History

Policy Framework

Watershed Management

Tulsa's program works because it is based on a unified, logical philosophy.

stormwater as an amenity

The philosophy evolved as Tulsa realized that management systems must take into account two key factors: the timing of flood peaks and the availability of flood storage. This awareness led Tulsa to its watershed-wide management approach to time and space allocation of stormwater.*

It is the foundation on which the program rests. This section highlights excerpts from Tulsa's floodplain and stormwater management philosophy and policy framework.

PRINCIPLES

The urban environment and each watershed within it form a single, interacting system. Actions have consequences.

Floodplain and stormwater management is a matter of time and space allocation. Water requires space and must be stored and conveyed, in either appropriate or inappropriate places.

Floodplains and stormwater are resources. If they can become recreation or beautification assets, so much the better.

Floodplain and stormwater management programs should include multiple purposes and multiple means.

Changes in the natural balance require compensations. Nature bats last.

CORRECTIVE POLICIES

Flood control works include channel modifications and stormwater detention storage. hydrograph

Under certain circumstances, structural projects are necessary to correct past mistakes and provide spot protection. But they must be used with care, because they tend to transfer problems elsewhere, create a false sense of security, and encourage unwise use of the floodplain.

Flood control projects should consider the entire watershed, based on master drainage plans.

Proper, routine maintenance is essential to keep the stormwater systems working.

Acquisition and relocation should be used to reduce, over time, the occupancy and value of exposed property in flood-hazard areas. Any proposal for corrective actions should include a careful analysis of acquisition and relocation alternatives. The value of floodplain lands for urbanization should not be used to justify structural projects. The value of floodplain land for park, recreation and open-space purposes and other natural values should be used to evaluate nonstructural alternatives.

Relocation may be more cost-effective after a flood. Post-flood acquisition should be evaluated and, if possible, pre-planned.

Other essential corrective measures include flood insurance and floodproofing.

PREVENTIVE POLICIES

Public park, recreation, and open space use of the floodplain is the best policy.

mingo lake

Regulatory systems are based on the "100-year flood" under fully urbanized watershed conditions.

Floodplain alterations should be avoided unless they are based on a basin master drainage plan and it can be shown that they will not cause off-site problems.

Regulation of floodplain uses is based on the recognition that: Flooding is a public threat.

Floodplain uses should be compatible with the natural functions of conveyance and storage.

Floodplain uses should not reduce, restrict, or impede channel conveyance capacity, or increase downstream velocities. No changes can take place in the floodplain that decrease or reduce storage. If filling is allowed, compensatory storage must be provided in the floodplain.

stroll

Development should be directed to areas free from flooding. All development within the regulatory floodplain requires a permit.

Stormwater runoff control is necessary because development on higher ground can increase flooding, siltation, and erosion.

Excess stormwater runoff caused by new development should be detained and released at a rate that will not increase peak discharges above that which occurred before development. Generally, regional detention basins are more effective than on-site facilities, unless a specific problem is being addressed.

Public facilities located in the floodplain require special attention.

Other preventive actions include:

Public acquisition of floodplain lands.

Disclosure of flood-hazard information topurchasers and renters.

Flood alert, warning and emergency management systems.

Public information, education and awareness programs.

Development of a post-flood recovery plan, including acquisition of frequently damaged properties; relocation of occupants from floodprone areas; and preservation of floodplain lands for park, recreation and open-space purposes.

From Rooftop to River: Tulsa's Approach to Floodplain and Stormwater Management