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Drainage Infiltration Water~T~J'~T~ . __ T Vancil Road SE @ Birl~land St. SE ~'elrr~, VVA E>;PIRES 4/3/ ~~~ Storm Drainage, Infiltration and Water Quality Report May 14, 2004 Revised December 4, 2004 As-built May 23, 2005 For: Pinedale Construction, Inc. 1151 112`11 Street East Tacoma, WA 98445 By: 2M FiItPY'~Y'lSes, ~ T,~. 15345 Sunwood Blvd. Suite 302 Tukwila, WA 9818 ws, , ~'~. OF AS ~ ~ '®~ ,~ .8148 ~ ~2` ASS/pNAL~N~\ ti~ SITE I,®CATI®1®1 MAP 1 ~~ =1 ~oo~ Reference: The Thomas Guide, King/Pierce/Snohonush Counties, 2000 Edition Autumn Hills 2 - storm I)raina~e, Ynfiltration and Water Quality. Report Project Description The proposed development is a 23-lot residential plat including public streets, storm. drainage conveyance and infiltration, water quality improvement, utilities anal landscaping. The site is located along Vancil Road SE at Birkland Street SE in Ye1m, Washington. Existing; Conditions The total area of the property is 6.0 acres, all of which will be developed as part of this plat. There is currently four stnlctures located on the site including one house anal a few small barns. The house will re~iiain, but all other stnlctures will be removed prior to constriction. The property is bounded by developed residential property to the west and north, Vancil Road SE to the east, and the recently constricted plat of AutLll7ll1 Hills to the south.. Most of the site is very flat. A portion of the southwest corner slopes toward the adjacent residential property to the west. There is a small mound near the the northeast corner of the site, but no other significant topographical features. Tlie site is mainly pasture land, grassy containing small clumps of small to mid-size brush with some scattered trees. There is no evidence of existing storm drainage systems or natural concentrated surface conveyance on the property. There is also no evidence of any upstream storm drainage flowing into the site. Site soils are awell-drained Spanaway series formed in glacial outwash. Based on our field evaluation it appears most if not all storm. drainage inf ltrates into the soils or flows into the wetland/pond area, and there is no nuioff to adjacent properties acid/or public right-of--way. Developed Conditions Development will consist of clearing and grading of the 23-lot residential plat, street paving and associated stone drainage, utility and landscaping improvements. The plat will. be accessed by two new residential streets; an extension of Birkland Street SE on the east side and an extension. of Umptanum Street SE on the south. side. Stone Drainage runoff from the streets and driveways will be collected in a series of catch basins and tightlined to biofiltration swales located adjacent to the proposed low points of Birlcland Street SE and Umtanum Street SE. The bioswales will be designed to provide water quality improvement prior to release into the proposed infiltration pond. The bioswales are designed to treat storm drainage for the 6-montl~/24 hour design event, and. the infiltration pond is designed for the 100-year/24 hour design event. The area draining to the bioswales and i~lfiltration pond is approximately 4.0 acres, of which approximately 2.0 acres is impervious. Roof Drainage will be infiltrated by drywells on individual sites as houses are constructed. The bioswale will need to be lined with an impervious topsoil. layer or geotextile fabric to prevent infiltration into the highly pervious site soils. Sideslopes of the infiltration pond are 3:1 (H:V) and access will be provided to the infiltration pond for maintenance and/or inspection purposes. ST®RM DRAINAGE INIi,ILTRATII~N CALCULATI®NS ~~ I,xr d' 1 L'r`~L~1-'r't u ~o,v' ,rat ` v' ~ z'~ t:Fv 'rG~` ~ c~"." ~,~t-L c, c,~~rr ri ~:..as.S j+,/ ~~`t~.