The drastic fall in oil prices over the past few months might be bringing smiles on motorists' faces, but it is really painful for Houston's oil industry.

On December 11, which Houston oil business leaders assembled at the Omni Hotel near downtown for a yearend chamber of commerce luncheon, price of oil was $45 less per barrel than where it was in July - the last time when oil prices were over $100 a barrel.

Patrick Jankowski, a resident research economist at the Greater Houston Partnership, said, "We're entering a period where oil won't be the primary driver in Houston's economy."

Houston, which has more oil companies than any other city of the world, is heavily dependent on oil revenue. With estimated value of more than $500 billion, Houston economy is the fourth-biggest in the entire United States.

The city added as many as 628,000 jobs over the past decade. In other words, the city added more jobs than total existed jobs in all of New Orleans. Most of the new jobs were created by the city's oil industry. In August this year, more new permits were issued in the city than in the rest of California.

The above mentioned facts are enough to gauge the importance of oil industry in Houston's local economy. The city's heavy dependence on oil industry is also enough to justify its worries about falling prices.

By the end of that day of luncheon, oil had slipped below $60 a barrel, the lowest since 2009. At $60 a barrel, companies producing oil in Texas collectively witnessed their monthly cash flow falling from $6.4 billion in June to $3.6 billion in December.