Startling before and after photographs reveal the devastating floods in Houston as Hurricane Harvey swamps the city and promises to do even more damage with another 50inches of rain this week Hurricane Harvey has left thousands homeless in Houston with more than 5,000 people currently in shelters The number was expected to rise as more rescues were carried out across the Texan city on Monday morning Another 50 inches of rain is set to fall over the coming days which will exasperate the catastrophe Two major dams 20 miles outside of the city are being drained, sending more water cascading into homes Despite the unfolding disaster, the mayor has still not issued a mandatory evacuation order across the city Scores of panicked residents are taking to social media to beg for help after becoming stranded in houses 911 operators are stretched to their limit - on Sunday there was a backlog of 150 calls at any given time Fundraising efforts by the Red Cross are underway and celebrities are donating thousands to relief funds The official death toll is unknown given the chaos which is still unfolding but at least five are feared dead Texas Governor Greg Abbott has deployed the entire National Guard of 12,000 to rescue stranded citizens As Hurricane Harvey ravaged Houston on Monday, the extent of the devastation it has caused started to become clear. Huge swathes of the city now sit underwater as flood water continues to rush through its streets. Thousands are without homes, even more have lost power and 11 people are feared dead across the entire state as a result of the storm. There is no respite on the horizon, with another 50 inches of rain scheduled to land over the course of the week. Many residents have been left no choice but to wait in their homes to be rescued but emergency services have been pushed to the limit. 911 operators are having to choose between life-fearing callers and panicked residents are clambering to their roofs to wave towels in the hope that someone will rescue them.