~! 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S"'v 7(>a !~. t~,~ ~~~ rte- ~~- 1,~~~; ~', ~ ~ I '~- ~ ~i ~ ®~~05/22i'2885 21:03 PAGE 81; 84 ~ ~ Ifl 10 ~ ~ ~ ®~ ~ 5/23/05 8:55:16 am ~' age 1 Autumn HiIX 2 Storm Drainage Calculations 2752-00~ BASIN SUMMARY BASIN ID: 6MoDev NAME: 6mo/24hr Developed WQ SBUH METHODOLOGX TOTAL AREA.......: 6.00 Acres ~ASEFLOwS: 0.00 cfs RAINFALL TYPE....: TYPEIA PERV PRECIPITATION....: 1.79 inches AREA..: 3.80 Acres TIME INTERVAL....: 10.00 min CN..._: 77.00 TC._..: 10.00 min ABSTRACTION COEFF: 0.20 PEAK RATE: 0.88 cfs vOL: 0.39 AC-ft TIME: 480 min BASIN ID: Dev-100 NAME: ~.OOy r/24hr Developed SBUH METHODOLOGY TOTAL AREA.......: 6.00 Acres BASEF.LOWS: 0.00 cfs RAINFALL TYPE._..: TYPEIA PERV PRECIPITATION....: 6.15 inches AREA..: 3.80 Acres TIME INTERVAL....: 10.00 min CN....: 77.00 TC....: ].0,00 min ABSTRAC~'ION COEFF : 0 . 2 0 PEAK RATE: 5.76 cfs VOL: 2.23 Ac-ft TIME: 480 min BASIN 2D: SwalEl NAME: 6rno/24hr Developed WQ SHUN METHODOLOGY TOTAL AREA.......: 1.64 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE....: TYPElA PERV PRECIPITATION....: 1.79 inches AREA..: 0.80 Acres TIME INTERVAL..__: 10.00 min CN_...: 77.00 TC._... ].0.00 min ABSTRACTION COEk"F: 0.20 PEAK RATE: 0.32 cfs VOL: 0.13 Ac-ft TIME: 480 min BASIN ID: Swa1e2 NAME: 6mo/24hr Developed WQ SBUH METHODOLOGY TOTAL AREAA.....__.: 1.83 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE._..: TYPEIA PERV PRECIPITATION....: 1.79 inches ARE.A._: 0.93 Acres TIME INTERVAL....: 10.00 rnin CN....: 77.00 TC....: 10.00 mi.n ABSTRACTION COEFF: 0.20 PEAK RATE: 0.34 cfs VOL: 0.14 Ac-ft TIME: 480 min IMP .20 Acres 9T .00 6 . 3 0 min IMP :.20 Acres 91 . 00 6 30 min TMP x.84 Acres 9~ .00 6 3 0 min IMP x.90 Acres 9 .. 00 6 3 0 min 05/22;'2005 21:0 PAGE 02!04 5/23/05 8:55:16 am )age a Autumn Hill 2 Storm Drainage Calculations a~s2-ooi STAGE STORAGE TABLE CUSTOM STORAGE SD No. Trial. Description: Tx~filtration Pond .STAFF <----STOJtS~G,9:----; (f t) ---ef--- -^Ac~Ft- a0.00 0.0000 0,0000 4.8.10 .~, 5'.3.00 0.0039 48.20 507.60 O.D117 48.30 761,40 0,0175 40.40 1015 0,0233 40.50 1269 0.0291 48.60 1323 0.0350 h0.70 1777 0.0408 40.80 2030 0,0466 48.90 2?,04 O.OS2d h9.00 2538 O.O5B3 49.10 2792 0,0641 d9. 20 3046 0.0699 49.30 3?.99 0.0747 49.40 3553 0.0816 49.50 3Pn7 O.o07a 49.60 4061 0.0932 49.70 4315 0.0990 49.60 d560 0.1049 49.90 4822 0.17.07 50.00 5076 0.17,65 50.10 5430 0,1247 X0.20 3704 0.1328 BTAOE <----STORAGE----~ 50.30 6139 0.1409 30.d0 6493 0.1491 50.50 6847 0,1572 50.60 7201 0.1653 50.70 7555 o.173a. 50.80 7910 0.181E 50.90 82 G9 0,1897 3Y.00 0610 0.1970 51.10 9977 o.?o6D 51.20 9326 0,2141 51_]0 9681 0.2222 51,40 10035 0,2304 51.50 10389 0.2395 51.60 10743 0.2466 51.70 11097 0.2548 57..00 11d52 0,2629 51.90 11806 ^.2710 52.00 12160 0.2792 52.10 12561 0.2884 5?..a0 ],2961 0.2975 57.-30 13362 0.3067 52.40 13762 0,3159 52.50 141 G3 0,3281 STAGE <^^--BTORPC-E^---> 52-5D ],4564 0.3343 52,70 14964 0.3435 52.80 15355 0.3527 52,90 15765 0.3619 53.00 16166 0.3711 53.7,0 7,6607 0.3831 53,20 7.7707 0.3950 53.30 17728 0,4070 83.40 18248 0.4183 53.50 19769 0.4309 53.60 19290 0.4428 53.70 19010 0.4540 $3.80 20337, 0,4667 53,90 20857. 