Main Street Capital (NYSE: MAIN) operates out of the eighth floor of an otherwise nondescript building in Houston, Texas. As a small-business financier that provides debt and equity financing to companies in the surrounding areas, many of its portfolio companies are in its own backyard. I calculate that approximately $89 million of its investments, which amount to 7.2% of the company's last reported book value, are in companies with headquarters or operations in Houston and the surrounding areas that have been hard hit by Harvey. Company Headquarters Fair Value (in Thousands of Dollars) American Shooting Centers Houston, TX $4,320 BBB Tank Services Baytown, TX $5,591 GMI Group Humble, TX $11,247 Gulf Publishing Company Houston, TX $17,022 Harrison Hydra-Gen Houston, TX $2,800 Hawthorne Global Houston, TX $2,320 Houston Plating & Coatings Houston, TX $7,980 PPL RVs Houston, TX $29,780 River Aggregates Conroe, TX $7,586 Rocaceia Energy Services Victoria, TX $250 Total $88,896 Data source: Company filings, Main Street Capital IR, company websites. Chart by author. At this point in time, it's still too early to know just how much Harvey will impact the local economy and how these impacts will flow through to Main Street Capital's own profit and loss statement. BBB Tank Services, which provides "maintenance, repair, and construction services to the above-ground storage tank market" is likely to be particularly busy as Houston recovers from Harvey. On the other hand, a trip to American Shooting Centers' gun range is an unlikely priority for people dealing with flooding in their homes and workplaces. Image source: Main Street Capital. Descriptions of each company appear in Main Street Capital's quarterly filings and are reproduced below. Company Description American Shooting Centers Recreational and educational shooting facility BBB Tank Services Maintenance, repair and construction services to the above-ground storage tank market GMI Group Manufacturer of specialty fabricated industrial piping products Gulf Publishing Company Energy industry-focused media and publishing Harrison Hydra-Gen Manufacturer of hydraulic generators Hawthorne Global Facilitator of import logistics, brokerage, and warehousing Houston Plating & Coatings Provider of plating and industrial coating services PPL RVs Recreational vehicle dealer River Aggregates Processor of construction aggregates Rocaceia Energy Services Provider of rigsite accommodation unit rentals and related services Data source: Main Street Capital's most recent 10-Q filing. Chart by author. PPL RVs -- by far Main Street Capital's biggest exposure -- notified its customers via Facebook that there is "no damage at PPL to the building or any of the units. However, there is also no way to get onto the lot. It's an island. We will know more [Monday] morning about opening and keep everyone updated." The company was closed on Monday because of Hurricane Harvey, according to its website. PPL RVs is a recreational vehicle dealer that sells RVs on consignment, which is at least 50% owned by Main Street Capital, according to a presentation at its annual meeting. Quantifying the impact The Dallas Morning News summed up the potential losses from Harvey succinctly. Southeast Texas has at least $400 billion of residential property at risk from flood waters. The publication wrote the following in a blog post: Harvey is likely to be one of the most expensive storms ever. Based on Census 2015 data (most recent available), the value of residential property in the eight counties of the Houston metro area exceeds $353 billion. The coastal counties from Beaumont to Corpus Christi add an additional $39 billion in residential value. This brings the value of residential property alone that is at risk from this storm to nearly $400 billion. The number grows when you consider the property within those structures, commercial property, and vehicles. Disasters have knock-on effects that go far beyond damaged property -- from job losses to displaced people who choose to pack up their lives and move far away from the coasts after devastating losses. It's likely that Main Street Capital will have a number of opportunities to put money to work locally when the floods die down, as businesses seek out capital to rebuild after the storm. Of course, we wish the best for Houston and the fine people who call it home. But given Main Street Capital's outsize exposure to the area, investors who rely on its monthly dividends for income should be cognizant of its outsize exposure to investments in and around the Gulf Coast of Texas. 10 stocks we like better than Main Street CapitalWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the 10 best stocks for investors to buy right now... and Main Street Capital wasn't one of them! That's right -- they think these 10 stocks are even better buys. Click here to learn about these picks! *Stock Advisor returns as of August 1, 2017 Jordan Wathen has no position in any of the stocks mentioned. The Motley Fool owns shares of and recommends Facebook. The Motley Fool has a disclosure policy.