(KTXL) — Sacramento’s establishment at the confluence of the Sacramento River and the American River was a strategic one, but it would also be a devastating one for the capital’s early residents, and would shape the future development of the city.

When John Sutter first established Sutter’s Fort, the local Native Americans warned Sutter the Sacramento Valley was prone to flooding and could become a small inland sea, prompting Sutter to build the fort on high ground. (Sutter’s Fort is located 1.5 miles south of the American River and two miles east of the Sacramento River.)

With the influx of people into Sacramento during the start of the Gold Rush, many built their homes and businesses right along the river as open land quickly filled up and the rivers ports offered business opportunities.

According to Sacramento Preservation Historian William Burg, Sutter was absent from the fort during the start of the Gold Rush. Sam Brannan, California’s first millionaire, was also aware of the floods, but took advantage of the fact that 1849 was a drought year to convince people that floods were not a major threat.

In 1850, the first of many floods that would drown Sacramento inspired the city’s first elected mayor, Hardin Bigelow, to build a levee near the confluence of the two rivers. However, this levee would only be a minor barrier to another year of flood waters. In 1851 and 1852, the city was once again submerged.

Following these series of floods the city began its prolonged efforts of raising the city’s streets and buildings higher and higher to try and avoid the flood waters.

Even with these added flood control measures, a perfect storm of weather conditions in 1861 caused a massive flood throughout the state of California that is still considered one of the most expensive natural disasters in state history. The estimated cost of damage was around $100 million in 1862 dollars – the equivalent of $2.89 billion today.

It began with snow coming early than expected in November 1861. Then, a rise in temperature melted the early snowfall into the valley in December.

With saturated soil throughout the state, there were 43 consecutive days of rainfall that brought more than 10 feet of rain along with snow at higher elevations.

What the Native Americans warned Sutter about all those decades ago became true. An inland sea stretched 300 miles north to south and 60 miles east to west in the valley.

This 10- to 20-foot deep mass of water would sit in the valley for six months. The flood killed nearly 4,000 people and 1 million livestock. It also destroyed a quarter of California’s taxable property, nearly forcing the state into bankruptcy.

In Sacramento the levees burst on Jan. 10, 1862, forcing newly elected governor Leland Stanford to take a rowboat to his inauguration.

It also caused the State Capitol to move from Sacramento to San Francisco for six months to allow time for floodwaters to recede and a new Capitol building to be constructed in Sacramento.

“Ironically, one of the major flood control mechanisms, a levee along R Street that supported the Sacramento Valley Railroad’s tracks, made the flood damage worse because the city flooded from the north, and the R Street railroad levee prevented flood waters from draining to the south, until a hole was made in the levee,” Burg said

After the city was underwater for six months, city leaders decided it was time to make a serious effort to reduce flooding – or at the least reduce the damage that flooding caused.

Streets along I, J and K streets were raised an entire story and more substantial levees were built along the Sacramento and American rivers for a start.

“The American River (was moved) farther north and straightened out its route, so the mouth of the river was farther away from downtown; this also included giving the land occupied by the previous river mouth to Central Pacific Railroad whose route out of Sacramento north of downtown served as a far more substantial flood control levee to the north,” Burg said.

Throughout the early and mid-20th century, the creation of more dams and levees helped prevent devastating floods like those in the early 1850s and 1860s from drowning Sacramento again. With the completion of Folsom Dam in 1955, the American River was kept at bay from flooding Sacramento again.

“It clearly worked as Sacramento has not experienced a catastrophic flood of the severity experienced in the 1850, 51, 53 or 61-62 floods,” Burg said.