0.4.787 54.00 21372 0,490E 54.10 21922 0.5033 54.20 22471 0.8159 54.30 2301.1 0.5209 54.40 23570 0.5411 54.50 24120 0.5537 54.60 24670 0.9663 54,.70 252.19 0.5790 54-e0 25769 0.591fi S'~Ad.F c----3TORAaB----a (fc) ---ef--- --Ac-,Ft- 54.90 26318 0.6042 SS.oO 2606B 0.6168 59.10 J.7424 0.6296 55.20 27987, 0.6?.24 95.30 28537 0.6551 55.40 2909h 0.6679 58.80 29650 0.6807 SS.GO 302.07 0.6935 55.70 30763 0.7062 SS.00 31320 0.7190 55.90 31876 0.7310 56.00 32433 0,7446 56.10 34190 0.7819 56.20 33946 0.8252 SF.30 37703 0.0655 56.40 3946a 0.9059 56,50 41216 0.9462 96.60 d2973 0.9865 56.70 44730 1.0269 SG,80 46487 1.0672 56.30 48243 1.1075 57.00 50000 1,1478 X7.00 50000 1.1470 05i 22%2005 21:03 - PAGE 03!'04 5/23/05 8:55:7 am gage 3 Autumn Hi~.l 2 Storm Drainage Calcuzations 2752-001 STAGE DISCHARGE TABLE DISCHARGE LIST ID No. Tr~.all Description: Znfiltrati.on Discharge STAGS: <--D19CHAAOE---> ,STAGE ~--DIFCHAR6E---a gTACF e--.D7ECP3ARdE---a 3TI~OE ~--DISCHP.RGE---> (ft) ---c,fa-- ------- (f t) -'-cLo-- ------` (ft) ---cfe-- ------- (ft) ---cfa-- ------- 48.00 1.0020 50.30 1.4773 52.60 2.0276 54.90 2.77,44 40.10 1.0223 50.40 1.500,4, 5?..70 2.0537 55.00 2,7500 49,20 7,.0426 50.50 1.5235 52.90 2-0790 53.10 ,2.8000 40.30 1,0629 50.50 l.sg66 52.90 2.1059 55.20 J,.85D0 ae.a0 1.0832 50.70 1.5697 53.00 2.13 J.0 55.30 2.9000 48,50 1,7,035 30,90 1,5928 53.10 Z.7.SBZ 53.d0 2.9500 48-60 1.7,7.3e 50.90 1.6159 53.20 ~.1P4a 55.50 3.0000 49,70 1.,1,447. 31.00 1,6390 53.30 2,2106 35.60 3.0500 48,80 1,1644 .51.10 1.6622 53,40 2,2369 S5.7D 3.1000 48,90 1,1847 57,.70 1.6854 53.50 2,2630 55,80 3,1Sn0 49.00 1.2050 51,30 1.70E76 53.60 2.?.892 55,90 3.2000 49.10 .1-7.253 51.40 1.7318 53.70 2.3154 X6.00 3.2500 49,20 1.2456 31.50 1.7550 53,80 2.341E 56.10 3.3750 49.30 1.2659 51,60 1.779 J. 33.90 2.3678 SG.20 3,4000 x9.40 1.2862 51.70 1.8014 $a-OD 7.3940 56.30 3.4750 49.50 1.3063 51.80 1.8246 54,10 2.4296 Sfi.90 3.5500 49.60 1.3268 57..90 1.8478 54.20 2,4652 56.50 3,6250 43.70 1.3471 S7..D0 7..077,0 34.30 2.5008 56.60 3.7000 49.80 1.3674 52..10 7.-P977, 54.d0 2.3364 56.70 3,7750 49.90 1.3077 52.20 1,9232 54.50 7.5720 56.00 3.0300 50.On 7,. 4,D BO 32.30 1,9633 54.60 2,6076 56,90 3.9250 50.70 1.4311 52.40 1.9754. Sd.70 J.. 643 J. 57.00 6.0000 50.70 L_4542 52.50 2,0015 54.80 2.6799 37.00 4.0000 05;'22;''2005 21:08 PAGE 04; 04 5/23/05 8:55:1.8 am ~ ~ age 4 Autumn. Hill 2 Storm Drainage Calculations 2752-001 LEVEL POOL TABLE SUMMAkZY M71TG13 TNITAVO -£1'0- -DT9- <-PEAFC-> "TORAtlE <--------DE3CRTPTION--^------~ (efo) (cf9) -~id,- --id- !-3T1~GE> 1d VpT,. (cf) 6mo/2hhr rout ................ O.oo 0,80 Tria11 Tr1a7.7, d0.10 1 253.A0 cf. tooyr/2dhr rout .............. 0.00 5.76 Tria11 Triall Sz.So 2 id173.55 cf WATER QUALITY CALCULATION yz~R ,'fit- ~,v"~ c ~°~~ ,'9-~---1 ,~tir~,,~,i,~=/ ,~/~~.t...=~~~..~~ 1~~~,~ ~'J rte. ~ i Y Ii~ .~~~.k' f~ ~`7 ~-~ i r i , /~~, ~~ ;, ` li 7 ~ G'I - D' r /E.1`Z~~~ ~ l N! C~~ .d ~i ~+y~`;~.:)~~~ ~~ ~GJG7l ~' ~~ (//1~tii7 P~~GL~~~,~f `~'C~~`/ ~'L~('~vCrG~' l _~~/'~t~I C~ ~ (c~~/~=' / ` !'s'°T r Y >,~'C,Jt'~Ci2.~77..~ ~j ~?~t...~ ~~a..t.,t`~ y ~~C~"3' lL`s'u _~ . _r- ~ -~- _ _~, C..^'--~.3 ~ l~~j , ~--~`C~-~I,JL~,,~.;-Z,i!'t'`~'J~''T~ ,iC.-~C/'(..!r'M'C'"~ ~- ~~ Get i.,,~.,~,~-~.-t'om' J ~ J%'..~..U ~ ~-~'~ ~-~2s~''!/ ~.,~~ ~~~ ~'~b2v ~ G?~~z~~ t .=~~~t,-;,r1_r.. ~7~_.~:~~ ~ e~~ c;7 i }"~`"~f~ ~" ~,~.-Z~~.;.:il~-e~;:' ~v~..,v~,;~~~.',11~~~,c=,.r V ^"Y ~..~ -~,~ y, ~. ~~~ 1 /`~ C _' Z. i ~ ~ ~~~ Vii: "~ _. ern: _ ~ ~ ~~~ ~I z~~L~ ~ ~ r~~Q~~ ~ u~ Y ~~ II ~~- .3 y~. ~„ ` ~ ~I _..`.Y:,~ ~~z'f,,~,t,-~3'7 !/ ~ G~: Vii:: ~.~ .. 'ii ;: ~! .~ !'i U ~~ '; ~, ,! '~ c~tJ l ~ )~°~ 4? C~ ~~°.. ~c;~ ~ ~ BPS 6~,. ,:~~ ~~~~ _, ~, ~. ~~ 1 .> ~ j /L1 GN~ ~,, Bioswale 1 Worksheet for Rectangular Channel Project Description Project File c:\haestad\fmw\autumnhi.fm2 Worksheet Bioswale 1 Flow Element Rectangular Channel Method Manning's Formula Solve For Channel Depth Input Data Mannings Coefficient 0.300 Channel Slope 0.010000 ft/ft Bottom Width 4.50 ft Discharge 0.32 cfs Results Depth 0.33 ft Flow Area 1.48 ftz Wetted Perimeter 5.16 ft Top Width 4.50 ft Critical Depth 0.05 ft Critical Slope 3.581852 ft/ft Velocity 0.22 ft/s Velocity Head 0.72e-3 ft Specific Energy 0.33 ft Froude Number 0.07 Flow is subcritical. 