Thousands of Northern California residents were forced to flee their homes over the weekend as the Oroville dam began to flow over the emergency spillway.

Heavy rainfall in recent weeks has caused the Oroville Dam—the nation's tallest—to flow over its emergency spillway for the first time in its history. On Sunday, officials discovered a hole in the spillway, which guards against the dam's overflow when water levels are high, and issued an evacuation order to surrounding cities and counties.

Nearly 188,000 have evacuated already, and Gov. Jerry Brown issued a state emergency order Monday to help local authorities prepare for a worst-case scenario—which could send a 30-foot-wall of water downstream, Cal Fire incident commander Kevin Lawson told CNN.

How can you help those affected by the Oroville Dam evacuations?

To help The Salvation Armyfeed evacuees, make a donation designated "Oroville Response" online, via phone at 800-725-2769 or via mail to the Salvation Army, P.O. Box 348000, Sacramento, CA 95834.

The Red Cross is also opening shelters to help displaced victims; you can make a donation here.

If you're in the area, you can bring supplies to these locations:

• The Elks Lodge in Redding is asking for clothing, cots, sleeping pads, air mattresses, and pet supplies such as crates.
• East Avenue Church in Chico is accepting cots, inflatable beds, sheets, toiletries, bottled water, snacks, first aid kits, diapers, and other items.
• Nevada County Fairgrounds in Grass Valley is asking for snacks and children's clothes, games and other activities.

If you have a place to offer an evacuee or would like to stay in tune with how to help out, keep an eye on this community Facebook page, where people are sharing information, requesting donations, and seeking shelter.