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81-08 - Ord. Amending Ord. 114-06 County Code Chapter 14.48 Stormwater Management
Ordinance N o . -08 MASON COUNTY S'L'ORMWA'I'KR MAN Gil-I:V EY l' ORDINANCE Amending Mason County Stormwater Management Ordinance No. 114-06 and Mason County Code Chapter 14.48 WH NREAS, the1994 Puget Sound Water Quality Management Plan (as amended) requires all counties and cities within the Puget Sound drainage basin to adopt ordinances to control runoff from new development and redevelopment by January 1,1995; and WHEREAS, the plan directs local governments to adopt the stormwater programs which include minimum requirements for new development and redevelopment set by the Plan and in guidance developed by lHcology. WHERES, the implementation of the Storm Water and Surface Water Utility, Chapter 14.46 of the Lason County Code, created and adopted on :une 17, 2008; and W1'r',RES, the minimum requirements of the 2005 ll�;dition of the Department of Ecology's Stormwater Manual are adopted by reference for the Allyn and Belfair Urban Growth Areas (UGA's) and other areas as defined or added pursuant to Chapter 14.46 of the Mason County Code; and T WJ. �! the. HR1KAS, areas outside of the Storm and Surface Water Utility are governed by provisions of 992 Department of Ecology Stormwater Manual WH IHREAS, a public hearing was held on June 17, 2008 in the Commission Chambers to take public comment and consider proposed revisions. NOW ITE Eh-�ORE, J-3E ORDAINED by the Mason County Board of County Commissioners does hereby amend the Mason County Stormwater Management Ordinance. ADOPTED this ATT lip; S' II Zcartei REBIECCA S. ROG E PROVED AS day of i (me , 2008 17tv ta.e.) S, Clerkof the Board 0 FORM: J secutor BOARD OF COUNTRY COMM:SSIONERS MASON COUNTY, WAS - INGT OI\ ( „st, Ls47k.e, TIM SHELDON, Chair ,YND RING FRIFICSON, Commissioner RTII C AR'II'ICI ,E SON C O U mending Mason Co and H INDIN GS OF. FACT, Findings of. fact Nee Y S'l'ORMWA'I'E i M NAG l►E V_;- NT ORDINANCE Ordinance No. e / -08 unty Stormwater Management Ordinance No. 114=06 Mason County Code Chapter 14.48 _ \ EED 1 CON S `__ ] �111 S 1 0 o u u o 0 0 0➢ 0 0 0 o e o 0 o 0 0 0 0 0 0 0 o c o 0 0 0 0 0 0 0 o e e o o c o 0 0 0 o C 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0➢ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0➢ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 o 0 0 0 0 0 0 0 c o 0 0 0 0 0 0 0 0 0 0 0 0 d0 0 0 0 0 0 0 0 0 0➢ 0 0 0 0➢ 0 O➢ 0 0 0 0 0➢ 0 0 0 0 0 0 0 0 0➢➢ 0➢ 0 0 O➢ 0 0 0➢ 0 0 0 0 O O 0 O 0 O O O 0➢ e v O O O o 0 0 0 0 0 0➢ 0 0 0 o O 0 0 O O 0 0 O 0 O O e o u o o u e v o 0 o u v n O o➢ o O o 0 0 0 o O O➢➢ O O e O O Purpose... 