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<br />t <br />--i <br />_H\ <br />t <br />~ <br />t <br />l <br />l <br />f <br />t <br />, <br />, <br />t <br />t <br />( <br />( <br />[ <br />,. <br />( <br />r <br />, <br />\ <br />" <br />( <br />, <br />,: <br />.. <br /> <br />CHAPTER 1 <br />THE CONCEPT OF NONSTRUCTURAL MEASURES <br /> <br />( <br />i <br />\ <br />( <br />'. <br />r <br />': <br />i <br />i <br />i <br />I <br />i <br />t <br />, <br /> <br />Historical Development <br />The word "nonstructural" has been used for many years as an antonym to the word <br />"structural" to describe alterl;atives to dams, levees, diversions and channel modifications as <br />means to reduce our nation's flood losses. Over the years the concept of nonstructural <br />measures has been expressed by many people in many different ways, In 1945, Gilbert White <br />called for a "geographical approach" to flood control planning and described a variety of <br />adjustments which could be made (1). Some ten years later Hoyt and Langbein articulated the <br />same need and suggested a "unified flood-management" approach be adopted as national <br />policy (2). The concept became national policy in 1966 with the publication of House Document <br />No. 465 and Executive Order 11296 which call for dissemination of information on "alternate <br />methods" and a "broad and unified effort" to lessen the risk of flood losses(3). "Nonstructural" <br />began to be used as the descriptor for these measures in House Document 465 and in an earlier <br />paper by James(4). The concept being expressed by these and other efforts was that there are a <br />variety of ways which can be, and in fact have been, used to reduce flood losses to existing and <br />future development. Traditional "structural" means, which are designed to control flood <br />waters, are one way, however there are a variety of other means and these should be used also. <br />It is not either/or, rather both. <br /> <br />Identification of Nonstructural Measures <br />Measures which have been termed nonstructural include, <br /> <br />. Installation of temporary or permanent closures for openings In structures. <br /> <br />. Raising existing structures in-place, <br /> <br />. Constructing new structures on fill or columns. <br /> <br />. Constructing small walls or levees around structures. <br /> <br />. Relocating or protecting damageable property within an existing structure. <br /> <br />. Relocating existing structures and/or contents out of a flood hazard area. <br /> <br />. Use of water resistant materials in new or existing structures. <br /> <br />. Regulation of development of flood plain land by zoning ordinances, subdivision <br />regulations and building codes. <br /> <br />. Acquisition of title or easement to flood plain land. <br /> <br />. Flood insurance, <br /> <br />. Installation of flood forecast and warning systems with an appropriate evacuation plan. <br /> <br />. Adoption of tax incentives to encourage wise use of flood plain land. <br /> <br />. Placement of warning signs in the flood plain to discourage development. <br /> <br />. Adoption of deve'lopment policies for facilities in or near flood plain land. <br /> <br />While this list may not include all nonstructural measures it includes most of them. All except <br />the last three - tax incentives, warning signs and development policies - are discussed in this <br /> <br />; <br />, <br />, <br />, <br />, <br />( <br />, <br />t' <br />i <br />,. <br />, <br />, <br />,. <br />( <br />i <br />( <br />I <br />I <br />i <br />I <br />( <br />I <br />" <br />" <br />" <br />,. <br />i <br />,. <br />i <br />( <br />, <br />, <br /> <br />1 <br />