Last week the Saudi city of Jeddah was afflicted by heavy rains that lasted only a few hours but caused massive flooding and the deaths of more than 500 people. To lessen the embarrassment, official reports shrank the number of flood-related deaths to just over 100.

Many Saudis are asking how such a catastrophe could occur in one of the world's richest countries and in its second-largest and most cosmopolitan city.

This was the most severe nature-related calamity that the world's largest oil exporter has seen in the past 50 years but the real reason for the death and destruction that occurred last Wednesday is endemic corruption in the Saudi government.

Jeddah is a great example of corruption. This city of more than 4 million people still lacks a sewage system and treatment facility. The rain that fell last week had nowhere to go but to flood the streets and neighbourhoods, creating havoc and death in its path.

Hundreds of bodies were swept in the current and up to 11,000 people may be missing in the sea, according to a report two days ago by the Saudi newspaper al-Yaum. This figure may be inflated but the number of the missing and dead surely ranks in the hundreds, and could turn out to exceed a thousand. For comparison, hurricane Katrina in the US killed about 1,800 people.

The Saudi government reaction to the disaster in Jeddah followed the usual formula of denial followed by blame of the victims for failing to follow government orders. Instead of taking responsibility, a Prince Khalid al-Faisal, the governor of Mecca region, in which Jeddah lies, blamed "arbitrarily built" neighbourhoods, and not the absence of a sewage system. Saudi media, which is mostly owned and fully controlled by the ruling family, followed suit and pointed a finger at citizens who bought land and built houses in unplanned areas.

This has brought to light yet another fact of life in Saudi Arabia: most citizens are unable to buy a home. The percentage of adult Saudis who do not own homes is around 80% – in sharp contrast to other Gulf countries such as Qatar, Kuwait and the UAE, where home ownership rates exceed 80%, thanks to government programmes.

The cause of the low home ownership is the high price of land. This may seem surprising in such a huge country with a relatively small population, but it results from land grabs by members of the ruling family. Many Saudi citizens woke up one day to find that the land they had either inherited or paid good money for has been taken over by a member of the Al Saud. The land deed that the citizen holds becomes worthless and no court will take up the issue. If you complain too much, you will end up in prison.

We Saudis have witnessed massive land seizures across that bare country where fences are erected by princes to enclose hundreds of square kilometres. Jeddah is infamous for land grabs by members of the ruling family – land that is then sold to citizens looking to build a home, without the required planning and infrastructure such as sewage, electricity, water and phone.

King Abdullah has ordered the formation of an investigative committee, headed by the governor of Mecca himself. The committee will not hold any public hearing, or subject members of the "infallible" ruling family to its authority. Let us remember, this is Saudi Arabia, where the Al Saud family are considered above the law. The king's order was received with praise by Saudi media, who referred to his brilliant vision – as is the custom for all of the king's orders, policies, speeches and actions.

The facts, however, paint a very different picture. King Abdullah had ample time and money to meet the development needs for Jeddah and other cities and construct a basic sewage system and other infrastructures for every major city. But it appears that subjects' needs matter very little to an absolute ruler. The people of Saudi Arabia matter very little as well to Arab or international governments who have yet to send condolences or express sympathy for the victims.

Oil was discovered in Saudi Arabia 71 years ago in 1938, but the kings' governments have failed to use oil revenues since then to build a decent infrastructure in Jeddah and other cities. The Al Saud tribe, led by the king, has ruled since 1932 bears all the blame for the disaster in Jeddah and all the government failures for the past 80 years.

No one should blame lazy municipal workers or cheating contractors, or even senior government officials who work under the Al Saud. Simply, we must blame the boss, the big boss. That's where the buck stops.

The state of our country is best exemplified by the Musk Lake, where 1,200 tankers of human waste from Jeddah sewage have been dumped daily for the past 25 years. Naming this chasm of foulness "musk" gives great insight in how Saudi rulers distort the simplest of realities. Musk Lake, not the only lake of human waste in the country, has been the source of diseases such as dengue fever, which has killed dozens and afflicted thousands for years.

At the end of the day, the Saudi absolute monarchy will absolve itself from any responsibility and shortcomings, and its princes will continue live the high life with very little care in the world. May the dead of Jeddah rest in peace and may their families find comfort in each other.