Why would water be leaking under the driver's side of Chevy Blazer dashboard?

Water leaking under the driver's side of a Chevy Blazer dashboard could be due to a clogged or damaged windshield drain, allowing rainwater to seep into the cabin. Another possibility is a malfunctioning heater core, which can leak coolant into the passenger compartment. Additionally, issues with door seals or gaskets could allow water to enter during heavy rain or car washes. It's important to diagnose the source promptly to prevent electrical damage or mold growth.