Hurricane Harvey continues to pommel southeastern Texas with federal emergency chief Brock Long saying approximately 30,000 people are going to be in temporary shelters due to flooding.

“This is a landmark event for Texas...I’m asking for all citizens to get involved here," Mr Brock said.

The rain is expected to continue for at least three to four more days and flooding is expected to get worse as dams in the Houston area will have to be released to relieve pressure on them.

Below are some ways that you can help. But, before giving to any organisation it is best to do a bit of research into how your donation will be used. A good place to look is Charity Navigator. The website also suggests only donating through official group websites and not via unverified social media channels.

Give cash not goods

As aid organisations have geared up to help those in need, an influx of material goods may be more of a hindrance than a help as transportation and logistics are difficulties in disaster zones. Cash donations also allow more flexibility to fill unique needs for various communities.

A simple way to donate is using your mobile. You can text UWFLOOD to 41444 to donate to the United Way Flood Relief Fund or CCUSADISASTER to 71777 for donations to the Catholic Charities USA.

The American Red Cross has been repeatedly criticised for its ineffective response during previous natural disasters, like Hurricane Sandy, but they are a large charity supporting several local shelters and relief efforts. You can text the word HARVEY to 90999 to make a $10 donation.

The Salvation Army's Hurricane Harvey relief efforts can be made at helpsalvationarmy.org or by calling 1-800-SAL-ARMY.

Give to local charities

While there are several large, national charities set to help, groups with local ties to a community may be in a better position to help victims.

All Hands already has staff and volunteers on the ground who are in contact with emergency management personnel.

Humane Societies in San Antonio and Houston as well as the Society for the Prevention of Cruelty to Animals of Texas are all working to provide shelter and care to pets in the affected region.

Medical supplies will likely be in high demand as more and more are rescued from flooded areas and power outages are affecting hospitals. Americares and Heart to Heart International provides help to first responders and other medical professionals for emergency care.

Portlight is an organisation dedicated to assisting people with disabilities who may not have been able to evacuate or have special medical or suitable shelter needs during the disaster.

International Relief Teams provide personal hygiene kits to disaster victims.

The Texas Diaper Bank is set to help families as well.

One of the more terrifying aspects of natural disasters like Hurricane Harvey is what happens to homeless people. While specific homeless shelters will need donations, there is an umbrella organisation that can help coordinate needs called Coalition for the Homeless.

Donate to food banks

One exception to the cash donation preference may be local food banks, particularly if you are located nearby. Texas can activate a federal government programme to help residents with emergency relief.

Houston Press has put together a list of food banks in the areas affected, but disaster relief experts advise calling them before making a donation about how best to help.

Non-perishable, packaged items and cleaning supplies are usually preferred.

Use your language Skills

The Houston area in particular may be in need of translators and interpreters since it is home to the largest number of refugees in the US as well as a large population of immigrants.

Spanish, Vietnamese, Arabic, and American Sign language skills could be of use to relief organisations, hospitals, radio stations, other local media outlets, and first responders - paramedics, police, fire departments. It is best to call officials and groups in the area first to determine need.

Donate blood

If you're in the region or looking to give a cash donation, the South Texas Blood and Tissue Center is looking for help as rescue efforts are underway and local hospitals take in new patients.

Donate shelter

AirBnb, the website which allows people to book stays in other people's homes while on holiday or other trip, is waiving fees for those needing shelter and has a link for people in safe areas to offer space in their homes.

Longer-term donations

After a disaster of this magnitude it will take a significant amount of time for those affected to rebuild their homes and lives. Setting up recurring donations to any of these groups will also help in longer term recovery efforts.

Many of those most deeply affected by Hurricane Harvey are likely the poorer communities along the Texas coast and in Houston. Some have lost their homes and livelihoods as a result of the storm.

Habitat for Humanity is an organisation that helped rebuild homes after Hurricane Katrina in 2005 and may be helping in Texas recovery efforts in the near future.