12/06/04 FlowMaster v5.13 03:47:03 PM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1 Bioswale 2 Worksheet for Rectangular Channel Project Description Project File c:\haestad\fm~n~\autumnhi.fm2 Worksheet Bioswale 2 Flow Element Rectangular Channel Method Manning's Formula Solve For Channel Depth Input Data Mannings Coefficient 0.300 Channel Slope 0.010000 ft/ft Bottom Width 6.00 ft Discharge 0.34 cfs Results Depth 0.28 ft Flow Area 1.69 ftz Wetted Perimeter 6.56 ft Top Width 6.00 ft Critical Depth 0.05 ft Critical Slope 3.725469 ft/ft Velocity 0.20 ft/s Velocity Head 0.63e-3 ft Specific Energy 0.28 ft Froude Number 0.07 Flow is subcritical. 12/06/04 FlowMaster v5.13 03:46:20 PM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of ~ ~~ ~. J_ Z ~ -r __ _... Y J~ -- - _ ~ ~ ~ ~ ~r ~ , ~ J P '` ~ i ~ ~ V ~~ Q e ~~J r <J~` !!! II ~~ 'j ~ \ ~s Qv~o~r 7l~rr~nl - ---~- - _ .~. ~y Y l~'l ~c--~ ~~ ------ --- _~ ~ _ ~~c=~--=-- } -=1-~ ---~-~ I _ m --- ~ '4~ - _. -- _ -~ _ - ~-~_ _ 13.. / _ ~_ o , r x~ ~. ~ \ // ~/ / /~,~- I I ,~ ~/ ~ i ~ ~~ i , ~ i r /, ~ .l l U I ~ ~ ~Q~ ~ ~ ~ l I I I I i \ \ i Q // v v ~ ~ ~ jl ~~ I ~ I Y l ~ ~. ., ~ I ~ 1 ~ y ~, ~ ~ ~ ', 1, - _ ~ ~ ~ ~ - 1 ~ / l ~ i \ ~ I ~ ~ ~' nt ~ ~ i i \ ~ ~' ~~ ~ -~~ -J J I I ~ / - ,- ~~ ~, - ~ ~ ~ , - ~~ - ., . \ ~ ~ ~ _ _ ~ -r- -- - - - -- - / ^+ / i ,/ I ' , , l ~ ~ / I lT _ / -~ - ~ i - ``w I I cn ~ I ~I ,y H I ~ ~ ~- ~ '~ ~ .k i r-appendix A - ®perati~n anal IViaintenance APPENDIX A MAII\TENANCE STANDARDS FOR PRNATELY M AINTAINED DRALNAGE FACILITIES CATCH BASINS Maintenance Defect Component Conditions When Maintenance is Needed Results Expected When Maintenance is performed General Trash & Debris Trash or debris cf mere than 1/2 cubic#oot which is No Trash or debris located (Includes Sediment) located immediately in front of the catch basin immediately in front of catch opening or is blocking capacity of the basin by basin opening. more than 10°/ Trash or debris (in the basin) that exceeds 1/3 the No trash or debris in the catch depth from the bottom of basin to invert the lowest basin. pipe into or out of the basin. Trash or debris in any inlet or outlet pipe blocking more than 1/3 of its height. Dead animals or vegetation that could generate odors that could cause complaints or dangerous gases (e.g., methane). Deposits of garbage exceeding 1 cubic foot in volume Structure Damage to Comer of frame extends more than 3/4 inch past Frame and/or Top 51ab curb face into the street (If applicable). Tap slab has holes larger than 2 square inches or cracks wider than 1/4 inch (intent is to make sure all material is running into basin). Frame not sitting flush on top slab, i.e., separation of more than 3/4 inch of the frame from the top slab. Inlet and outlet pipes free of trash or debris. No dead animals or vegetation present within the catch basin. No condition present which would attract or support the breeding of insects or rodents. Frame is even with curb. Top slab is free of holes and cracks. Frame is sitting flush on top slab. Cracks in Basin Walls/ Cracks wider than 1/2 inch and longer than 3 feet, ,Basin replaced or repaired to Bottom any evidence of soil particles entering catch basin design standards. through cracks, or maintenance person judges that structure is unsound. Cracks wider than 1/2 inch and longer than 1 foot No cracks more than 1/4 inch at the joint of any inlet/ outlet pipe or any evidence wide at the joint of inlet/outlet of soil particles entering catch basin through pipe. cracks. Sediment/ Basin has settled more than 1 inch or has rotated Basin