On land shaped by wind and water, early settlers came in slow waves to the rolling blackjack and prairie hills that would someday become the city of Tulsa, Oklahoma.
Bottomlands held the lure of easy water, drawing early Caddoan tribes, then the Osage, then the Cherokees. By the late 1700s, Frenchmen were exploring the rivers, giving them names such as Arkansas and Verdigris. By the early 1800s, the Creeks, removed by force to Indian Territory, were torching their council fires on a high bank by the Arkansas River near what would someday be known as Tulsa's Council Oak Tree. Early settlers also were drawn by nearby forts and trading posts, then a post office and a depot ‹ after the railroad came through in 1882, booming the town up to 800 folk. In 1898, Tulsa incorporated. In 1907, Indian Territory became the State of Oklahoma. Growth exploded in the early 1900s with the discovery of oil near Tulsa, continuing strongly during the early decades of this century when Tulsa proclaimed itself to be the oil capital of the world.
Today, Tulsa has about 375,000 citizens, covers about 200 square miles, and is governed by a new mayor-council city government. Its diversified economic base includes oil, aerospace, technical, scientific and communications industries.
Tulsa is located in the middle of "tornado alley," where colliding weather systems make the city vulnerable to violent thunderstorms, particularly in the spring and fall. Normal annual rainfall is about 37 inches, but storms have produced as much as 15 inches of rainfall in a few hours, with little or no warning. Thunderstorms occur principally in the spring and secondarily in the fall; but violent storms know no season and can occur any time of the year.
Its riverfront site also makes Tulsa floodprone; an estimated 10-15 percent of the community is in floodplains. Most of that area is subject to flash floods that strike in minutes during a storm.
A major ridgeline bisects the city, northwest to southeast, so stormwater from a network of smaller basins ultimately drains either to the Arkansas River or the Verdigris River east of Tulsa.
Tulsa's early flood problems generally occurred along the Arkansas River. Disastrous floods occurred in 1908 and again in 1923, when the city's water plant was flooded. (Subsequently, the water plant was moved to higher ground.) Other Arkansas River floods occurred in mid-century years, including the 1940s and 1950s. During World War II, the Corps built Arkansas River levees along portions of Tulsa; in 1964 the Arkansas flood threat was further reduced by an upstream Arkansas River dam, Keystone.
As Tulsa grew, development fanned out across lowlands along the city's network of tributary streams to the Arkansas and Verdigris systems. These smaller, flashy streams became the focus of flooding that generally revisited Tulsa, during the 1960s and 1970s, every two to four years. Several thousand buildings had been built on floodprone lands. Despite piecemeal pipes and paving, damage tolls rose with each flood. The community had few if any regulations over floodplain use, and funds were scarce for structural works.
Notable recent floods occurred in 1970, 1974, 1976, 1984, and 1986. The most damage in those years occurred along Mingo Creek, which drains 61 square miles in east Tulsa. Mingo drains about one-third of the city but has accounted for about two-thirds of the city's flood damages in modern times.
Tulsa's progress in solving its flood problems has come in a series of actions, largely in response to specific floods. After the 1970 Mother's Day flood left $1 million in damages, Tulsa entered the new National Flood Insurance Program and began, slowly, regulating its floodplains.
After the 1974 June 8 flood caused $18 million in damages, Tulsa began a community debate ‹ which was destined to take many years ‹ on the best approaches to flood control.
After the 1976 Memorial Day flood caused $34 million in damages and killed three, Tulsa developed comprehensive drainage regulations and began developing master drainage plans for major creeks. Consensus formed to include channels, stormwater detention, and regulations in the program. The city forged a partnership with the Corps of Engineers, to develop a program for Mingo Creek. A fledgling alert system was developed.
After the 1984 Memorial Day flood killed 14 and left $180 million in damages, Tulsa was shocked into really coming to terms with its flooding problems. A national study showed that Tulsa led the nation in numbers of federally declared flood disasters, with nine flood disasters in 15 years. Leaders recognized that they must install a comprehensive, stable flood-management program with political and fiscal continuity.
After the 1984 flood, the city acquired and cleared about 500 of the most severely damaged houses and mobile homes --- before they were rebuilt --- using combinations of local and federal funds, including flood insurance checks.
In 1986, Tulsa realized the limits of existing Arkansas River flood control levees and dams, when heavy rains forced the Corps of Engineers to release 300,000 cubic feet per second from the upstream Keystone Dam. The high water caused about $3 million in damage at Tulsa, compared to $67 million in the region. This flood focused attention on the need for improved regional planning and coordination. As a result of this flood, Tulsa acquired a swampy pocket of flooded homes along the Arkansas River west bank.
Today, Tulsa's floodplain and stormwater management program includes:
This report focuses on Tulsa's floodplain clearance activities --- one aspect of the city's comprehensive flood-hazard mitigation program --- with emphasis on the 1984 post-flood acquisition.
This report is based on the remarkable work of many people. The list includes Tulsa citizens; many courageous political and civil-servant leaders; a diligent local news media; generous national experts; and our partners in the Federal Emergency Management Agency and the U.S. Army Corps of Engineers. This summary acknowledges their contributions, with gratitude.