| Business | Phone |
| Colusa Ambulance 1259 Market St, Colusa 95932 | (530) 458-7414 |
| Colusa Building Inspector 750 Market St, Colusa 95932 | (530) 458-4740 |
| Colusa Water-Sewer Dept 840 Main St, Colusa 95932 | (530) 458-4266 |
| Corporation Yard 12th & Mainamp;, Colusa 95932 | (530) 458-2215 |