replaced or repaired to Misalignment more than 2 inches out of alignment. design standards. APPENDIX A MAINTENANCE STANDARDS FOR PRN.ATELY MAINTAINED DRAINAGE FACII.ITIES CATCH BASINS (CONTINUED Maintenance Defect Conditions When Maintenance is Needed Results Expected When Component Maintenance is performed Fire Hazard Presence of chemicals such as natural gas, oil and No flammable chemicals gasoline. present. Vegetation Vegetation growing across and blocking more than No vegetation blocking opening 7 0% of the basin opening. to basin. Vegetation growing in inlet/outlet pipe joints that is No vegetation or root growth more than six inches tall and less than six inches present. apart. Pollution Nonflammable chemicals of more than 1/2 cubic foot No pollution present other than per three feet of basin length. surface film. Catch Basin Cover Cover Not in Place Cover is missing or only partially in place. Any open Catch basin cover is closed catch basin requires maintenance. Locking Mechanism Mechanism cannot be opened by on maintenance Mechanism opens with proper Not Working person with proper tools. Bolts into frame have less. tools. than i/2 inch of thread. Cover Difficult to One maintenance person cannot remove lid after Cover can be removed by one Remove applying 80 lbs. of lift; intent is keep cover from maintenance person. sealing off access to maintenance. Ladder Ladder Rungs Ladder is unsafe due to missing rungs, misalignment, Ladder meets design standards Unsafe rust, cracks, or sharp edges. and allows maintenance person safe access. Metal Grates Grate with opening wider than 7/8 inch. Grate opening meets design (If Applicable) standards. Trash and Debris Trash and debris that is blocking more than 20 % of Grate free of trash and debris. grate surface. Damaged or Grate missing or broken member(s) of the grate. Grate is in place and meets Missing. design standards. DEBRIS BARR[ER S (E.G., TRASH RACKS} Maintenance Defect Condition When Maintenance is Needed .Results Expected When Components Maintenance is Performed. General Trash and Debris Trash or debris that is plugging more Than 20% of Barrier clear to receive capacity the openings in the barrier. flow. Metal Damaged/ Missing Bars are bent out of shape more than 3 indhes. Bars in place with no bends more Bars. than 3/4 inch. Bars are missing or entire barrier missing. Bars in place according to design. Bars are loose and rust is causing 50% deterioration Repair or replace barrier to to any part of barrier. design standards. APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAII~ITAINED DRAINAGE FACILITIES ENERGY DISSIPATERS Maintenance Defect Conditions When Maintenance is Needed Results Expected When Components Maintenance is Performed. Extemai: Rock Pad Missing or Moved Only one layer of rock exists above native soil in Replace rocks to design Rock area five square feet or larger, or any exposure of standards. native soil Dispersion Trench Pipe Plugged with Accumulated sediment that exceeds 20 % of the Pipe cleaned/ flushed so that it Sediment design depth. matches design. Not Discharging Visual evidence of water discharging at Trencti must be redesigned or Water Properly concentrated points along trench (normal condition rebuilt to standards. is a "sheet flaw" of water along trench). Intent is to prevent erosion damage. Perforations Over 1/2 of perforations in pipe are plugged with Clean or replace perforated pipe. Plugged. debris and sediment. Water Flows Out Maintenance person observes water flowing out Facility must be rebuilt or =--Top of "Distributor' during any storm less than the design storm or its redesigned to standards. Catch B:..