Thomsons Lake
Perth Region · Western Australia · Reporting period 2023-2024
The verdict
Thomsons Lake's water is clearer than most other localities in the Perth Region.
At a glance
Position within the Perth Region
Purity
By-products & nitrate
About average for the Perth Region
Clarity
Turbidity, colour, metals
Clearer than 69% of Perth Region supplies
Taste
Sodium, chloride, TDS
About average for the Perth Region
Hardness
Calcium & magnesium
About average for the Perth Region
pH balance
How close to neutral (7.0)
About average for the Perth Region
Full readings
Typical (mean) value at Thomsons Lake versus the Perth Region average.
Purity & health
| Parameter | Thomsons Lake | Region avg | Unit |
|---|---|---|---|
| Trihalomethanes (THMs) | 0.06 | 0.07 | mg/L |
Clarity & appearance
| Parameter | Thomsons Lake | Region avg | Unit |
|---|---|---|---|
| Turbidity | 0.20 | 0.28 | NTU |
| Iron | 0.01 | 0.03 | mg/L |
| Manganese | 0.01 | 0.01 | mg/L |
Taste & saltiness
| Parameter | Thomsons Lake | Region avg | Unit |
|---|---|---|---|
| Sodium | 105 | 85.0 | mg/L |
| Chloride | 175 | 142 | mg/L |
| Total Dissolved Solids (TDS) | 431 | 400 | mg/L |
| Sulphate | 20.0 | 19.4 | mg/L |
Hardness & scale
| Parameter | Thomsons Lake | Region avg | Unit |
|---|---|---|---|
| Hardness | 86.0 | 95.7 | mg/L |
| Alkalinity | 74.0 | 83.8 | mg/L |
| Silica | 4.9 | 8.9 | mg/L |
pH balance
| Parameter | Thomsons Lake | Region avg | Unit |
|---|---|---|---|
| pH | 7.8 | 7.8 | pH units |
Compare nearby
All of Perth Region →Suburbs near Thomsons Lake
These suburbs aren't individually tested — Thomsons Lake is their closest monitored supply point.
Data & methodology
Data source: Water Corporation of WA Drinking Water Quality Annual Report 2023-2024.
Regional ranking: Each measured parameter is ranked against every other locality in the Perth Region using the typical (mean) reading. Lower readings rank better, except pH where the score is distance from neutral (7).
ADWG safety check: Every reading is independently checked against the NHMRC Australian Drinking Water Guidelines; any value above the limit is flagged regardless of how it compares to neighbours.