Laserfiche WebLink
KING COUNTY, WASHING'CON, SURFACE WATER DESIGN MANUAL <br /> � APPENI)IX A <br /> IVIAINTENANCE STANDARDS FOR <br /> PRIVATELY NIAINTAINED DRAINAGE FACILITIES <br /> NO. 1 -DETENTION PONDS <br /> Maintenance Delect Conditions When Maintenance Resutts ExpeMed WAen <br /> Component Is Needed Malntenance Is Pertormed <br /> General Trazh 8 Debris Any trash:nd debris which exceed 1 cuMe foot TrasA and debris cleared from sAe. <br /> per 1,000 square feet(this is abovl equal to tho <br /> amcunt of t2sh it woutd fake to fill up one <br /> standard size office garbage can). In general, <br /> Ihere sbould oe no visual e�ridence ot dumping. . <br /> Poisonous Vegetation My poisonous or nuisance vegelation whicl� No danger of pofsonous vegetatlon <br /> may constitute a hazartl to Counry personnel a where Counry persormel or tl�e <br /> iha public. public might rrormally be. <br /> (Coordination with Seattle-16ng <br /> Counry Healtli Deparnr�eM) . <br /> PolWtion Oil,gasoiine,or other contaminants of one Mo contartunants present other than <br /> - gallon or more or any amount(ound that could: ` a suAace film. (Coordination with <br /> 1)cause damage to plant,animal,or marine lile; Seattle/fGrg County Health <br /> 2)constitWe a fire hazard;or 3)be Ilushed Department) <br /> downstream during rain slorms. <br /> Unmowed Grass/ If facility is located in private residenGal area, When mowing is needed, <br /> Ground Cover mowing is needed when grass exceeds 78 grass/ground cover should be <br /> inches in hefghL In other areas,the general mowed to 2 inches in height <br /> � ' policy is to make the pond sito match adjacent Mowing ot selected higher use <br /> ground cover ano tertain as long as there is no areaz rallier ihan the entire slope <br /> intederence witb ihe functiou oi the ladlity. may be acceptable for some <br /> � si�ualions. <br /> Hodent Holes My evidence of rodent holes i1 facility is aMing Rodents destroyed and dam or <br /> �s a dam or bertn,or any evidence of water berm repaired. (Caordnation wilh <br /> piping through dam or berm via rodent holes. SeatlleMing Counry Health <br /> Depariment) <br /> Insects When insects such as wasps and homets Insects destroyed or rertwved from <br /> inter�ere with maintenance aclivities. site. <br /> Tree Growth � Tree growth does not ailow maintenance access Trees do rwt hinder maintenance <br /> or interferes wiU�maintenance adivity(i.e.,slope activities. SHectivety cuitivate trees <br /> mowing,silt removal,vactoring,or equ{pment ;uch as alders for firevrood. <br /> movements). It Uees are not intertering with <br /> access,leave Vees alone. <br /> Side Slopes ol Pond Erosion Eroded damage over 2 inches deep where Slopes should be slabilized by <br /> cause of damage is sdll present or where theru usinp appropriate erosion contrd <br /> is polential for continued erosion. measure(s);o.g.,rock <br /> reinforcement,planting ot grass, <br /> compacHon. <br /> Storage Area Sediment Accumulated sediment lha�rzceeds 10°!ot Ihe Sediment cle:uied out to designed <br /> . designed pond depth. pond shape and depth;pond <br /> reseeded if nece:sary to conlyd <br /> erosion. <br /> Pond Dikes Settlements My part oi dike which has settled 4 inches lower Dike should be built back to the <br /> than Ihe desiqn elevatlon. design elevabon. <br /> Emergency Rock Missing Onty one layer of rock ewsts above nativa soil in Repiace rocks to design standarcis. <br /> Overfiow/Spillway area five square feet or larger,or any exposure <br /> oi native soil at fhe top of oul ilow palh ol <br /> spiliway. Rip-rap on inslde slopes need not be <br /> repiaced. <br /> y 1995 Surface Water Design Manual 9!1/98 <br /> A-1 � <br />