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2. Adverse Flood Impacts and Durability The CWCB takes very seriously the flood safety aspects of RICDs, and will carefully consider flood safety in reviewing whether an RICD has been proposed for an appropriate stream reach. The CWCB recommends that an applicant for an RICD demonstrate, through appropriate technical analyses, that the proposed boating course is designed and will be (is) constructed in such a thanner as to: · Adequately pass all flows up to and including the lOO-year (lCYo probablity) flood flow without causing adverse impacts tp upstream, downstream or adjacent property owners. Verification of "no adverse impact" can be demonstrated through the USe of a CWCB approved ste..p p.--bb~ac water hydraulics model such as HEC-RAS. 1,-_ w;~~:f' ~W . Adequately WI and stream forces for e design life of the proposed A ~ recreational facility I flows a~d including the lOO-year flood so that \~'~ damage and failure of the course; is avoided.2 Several people suggested removing this bullet 3. Liability The CWCB assumes no responsibility for use orimisuse of the boating course and is not subject to liability for injuries or damages ca~sed therefrom. CWCB approval of or recommendation to endorse an applicant's proposed RICD water right in no way implies 1 As required by current federal regulations and state 'floodplain management rules (not new guidance developed for the purposes of this document), the applicant is advised that the proposed boating fClcility must be analyzed for flood impacts by modeling the "eXIsting conditions" (pre-facility) scenario and the "proposed conditions" (with-facility) scenario. "The hydrdulic computer modeling must be performed by a registered Professional Engineer (Colorado Registration) having expertise in surface water hydraulic modeling. Impacts that should be analyzed include increqses in water surface elevations for the range of flows experienced at the proposed recreational facility, but especially the lOO-year flood event. According to federal regulations, water surface elevations at the proposed RICD facility may not increase at all (zero rise) in the event that the proposed recreational facility is within a stream reach having a deSignated Floodway (the most hazClrdous portion within the lOO-year floodplain). For reaches thClt are not within a designClted Floodway, any increases in th~ lOO-year flood profile for the proposed RICD facility (up to a maximum of one foot or a lesser amount[specified by local floodplain ordinances or codes, whichever is more restrictive) must be documented. Proper notification of adverse impacts (increased water surface elevCltions) must be provided to affectep property owners and a Letter of Map Revision (LOMR) should be obtained as required by FEMA for National Flood Insurance Program purposes. 2It is recommended tha boating course consist of appropri e materials and installation to endure velocities, shear stresses, othe osive conditions, sedi ation, Clnd debris that would be experienced over its design life. and during high f flood) cond' , ,",s. For example, a boulder drop structure should be constructed with materiClI having suitab such a manner that it is anchored into the st m nk ~nd streambed to survive long-term operation and flood events. Proper durability of the fa ' Ity will aSSI : he applicant in avoiding costly repairs and ; maintenance. and may help to ovoid p ible abandonme~t 0 e RICD water right in the future. e e e 2