Two feet of rain have battered Hurricane Harvey-stricken Houston, and officials project another 25 inches in coming days. The floods — since downgraded from a hurricane to a tropical storm — will prompt about 450,000 people to seek disaster assistance and put 30,000 in temporary shelters, FEMA Administrator Brock Long said Monday.

“This is a landmark event for Texas,” Long said. “Texas has never seen an event like this.”

Several national and local organizations are aiding in rescue operations and recovery efforts for America’s fourth-largest city. If you aren’t sure where to send your money, here’s a list of vetted groups aiding in relief efforts:

American Red Cross: One of the easiest, most expedient ways to give: Just text HARVEY to 90999 to make a $10 donation. You can also call 1-800-RED-CROSS or visit redcross.org.

“Hundreds of Red Cross volunteers from all over the country are on the ground now, working to provide safe shelter and comfort to people impacted by this devastating storm,” the group said in a statement Sunday. “The Red Cross has enough shelter supplies in Texas to support 28,000 people and supplies for an additional 22,000 people are being sent in now.”

Apple’s iTunes Store also allows you to make a direct donation to the Red Cross in amounts of $5, $10, $25, $50, $100 and $200. Donate through Amazon, and Amazon/Whole Foods will match up to $1 million in cash donations.

Salvation Army: Text STORM to 51555 to donate, call 1-800-SAL-ARMY or visit helpsalvationarmy.org. The group’s Texas arm is providing emergency responders with food and hydration and “preparing for massive feeding efforts for residents.” The Salvation Army has also mobilized its U.S. and Canadian disaster response teams to supplement the effort.

All Hands: A response team from All Hands Volunteers, a disaster relief nonprofit, “has reached Texas and is currently in a staging position in San Antonio.” Donate here.

Save the Children: Give to the group’s Hurricane Harvey Children’s Relief Fund here. Ten percent of your donation goes to Save the Children’s emergency reserve fund.

Portlight: This nonprofit provides disaster relief to people with disabilities. “We’re rallying stakeholders and working together to help get people to safety, and providing for any immediate needs they may have for durable medical equipment and other assistive technology, responding to evacuation and sheltering issues and problem-solving for a variety of immediate disability accessibility issues,” the group announced. Donate here.

Texas Diaper Bank: The organization needs diaper donations and cash to provide displaced families with emergency diaper kits. Give money here.

SPCA of Texas: The animal-welfare group says it’s prepared to take in up to 300 critters affected by Harvey; give money at spca.org/gift. You can also donate to the Houston Humane Society here and to Austin Pets Alive, which is aiding shelters in the direct line of Harvey, over here.

Catholic Charities USA: The U.S. Catholic Church’s official domestic relief agency gives support “before, during and after disasters hit” and emphasizes communities’ “long-term recovery.” Text CCUSADISASTER to 71777 or visit this link.

Local food banks: Chip in some cash to the Galveston County Food Bank here (409-945-4232) and Houston Food Bank here (832-369-9390). Give them a call to ask what they need, the Houston Press recommends.

GoFundMe has also compiled Harvey-related campaigns on a dedicated landing page. Check it out here — the site identifies which charities are certified.

To avoid scams, look up an organization’s details and star rating on the independent evaluation site Charity Navigator, and don’t click suspicious-looking links in emails.