7007 SEAWAY BLVD 2018-01-02 MF Import

.._ ,-, . . . . Aveuc woA�rs MEMORANI2UAM TO: Gary Doughry FROM: Jane Zimmerman DATE: February 26. 1996 SUBJE(.'T: Narbeck Swamp Wedand Mitigation Bank �-- 7'hank you fo� �he c�pponunity to commenc on ihe draft Narbeck Swamp Wetland Mitiga[ion Bank prelimirary review daument. My main concern'comment at the moment is the proposal to alter the surface Elow patterns out of Narbeck S��amp {item 4, page 6). Although details of the alteration:ue not given, I am concerned �ha: modifi�:ation would rcduce the ability of the swamp to attenuace storm flows from upstream. The current oudet configuration may not be "natutal", but the restricted oudet is �nhancing the swamp`s stormwater detention capabilities azd hu been doing so long encwgh dia� [ expect :lie swamp's vegetation has adapted co the water level flucr�ations. In my opinion, modifica►ions to �he ou[lec should not be designed to significan[ly affect the flow out of the swamp. However, i[ may be possibiz ro ctansmit the "control pn'snt" downstream to�he nonh propeny line, depending upon the topography of the site and the design of the bank area. A second comment invoives any vehicle parking areas/access roads created fcr the park. Stormwater runoff from chese areas must be treated in aecordance with City standards prior to dischar�e of che stormwater to Nari�eck Swamp. The preliminary review dacument states that Ihis runoff will be treated in a biofiltration swale. It is highly likely that City standards wouid rcquire a wetQond for treatmenc of stormwater nmoff fmm paved aneas. (Infiltration basins are the City's first priority for stottnwatet,treatment; however, given the soils in the area, an infiltration basin would probably not be feasible.) Plea� feel free to contact me with any questions regarding my c:omments. Thr�nk you. ;,��.�„,