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HomeMy WebLinkAboutMiscellaneous Miscellaneous 12/12/2007 ,. t.. ., Vegetated. Grassy, and Street Swales - - _J Operations & MalnlBnance Plan , Swales are planted or grasSedoPen channels that trap pollutants by fittering and~ng fIow8, allowing particles to settle out. The swale should drain within 48 hours 01 a storm event. A1llacllity components, vegetation, and source controls shall be inspected for proper operations and structural stability, at a minimum, quarterly for the firSt 2 yeal1lfrom the date 01 Installation, 2 times per year thereafter, and within 48 hours after each major storm event. The fadlity owner must keep a log, recording all inspection dates, observations, and maintenance activities. The facility owner must keep a log, recording all inspection dates, observations, and maintenance actlvtties. The lollowlng ~ems shall be Inspected and maintained as staled: Swalelnlet (such as curb cuts or pipes) shall maintain a calm flow of water entering the sware. . Souros 01 erosion shall be Identified and controlled when native soil is exposed or erosion channels are lorming. . Sediment accumulation shall be hand-removed with minimum damage to vegetation using proper eroSion control measures. Sediment shall be removed if ~ Is more than 4" thick or so thick as to damage or kill vegetation. . Inlet shall be cleared when conveyance capacity is plugged. Sources 01 sediment and debris shall be Identified and corrected. "" , '. . . Rock solash pads-shall be reolenished to llrevent erosion. ',1'.-'" ,;~ ,:;::.: .,.,,""'.';'.." Side Slopes shall be maintained to prevent erosion thatlnlroduces s-edlment into the swale. . Slopes shall be stabilized and planted using appropriate erosion control measures when native soli is exposed or erosion channels are forming. ~ SWale Media shall allow stormwater to percolate uniformly through the landscape swate. II the swale does not drain within 4B hours, ~ shall be tilled and replanted according to design specifications. . Annual or s-emi-annualtilling shall be implemented if compaction or clogging continues. I · Debris in quantities that inhiM operation shall be removed routinely (e.g., no Iesa than quarterly), 01' upon discovery . I Swa!e Ou.tlet ~haJI ~I!t~il! she~t filM.'. o! water ex~ing swale unless a collection drain is used. Source 01 erosion damage shall be Identified and cOhtrolled when native soil is exposed or erosion channels are forming. . I . Outiets such as drains and ave~and flow paths shall be cleared when 50% 01 the conveyance capacity Is plugged. i . Sources 01 sediment and debris shall be identified and -" v~;ad. . Vegetation shall be healthy and dense enoug, h to provide fitte~ng while protecting underlying soils from erosion. . Mulch shall be replenished as needed to ensure survival 01 vegetation. . '. . Vegetatlon,large shrubs'or trees.thatlnterfere with landscape swale operation shall be pruned. . Fallen leaves and debris from deciduous plant lollage ehall be removed. . Grassy swales shall be mowed to keep grass 4' to 9' in height. Clippings shall be removed to remove pcillutants absorlled In gras8e8. . . . Nulsanos and' prohibited vegetation from the Eugene Plant Ust (such as b1ackberMs and I:nglish Ivy) shal~be . removed when dlSC9Vered. InvasiVe vegetation cont~buling up to 25% 01 vegetation of allspectes shailbe' . . remoiled and replaced. . . '. .. ~ . Dead veQetatlon and woody material shall be removed to maintain lese than 10% 01 area cOverage~Wh!in SWale ~ -: function' Is Impaired. Vegetation shall be replaced within 3 months, or immediately If required to maimafn 60ver . derni~ and control erosion where soils are exOO8ed. i Spill PreventiOn measures shall be exerd&ed when haildling substances that contaminate stormwater. Releases of i.RD"utants shall be .corrected as soon as identllled; .. . . Tralnlng and/or wrltlBn guidance Information for operating and maintaining swales shall be provided to all properly '; owners and tenants. A cooy of the O&M Plan shall be provided to all 'Jrooerty owners and tenants. -:11 Access to the swele shall be sale and efficient. Egress and Ingress routes shall be maintained to design standards. j RoadWays shall be maintained to accommodate size and weight 01 vehides, if applicable. I . Obstacles preventing maintenance personnel and/or equipment access to the swale snail be removed. I . Gravei or around cover shall be added il erosion occurs, e.l1.. due to vehicular or oedeslrian traffic. , 5 Ie; (IdlY I~CU~, k ?-.. ') 7-- <), i1 J.. JA.-1 D 0 IY II- LU,-e H ?i{-;L , ;(-6 Stormwater Management Manual Eugene July 2006 Page 3-20 Date Fl.eceived:~/}dP7 Planner: AL -.- .- .. Vegetated, Grassy, and Street Swales Operations & Malnlllnance Plan Insects & ROdents shall not be harbol~~'in the swale. Pest control measures shall be .~~en when insects/rodents are found to be present. . If a complaint is received or an inspection reveals that a stormwater facility is significantly infested with mosquitoes or other vectors, the property owner/owners or their designee may be required to eliminate the inlestation at the City Inspector's discretion. Control of the inlestatlon shall be attempted by using first non' chemical methods and secondly, only those chemical methods specifically approved by the City's inspector. Acceptable methods include but are not lim~ed to the following: i) Installation 01 predacious bird or bat nesting boxes. ii) A~erations 01 pond water levels approximately every lour days in order to disrupt mosqu~o larval development cycles. iii) Stocking ponds and other permanent water facil~les with fish or other predatory species. iv) If non-chemical methods have proved unsuccessful, contact the City inspector prior to use 01 chemical methods such as the mosqu~o larvicides Bacillus thurengensis var. israeliensis or other approved . I larvacides. These materials may only be used with City inspector. approval if evidence can be provided ~ that these materials will not migrate off-s~e or enter the public stormwater system. Chemical larvicides shall be applied by a licensed individual or contractor. . Holes in the Qround located in and around the swale shall be filled. ; If used at this site. the followlf!g will be applicable: : Check Dams shall control and distribute flow. U .. Causes lor a~ered water flow shall be identified, and obstructions cleared upon discovery. p Causes lor channelization shall be identified and repaired. Stormwater Management Manual Eugenejuly 2006 Page 3-21 ~;, .~ -' ".',{" :;}:.!\' Date Received:~Jib~ Planner: At: 7