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<br />dangerous rainfall combined with snow melt condition. It is <br />bel ieved that precipitation of three to four inches occurring within <br />a one to three day pattern at th€ Spring melt' season wouldpr.oduG:ea <br />crest of water somewhere between eight and twelve feet in height <br />moving through the downtown heart of Boulder. <br /> <br />Our 100 year flood design has recently been updated and currently <br />considered to be a flow of roughly 12,000 to 13,000 cubic feet per <br />second.' It has also been calculated that the major flood of record <br />which occurred in 1894 probably had a discharge in the City of <br />Boulder of approximately 22,000 to 24,000 cubic feet per second. In <br />that particular event, a wall of water was reported at the Sixth <br />Street bridge crossing (prior to the bridge being washed out) <br />approximately 12 feet in height. That was in 1894 when 3,200 <br />individuals lived in Boulder, and tOday, of course, as one might <br />expect, a tremendous commercial and residential development has <br />taken place in the floodway. <br /> <br />However, thereare'c-ertaih very progressiv~ steps that hav€ been <br />taken in recent years in the form of land use policie!; which will <br />undoubtedly mitigate some of the serious flood hazards that are <br />expected in the future. Let me take the liberty oflistihg several <br />of these measures that have been hammered out between local <br />developers, theUrb.an Drainage District; the Planning Commission of <br />the City of Boulder, and eventually the City Council itself. . Much <br />of this activity began back at the turn of the century when Victor , <br />Gruen proposed a flood plain parkway to be s.et aside from the mouth . _\ <br />of Boulder Canyon through the City limits eastward of the cOl11Dunity. <br />The intent of the Gruen plan and consultation by Frederick Law <br />Olmst.ed, Jr., stressed early in the life of the City the need for <br />designation of riparian open space; Today it may sound. surprising <br />that, with the exception of four pri vate structures which sti 11 s.it <br />within the 100 year flood plain, a tremendous swath three to four <br />miles in length has beens.et aside and put into public hands. Some <br />of the land is oWned bytneCity oUtright,some~f thelang>i~9\'1n~d <br />by the University of Colorad6.~and.inadotpartis' olhltha'lelieeri';'se'1/ <br />aside as scenic and natural area, a parking facility, and picnic <br />sites. The four parcels of private in-holdings along the flood <br />plain are earmarked for acquisition at appropriate times when the <br />sellers are ready to vacate thepremi ses. One of those structures <br />has recently been purchased by the City of Boulder and wi 11 be moved <br />out of the flood plain and used for low-cost housing elsewhere in <br />the community. <br /> <br />. <br /> <br />Still another mechanism in addition to land acquisition includes <br />flood plains easements in planned unit development requests. The <br />open space regulations of. the City come into play, and permit the <br />developer to cluster res i dent i a 1 structures at one corner of the <br />parcel in order to qualify forop.en. space and other setback <br />re.gul at ions. It is always mandatory that no residenti al structure <br />be permitted in the 100 year design area. Recent.ordinance activity <br />in 1983 has increased' the flood warning information system and <br />requires all City rental .units to. be identified of flood hazard . <br />conditions, not only on the exterior of their building, but on the <br />