The following links were obtained and provided by one Ryan Underhill. Some of these links are lists themselves, and there may be some duplication of charities or services, but he strove to be as thorough as possible, and he's adding to the list all the time. I'm not taking the time to vet it and remove duplicates; I don't have the time, and neither does he.
He nor I claim this to be a fully comprehensive list, but the best he could come up with in a pinch.
Of course, if you don't recognize a charity, be wary. Con artists come out of the woodwork when people are emotionally weakened after a disaster.
I'll try to add more to it as he updates the FB thread located here: Extensive List, Many More In The Comments
NEW - Louisiana Flood Relief - $345 of $10k goal
NEW - 2016 Louisiana Flood Relief Donations
Assistance/Relief for flood victims
If your fireplace was impacted or gas logs were impacted by the recent floods, complete the form
How to apply for help with flood damage when you don't have flood insurance
Suspension of Insurance Provisions in Flood Affected Parishes
NOLA Pay It Forward Fund: Helping Families in Neighboring Parishes
Did you flood? Do you want to help? Here's what you need to know
Louisiana flood: How to help schools
LSART - the Louisiana State Animal Response Team
Managing Collections After a Disaster, like stamps, comics, etc.
DCFS announces locations to apply for disaster food stamps
Have horse experience? Volunteers needed at Lamar Dixon shelter
How to document damage for FEMA claim
How To Help Louisiana Flood Victims
New Orleans Public Library hosts food drive for flood victims, plus more donation drop points
How to get help after flood damage in Louisiana
AMAZING DONATIONS TO MAKE RIGHT NOW
10 Things You CAN DO for Flood Victims
Helping Flood Victims in Southeast Louisiana
If you own your home (that is not a trailer), do NOT have flood insurance, and are in need of assistance gutting and cleaning, please fill out the following form and email it to firstname.lastname@example.org (email@example.com)
Companion Animal Alliance’s shelter on Progress Road
A Distress Call to every American, from every Louisianan
Disaster Recovery and Relief, Emergency Disaster Information for Louisiana Residents
State opens preregistration for disaster food stamps
PLEASE HELP THE PETS DISPLACED BY THE FLOODS!
Early Prescription Refills Available to Most Members
Good Times for a Good Cause: A List of Louisiana Flood Relief Shows
How to revive a flooded lawn
Take 5 Oil Change is still collecting new supplies and monetary donations, Aug 16-23. Check if they've extended the dates.
Office of the Governor, Resources for Flood Victims
Direct gutting and rebuilding services as well as provide technical support, capacity building and best practices to other recovery orgs
Hygienic items of all kinds, pet supplies, gift cards
Saints announce raffle to support flood relief efforts
Personal page, looking for help
Springfield Flood Relief Center
New Orleans Area Habitat for Humanity
Governor announces plans for temporary housing
Sunday, August 28th for Rock for Relief and help us support Baton Rouge flood relief!!
Gut your sheet rock and spray to kill the mold for free
Transitional Housing vs. FEMA Housing
Chase donates $200k to flood efforts, waives fees through August
Little Pnuts & Little Pnuts Toy Shoppe collecting toys, games, books and other childrens items for Louisiana flood victims.
DOTD establishes temporary bus service to Baton Rouge
How to rescue a garden after flooding and excessive rain
SCAM WARNING FROM FEMA, regarding "mold free certificates".
Communities In Schools of Greater New Orleans
Damage assessment and recovery from flooding.
Austin companies pitching in to help Louisiana flood victims
Rescued cats housed in Jefferson Parish need homes
Realty Point Opens Its Doors To Donations In Response To LA Flooding
Walton County Sheriff, Michael A. Adkinson, Jr.
Resource page for our nonprofit organizations
How to Help: Volunteering, make donations, debris removal
Flood Relief Resources Available for La. Cultural Institutions and Artists
How to help Louisiana flood victims
Helpful Answers to Flood Related Questions
Dependable In Home Care
Baton Rouge Disaster Relief
If you need help cleaning up your home, call this number. #laflood