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I L The �e,euned treatment ecll tihall he ncer-e�cacated a mininwnt rf si� inches ;md bruught up Io fin:�l eradc <br /> ��i�h topsuil mccting�it�� specificatinns. <br /> I'_. \'L'eiland �cect;uion shall he planted in accordance ��ith ihc ad��icc of a wetlanJs specialist. Nurscr} sources <br /> for��eiland�epetation an recommended �Shercver possiblc. Small 1=��7 inchl containers are encounged to <br /> �noid transportinc largc amuunts of putting snil to thc pond. <br /> I i. Aceess to the «ctpond. in panicular to the open �cater cell :md am associateJ strucwres, must be procidcd <br /> as rcyuircd in Section �-I.I. <br /> 3.3,_5.? ��iP RD.09 CO:�STRUCTF.D 1VETLAND <br /> General <br /> Constructcd ��ctla:ids are essentialh' larger, mnre"natural" ��:etponds jsec I3�1P iZD.0�1. Thr eoal is tn replicate <br /> natural wctlands as much as possible. "fhcrcforc, constructcd wetlands arc morc eomplc� to build than ordinan <br /> �.et ponc's. Comparecl tu��et prn:ds. =anstructed ��'edands are shallower and Irrve greater sarG�ce area. <br /> Adeyuate hydrefog� an.! appropriate vegetation selection are the t�co mast imponant fac�ors in the succcss uf <br /> construcied wetlands. !n adduion to s�andard hydrologic anahsis.;i ��'ater budcet should be de�eloped tn cnsure <br /> �hat adequatc ��ater ��ill be a�ailable for the constructed wctland to sun�ive and to help determine ,ippropriatc <br /> �vetland plantings. Thc �caicr budect should take imo account emund��ater discharee and recharee, dircct <br /> precipiiation input. e��.iporatiun. and transpiretion from proposecl plantings. <br /> H'possible. stonmvater detention should occur upstrcam of thc constructed ��ctland to avoid water levcl estremcs. <br /> Caretul srlection uf��:uer Iluctuation-tnlernnt penmeter plantin�s «'ill be required if the constnicted wetland �cill <br /> be used tc provide stream bank erosion control,. The DC)E manual c�n be cun,utted ti�r.i mure complete <br /> discussion of thc impacts of fluctuating watcr Icvcls. <br /> Desien Gitcria <br /> I. Constructed we�iands shall have a pertnanent pool volume cyu;il in thr colwne of runof f from thc 6 month. <br /> '_a-hour stonn, usinc dc�cloped sitc conditions. <br /> �. The (ollo�vinE surface arca-pool depth relatiunship, firr thc permancnt poul tihall be meL with a mazimum <br /> a�eraer permanent pool depth of'_A� feec <br /> - iO4o uf the arca at O.i fect (appru�im:ucl}l <br /> - 1 i"o o' thc area Gom 0.� to I �irut <br /> - I�°'o o. thr sirea Gcm '_ �0 3 �ect <br /> - '_0%uf thc arca Gom 3 to b fect <br /> l o maintain n pennancnt pool oP�vnter in a «etland. ioflo�� liom stonm�ater. haseflo��.and cround �cater <br /> must hc grcaler than thc oul�low via intiltration, e�apotranspiration, and discharee. II tha rate of irfiltra[iun <br /> is hi�h and a permanent pnol cannot he maintaincd, a cla� liner ior cc�ui�alcnt)«ill he necessan. <br /> �. ;1 ��et�aulVtank designecl and consiructed in accordance�cith Section i-i.6.I. shoulJ be located at each <br /> inllo�� point to the cons�ructed ��etland. <br /> >, tiidc slupes shall not bc stecper than 3f I:I V. Thcrc should bc an arca of lo�� slope surrounJing thc <br /> pcnnanent puol which is temporarity �luuded during most runotfe�ents but �chich drains �s the runatT <br /> Iea�es the hasin. It i� rccommended that this arca be 10�0 20 fect in �riJth. <br /> n 1 he leneih-to-��idth r�tio ;hall be ;tt Ir;i,t ;:I an� prclerahh �:I. Ilaffles. islands. ur peninsulas ma} bc <br /> uscd Iu incrcasc thc cffecti�c Icneth•to-��idth r.uio. <br /> �-�-3 (rc�� 4'00) <br /> � <br />