates. This ultra-clean water source is ideal for cooling tower make-up or irrigation.
- Stormwater: With proper filtration and settling, stormwater harvesting can be a powerful tool to meet both water reuse and stormwater management requirements. It’s especially valuable in urban areas with green infrastructure mandates.
B. Water Demand Targets for Reuse
- Cooling Tower Make-Up Water: Using harvested water to supply your cooling tower is one of the most efficient uses. It reduces reliance on municipal water, cuts blowdown, and may eliminate sewer discharge costs.
- Landscape Irrigation: Rainwater, stormwater, and condensate are ideal for outdoor irrigation—allowing facilities to stay green even during drought restrictions or water bans.
The Power of Wahaso’s CT Recovery System
One of the most overlooked opportunities for water savings is in cooling tower blowdown recovery. Wahaso’s CT Recovery System captures the high-volume blowdown stream and treats it using a modified ultra-filtration (MUF) process. This treated water is returned to the tower or reused in other applications, reducing make-up demand and sewer discharge.
Want to know if your facility is a good candidate?
Use Wahaso’s Cooling Tower Water Savings Calculator to estimate your potential recovery based on your current system size, COC, and water chemistry. Buildings with low COCs (2–3) and hard water are often ideal for CT recovery, since more blowdown is generated and more savings can be achieved.
Start with a Water Audit — We’ll Help You from There
If you haven’t conducted a recent water audit at your facility, now is the time. Whether your goal is cost savings, LEED certification, or municipal compliance, Wahaso can help identify which water harvesting strategies make the most sense—and deliver the most value.
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Our mission at Wahaso is to help municipalities and commercial property owners reduce the impact of their buildings on the environment through innovative and sustainable water practices.
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