|
<br /> Wednesday, May 30, 2007 1:15 PM Nancy Burns (808) 325-1065 O3.
<br /> modificafions to individtuzl properties that are curnntly experiencing tlooding could ;as'. l;r,and
<br /> economically he made I:o solve the problem.
<br /> There are many locations throughout North utd South Kona that experience hca~;, al ; l.ow during
<br /> high intensity tropical storms. Mom alai mitre Irequently folks are building slssh-uri-,ir::~;e ,>tmchzres irn.
<br /> the patlt of this sheet (low with no provisions for diverting the Ilow around the str.us. t r;;:. '1't, restdt. is
<br /> flooding of homes and businesses. This could txw prevented by elevating stntcturce a l d t.r; a ing
<br /> diversion swales around [he buildings. to some instarwes, a simple trench drain ins~:a I'.a: ir, 'rout of a
<br /> building ur garage could. roily and economically rernedy flood issues for homes cu'¢I b,e.i~t:,^ses. The
<br /> proposed atnendtnent requiring all rtntoff {whether gcnv~raled by the development. i~ : t cat; 1 c be cordainx.~l
<br /> vn-site is unrealistic, cost prohibitive, and most importantly it is unnatural.
<br /> Aill 5 t includes amendments to change the "design storm" for alt drainage to the 10~: - yr: u , :4 hoax
<br /> stottn. This does not comport with criteria rued inmost an.as of the Country. For e~ t nz e, acrordirr;
<br /> to'1'able 12-2 Minor Structure DesiXrz Frequencies frnmd on page 582 of Iptxodu~.; a, ii du 'sdrnlc!py,
<br /> Second i3dition by warren vicssman, Jr„ John w. Knapp, Cary L. Lewis, the Iatr,1."c r;a:~ x: h. k:rruauc;ir,
<br /> Harper an<I Row, Publishers, hie. 1977, design sn~ttn liequencies used across the c. fur u•~ in storm
<br /> drainage c:alculaiions very from 2 to 10 years. The Cjvil Lneingering Handlxx>k.,,3~s.c~_r,,c_,dition, t:ditec!
<br /> by W.F. Chen, J.Y. Licw, CRC Press, 2003, slates vn page 32-1 that rainfall witki S to I1: pctr r~occm,nce
<br /> intervals arc. used most often in the sizing and design ol'thc urban stotmwater dnir.;tl aid convr,.rancc:
<br /> systems. The County of Hawaii Storm Drainage Standard specilies the l p-year iI<u~ i,_r r'sorrt. whir:Ja s
<br /> on the high end ofthe scale. `1'he County currently requires higher design slonn Ii+~~q tLn~:ies fir largrr
<br /> watersheds and requires the ] 00-year, 24 hour storm for all FL'MA watercourses. 'I h ~ p;; i' its
<br /> inl'ormalion is helpful in the Counch's evaluation of the adequacy of the C ounty of h: r~r; ri i e Kistir. t;
<br /> storm drainage staruiards.
<br /> i ur~*e the County Council to investigate firrther the causes of specific tlooding iss,t~,,,: unr l ;'e+a: ,m nx,•zrrr
<br /> opinion as to whether the proposed amendments will really cure the problem. There :t v et,r re;a1
<br /> possibilit}~ that the proposed amendrnont will nut selve the problem at all but fined: ,u~i u:~ssi„rrily
<br /> contribute to the already high cast of living here in Hawaii.
<br /> i recommend approval of the amendments proposed by the Department ofYubllc Vhsncs a the caal:ie:,t
<br /> possible date so that the County remains incompliance with FIMA rc-gniremetrts.
<br /> 1 sincerely appreciate the itppinlunily to provide testimony on the subject of Chal:a,:::• ? 7.
<br /> Respectfully Subtrti{t~/te{~d,
<br /> Nancy l;. Burns, Y.L.
<br /> cc 13nzce McClure, .f)irector, Department of public Works
<br /> Galen Kuba, Divisipn Head, Departrnent ol'Puhlie Works, Engineering Divi:~.i~.n
<br />
<br />
|