~in. causing or appears likely to cause damage. Receiving Area Water in receiving area is causing or has potential No danger of landslides. Over-Saturated of causing landslide problems. Internal: Manhole/ Chamber Wom or Damaged Structure dissipating flow deteriorates to 1/2 or Replace structure to design Post. Baffles, Side original size or any concentrated worn spot standards. of Chamber exceeding one square foot which would make structure unsound. Other Defects See "Catch Basins" Standard No. 5 See "Catch Basins" Standard No. 5 APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILI'ITES FENCING Maintenance Defect Conditions When Maintenance is Needed Results Expected When Components Maintenance is Performed Genera! Missing er Broker Any defect in the fence that permits easy entry Parts in place ±o provide adequate Parts to a facility. security. Erosion Erosion more than 4 inches high and 12-18 No opening under the fence that inches wide permitting an opening under a exceeds 4 inches in height. fence. Wire Fences Damaged Parts Post out of plumb more than 6 inches. Post plumb to within 1-1/2 inches. Top rails bent more than 6 inches. Top rail free of bends greater than 1 inch. Any part of fence (including post, top rails, and Fence is aligned and meets design fabric) more than 1 foot out of design alignment. standards. Missing or loose tension wire. Tension wire in place and holding fabric. Missing or loose barbed wire that is sagging Barbed wire in place with less than more than 2-1/2 inches between posts. 3/4 inch sag between post. Extension arm missing, broken, or bent out of Extension arm in place with no shape more than 1 1/2 inches. bends larger than 3/4 inch. Deteriorated Paint or Part or parts that have a rusting or scaling Structurally adequate posts or ,Protective Coating condition that has affected structural adequacy. parts with a uniform protective coating. Openings in Fabric Openings in fabric are such that an 8-inch- No openings in fabric. diameter ball could fit through. C.~,ATES Maintenance Defect Conditions When Maintenance is Needed Results Expected When Component Maintenance is Performed General Damaged or Missing Missing gate or locking devices. Gates and Locking devices in Members place. Broken or missing hinges such that gate cannot Hinges intact and tubed. Gate is be easily opened and closed by a maintenance working freely. person. Gate is out of plumb more than 6 inches and Gate is aligned and vertical. more than 1 foot out of design alignment. Missing stretcher bar, stretcher bands, and ties. Stretcher bar, bands and ties in place. Openings in Fabric See "Fencing" Standard No. 8 See "Fencing" Standard No. 8 c APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES CONVEYANC E SYSTEMS (PIPES & DITCHES) Maintenance Defect Conditions When Maintenance is Needed Results Expected When Component Maintenance is Performed Pipes Sediment & Debris Accumulated sediment that exceeds 20% of the Pipe cleaned of all sediment diameter of the pipe. and debris. Vegetation Vegetation that reduces free movement of water All vegetation removed so water through pipes. flows freely through pipes. Damaged Protective coating is damaged; rust is causing Pipe repaired or replaced. more than 50 % deterioration to any part of pipe. Any dent that decreases the cross section area of Pipe repaired or replaced. pipe by more than 20%. Open Ditches Trash & Debris Trash and debris exceeds 1 cubic foot per 1,000 Trash and debris cleared from square feet of ditch and slopes. ditches. Sediment Accumulated sediment that exceeds 20 % of the Ditch cleaned/ flushed of all design depth. sediment and debris so that it Vegetation Vegetation that reduces free mov;-;gent of water matches