Detailed Answer
Atmospheric rivers are Sacramento's most significant gutter stress event. A single AR can deliver more rainfall in 24 hours than Sacramento receives in the first two months of winter. Gutters that are partially blocked, sagging, or discharging too close to the foundation are routinely responsible for foundation flooding, fascia damage, and landscape erosion during these events.
Preparation starts with a thorough cleaning 1–2 weeks before the forecast arrival window. Clearing all leaves, debris, and partial downspout blockages before peak rain arrival ensures the full capacity of the system is available when it matters. Don't wait until the day before — saturated debris and waterlogged conditions make last-minute cleaning messy and incomplete.
After cleaning, flush each downspout with a garden hose. The water should flow freely and exit at full pressure at the discharge point. If it backs up or drains slowly, there's a blockage in the underground portion or at the elbow connection that needs to be cleared before the storm arrives.
Check downspout extensions and discharge locations. Downspouts that terminate at the foundation or within 18 inches of the house are a foundation risk during high-volume events. Extend them with adjustable elbow extensions to discharge at least 4–6 feet from the foundation — 8–10 feet if your yard slopes back toward the house or if you have Sacramento's clay-heavy soil that doesn't absorb water quickly.
Inspect gutter hangers and any sections that appeared slightly low or pulling away from the fascia. Loose hangers fail under the weight of water-filled debris during heavy rain. Replacing a hanger is a $20 job before the storm; a gutter section ripping off the fascia mid-storm is a much larger repair.