1998-01-22_AgendaPacket - Laserfiche WebLink

Home

~- - - - -- SECTI®N IV Figure IV-6 F t ~~; .~ .~ ~~' ~' ~. ~ ,. x~ ,f -. ,~ . -;, Recommended Hydroperiod Standards For Wetlands A number of considerations factor into how storm. water should be routed through a natural wetland. The best approach is for local governments to set standards based upon a truly comprehensive watershed management plan that considers local goals for water quality and quantity in conjunction with assessments of wetland functions and values, existing and future land uses, finances available, existing problems, and government structure. Until that has been done, some guidance needs to be followed to limit the negative impacts of storm-water discharges on a community's wetland resources. Based upon the foregoing discussions and in consideration of the chapter on the susceptibility of wetlands to storm-water discharges, the following criteria should be followed when no specific design standards have been established.. Relative Susceptibility Of Wetlands To Storm-Water Impacts ydroperiod ` T-Iighly...; ~ i~To~erafei~ ' Slightly `: ...... feast- s~~anela~rd susceptible ' susceptible susceptible susceptible '' ; 'wetlands ! '' wetlands wetlayicl '' ~vvetlands Storrn,,bounce Existing Existing plus Existing plus No limit :::> :.;;: 0.5 ft 1.0_ft ;:. `a~~scharge rate ;:<: Existing Existing Existing or less Existing or less ':~nu~ndatiflra Existing Existing plus 1 ~., Existing plus 2 Existing plus 7 ::::>: riadfcir I ~z ., day days days .fir. prec~~itatiou ;~nundatiori Existing Existing plus 7 Existing plus 14 Existing plus 21 p'e~rd for 10 ~~r. days days days reap#a:fiota ~'~~Ilt ~ greater Run put°control No change No change 0 to 1.0 feet 0 to 4.0 feet ~l~~tx~n (free above existing above existing ~t~w~n~j run out run out 'It~~-out control Above Above delineated Above Above ~i~:~Fatore delineated wetland delineated delineated {l~~brllocl~ed~ wetland wetland wetland ,~~ ~;~. i Y} 41