| Flood Impacts |
| 33.0 Feet | Disastrous flooding of all areas near the river from Blue Lake to the mouth. The river is forecast to exceed record levels. All roads in the vicinity of the river are likely to be innundated and travel will be severly restricted. Residents should be prepared to take appropriate action to protect lives and property. This would include homes in Blue Lake, Tyee City and the Arcata Bottoms, as well as US Highway 101 between Arcata and Mckinleyville. |
| 32.0 Feet | Disastrous flooding of all areas near the river from Blue Lake to the mouth. The river is forecast to approach record levels. All roads in the vicinity of the river are likely to be innundated and travel will be severly restricted. Residents should be prepared to take appropriate action to protect lives and property. This would include homes in Blue Lake, Tyee City and the Arcata Bottoms, as well as US Highway 101 between Arcata and Mckinleyville. |
| 30.0 Feet | Extensive, severe flooding of all low lying areas near the river from Blue Lake downstream to the mouth. Residents in these areas should be prepared to take appropriate action to protect lives and property. Critical locations include residential areas of Blue Lake, Tyee City, and the Arcata Bottoms, as well as US Highway 101 near Janes Road and areas near Giuntoli Lane. |
| 28.0 Feet | Severe flooding of all low lying areas near the river from Blue Lake downstream to the mouth. Residents in these areas should be prepared to take appropriate action to protect lives and property. This includes residential areas of Tyee City and the Arcata Bottoms, US Highway 101 near Janes Road, areas near Giuntoli Lane, and Mad River Beach Road. |
| 26.0 Feet | Severe flooding along Mad River Beach Road and extensive flooding of farmlands and other roads in the area. Flooding of residential areas around Tyee City is likely. Any low lying areas near the river could be flooded. Residents in these areas should be prepared to take appropriate action to protect lives and property. |
| 24.0 Feet | Extensive flooding along Mad River Beach Road and adjacent farmlands. Some homes along the river could be threatened. Flooding of roads to Tyee City. High tides and strong onshore winds will enhance flood impacts. |
| 23.0 Feet | Significant flooding of portions of Mad River Beach Road and adjacent farmlands is likely. May cause water to flow across roads to Tyee City. High tides and strong, onshore winds will aggravate flood impacts. |
| 22.0 Feet | Significant flooding of portions of Mad River Beach Road. Water may flow across roads to Tyee City. Flood impacts will be aggravated by high tides and strong, onshore winds. |
| 21.0 Feet | Flooding of Mad River Beach Road. Water may be flowing over roads to Tyee City. Flooding will be enhanced if the time of the crest is coincident with high tides and strong onshore winds. |
| 18.0 Feet | Minor flooding of Mad River Beach Road near Tyee City. |
| 15.0 Feet | Minor flooding begins on the Mad River Beach Road near Tyee City. |