design. Water flows freely through through ditches. ditches. Erosion Damage to See "Ponds" Standard No. 1 See "Ponds" Standard No. 7 Slopes Rock Lining Out of Maintenance person can see native soil beneath Replace rocks. to design Place or Missing (If the rock lining. standards. Applicable). Catch Basins See `Catch Basins: Standard No. 5 See "Catch Basins" Standard No. 5 Debris Barriers See "Debris Barriers" Standard No.6 See "Debris Barriers" Standard (e.g., Trash Rack) No. 6 GROUNDS (LANDSCAPING) Maintenance Defect Conditions When Maintenance is Needed Results Expected When Component Maintenance is Performed General Weeds Weeds growing in more than 20 % of the landscaped Weeds present in less than 5% (Nonpoisonous) area (trees and shrubs only). of the landscaped area. Safety Hazard Any presence of poison ivy or other poisonous No poisonous vegetation vegetation. present in landscaped area. Trash or Litter Paper, cans, bottles, totaling more than t cubic foot Area clear of litter. within a landscaped area (trees and shrubs only) of 1,000 square feet. Trees and Shrubs Damaged Limbs or parts of trees or shrubs that are split or Trees and shrubs with less than broken which affect more than 25% of the total 5% of total foliage with split or foliage of the tree or shrub. broken limbs. Trees or shrubs thaf have been blown down or Tree or shrub in place free of knocked over. injury. Trees or shrubs which are not adequately supported Tree or shrub in place and or are leaning over, causing exposure of the roots. adequately supported; remove any dead or diseased trees. APPENDIX A MAINTENANCE STANDARDS FOR PRNATELI' MAINTAINED DRAINAGE FACILITIES ACCESS ROADS/ EASEMENTS Maintenance Defect Condhion When Maintenance is Needed Results Expected When Component Maintenance is Performed General Trash and Debris Trash and debris exceeds i cubic foot per 1,000 Roadway free of debris which square feet i.e., trash and debris would fill up could damage tires. one standards size garbage can. Blocked Roadway Debris which could damage vehicle tires (glass Roadway free of debris which or metal). could damage tires. Any obstruction which reduces clearance above Roadway overhead clear to 14 feet road surface to less than 14 feet. high. Any obstruction restricting the access to a 10 to Obstruction removed to allow at 12 foot width for a distance of more than 12 feet least a 12 foot access. or any point restricting access to less than a 10 foot width. Road Surface Settlement, Potholes, When any surface defect exceeds 6 inches in Road surface uniformly smooth Mush Spots, Ruts depth and 6 square feet in area. In general, any with no evidence of settlement, surface defect which hinders or prevents potholes, mush spots, or ruts. maintenance access. Vegetation in Road Weeds growing in the road surface that are Road surface free of weeds taller Surface more than 6 inches tall and less than 6 inches than 2 inches. tall and less than 6 inches apart within a 400- square foot area. Modular Grid Build-up of sediment mildly contaminated with, Removal of sediment and disposal Pavement petroleum hydrocarbons. in keeping with Health Department recommendations for mildly contaminated soils or catch basin - sediments. Shoulders and Erosion Damage Erosion within 1 foot of the roadway more than 8 Shoulder free of erosion and j Ditches inches wide and 6 inches deep. matching the surrounding road. Weeds and Brush Weeds and brush exceed 18 inches in height or Weeds and brush cut to 2 inches hinder maintenance access. in height or cleared in such a way as to allow maintenance access. APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILTITES WATER QUALITY FACILITIES Infiltration Ponds atntenance Defect Component --- Condition When Maintenance is Needed - - Results Expected When Maintenance is Performed Infiltration Pond Vegetation Vegetation such as grass and weeds needs to be Vegetation should be mowed to mowed when it starts to impede infiltration function. 2-inches in height. Trees and Mowing is geherally required when height exceeds bushes should be removed 12 inches. where they impact the infiltrating area of the pond. Sand Filter Layer Sand filter layer has sediment deposits that exceeds Remove sediment and top layer 1/2-inch or the infiltration rate of the sand layer is of sand, and replace in kind per less than 2 in/ hr. specification. Sediment Sediment accumulations in pond bottom that Removal of sediment from pond Accumulation in exceeds 1/2-inch in depth or percolation test of the bottom. Pond Bottom pond indicates facility is only working at 90% of it's design percolation rate. Trash and Debris Accumulation that exceeds 1-CF per 1,000-SF of pond area. Inlet/ Outlet Pipe Inlet/ outlet pipe clogged with sediment and/ or debris material. Erosion Erosion of the pond's side slope and! or scouring of the pond bottom, that exceeds 2-inches, or where potential for continued erosion is prevalent. Sediment of Pond Any part of these components that has settled 4- Dike/Bean inches or lower than the design elevation, or where potential for continued erosion is prevalent. Rock Window Rock window is clogged with sediment. Trash and Debris removed from pond. No clogging or blockage in the inlet and outlet piping. Slopes should be stabilized by using proper erosion control measures and repair methods. Slopes should be stabilized by using proper erosion control measures and repair methods. Window is free of sediment and debris. Overflow Spillway Rock is missing and soil is exposed Replace rocks to specifications APPENDI~i A MAINTENANCE STANDARDS FOR PRNATELY MAINTAII~BD DRAINAGE FACILITIES _ Wetponds Maintenance Defect Condition When Maintenance is Needed Results Expected When Component Maintenance is Performed Wetpond Vegetation Vegetation such as grass and weeds need to be mowed when it starts to impede aesthetics of pond. Mowing is generally required when height exceeds 18-inches. Mowed vegetation should be removed from areas where it could enter the pond, either _ when the pond level rises, or by rainfall runoff. Accumulation that exceeds 1 CF per 1000-SF of pond area. InIeV Outlet pipe clogged with sediment and/ or debris material: Sediment accumulations in pond bottom that exceeds the depth of sediment zone plus 6-inches, usually the first cell. Vegetation should be mowed to ^.-to 5 inches in height. Trees and bushes should be removed where they are interfering with pond maintenance activities. Trash and Debris InIeU Outlet Pipe Sediment Accumulation in Pond Bottom Oil Sheen on Water Erosion Settlement of Pond Dike/-Berm inspector determines dikel berm is unsound Prevalent and visible oil sheen. Erosion of the pond's side slopes and/ or scouring of the pond bottom, that exceeds 6-inches, or where continued erosion is prevalent. Any part of these components that has settled fl- inches- orlower than the design elevation, or Trash and debris removed from pond. No clogging or blockage in the inlet and outlet piping. Removal of sediment from pond bottom. Removal of sediment from pond bottom. Slopes should be stabilized by using proper erosion control measures, and repair methods. Dike/ berm is repaired to specifications. _.... __. Rock Window Rock window is clogged with sediment. Window is free of sediment and debris. Overflow Spillway Rock is missing and soil is exposed at top of Replace rocks to specifications. spillway or outside slope.