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GENERA P O Y is anua 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0➢ 0 000 00 000 ONJ 0 0 0 O 0 0 0 0 0 0 0 0 0 0 0 O O 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 C 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 C 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Abrogation and greater restrictions nterpretation CILE V; APPL _CA-11!Lll'i'Y.0. 0 0 0 c 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 v o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00 0 0 0 o e 0➢➢ 0➢ 0 0 o u 0 0 0➢ o e 0 0 0 0 n 0 n 0 0➢ 0 0 0 0 0 o e 0 0 0 0 0 0➢ e e e u o 0 0 0 o n 0➢ 0 0 0 0➢ e 0 n 0 0 0 0 0 0 0 0 0 0 u e 0 0 0 0 0➢ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0➢ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0➢➢ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0➢. 0 0➢ c 0 0 IC It ,E VI: RED T I ,A' : l ACTIVEIES ND 6.1 1e2111 ate lA L a et1V 1t1a S.000000000000000000000000000000000000000000000000000000000000000000000000000000000e 0000000000000o 0 ,OWED CTIV-T • . • 3 3=4 4 4 Hl 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0. 5 6.2 EIemptio n s000 0 0000000000000000000Co000000oon0uoovnoanonn00n0o0➢0oe000000➢0oeo➢oon0oocoe000n0o0oco00o00Ooo0000co0eCovc0o 5 _C ,` I ' \JII• GENE R ME1 VSo00oeo000000000oOCOo00ouo0➢e 7.1 1992 Stormwater Management Manual or the Puget Sound Basin Adopted ..o on no0e00➢neon ne➢ 0 0 0 C 0 0 0 0 0 0 0 0 OW n 0 0 0 0 0 0 0 000 0 0 0 0 0 0 0 0 0 c 000 0 0 0 00 0 o n 0 v ono ➢ L. 0 0 0 0 0 0➢ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 6 6 7.2 Stormwater Best Management Practices(BMPs)...o➢.➢e0ee➢0000oD0000en➢On0.000000000.0➢➢➢00➢➢0.... 00 6 7.3 Illicit Discharges..... 0 0 0 c 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 n o 0 0 n e o 0 0 0 o e 0 o 0 o n 0 0 0 0 0 0 0 ono ocean 0 0 c op o c o 0 0 o u o 0 0 0 0 0 0 0 0 0 0 0 o n e o 000 0 0 0 0 0 0 0 n n 0 6 ARTICLE APPROVAL STANDARD S➢➢......00➢.......0000.......➢➢.➢00900000➢➢➢➢000000➢0000➢0000➢000o000n000000➢300➢n000 6 8.1 Small Parcel Minimum Requirements 0➢ O 0 0 0 n 0 0 0 e 0 c O o c n c n c n n➢ n n➢ e 0 0➢ 0➢ 0 0 0 0 0 0 0 0➢ 0➢➢ 0➢ 0 0 0 0➢ O 0 0 0 CO CO % 0 C➢ 0➢ G o a 0 n 0 V 8.1.1 Small Parcel Requirement #1 Construction AccessRoute ........➢ 0 0➢➢ 0 0 0 n➢ e 0➢ 0 0 0 0➢ 0 0 000 n n n o o 00 n o e 0 0 0 0➢ 0➢ 0 n e➢ 0 e 0 e 0➢➢ on 8.1.2 Small Parcel Requirement #2 Stabilization of Potentially Erodible Denuded Areas0➢00000000➢0ooee.ee➢o0➢000000➢0tcoma 00➢00➢➢ 0 0 0 7 8.1.3 Small Parcel Requirement #3 Protection of Adjacent Properties ➢➢ n 0 0➢ 0➢ e➢ e➢ 0 0 0 O➢ 0 0 0 0➢ O n 0 COC➢ 0 0 0 0 0 0 0 0 0 0 n 0 0 0 0 0 o n n u o n n 0 n n n 0 n➢ 0 0 n➢ 0➢ 0➢ 0➢ 0➢ 0 e 0 0 0 8.1.4 Small Parcel Requirement #4 Maintenance0 0➢ 0 0 0 0 0 o e o 0 0 0 0 0 0. o o 0 0 0 0 0 o 000 0 0 0 0 0 0 0 0 0 0 0 0 0 COMOOOU 0 0 0 0 0 0 o n n o 0 0 0 0 o r. ono 0 0 0 0 o u o➢ o c c 0 0 o u. 0 0 0 0 0 0 0 0 0 0 o O 00 0 0 0 0 0 0 0 0 n 7 8.1 e 5 Small: Parce _ Requirement 115 Other_ I.1 VIP s 0 0 0 0 0 0 0 0 0 0 e 0 0 0 0 0 0 0 0 0➢ 0 0 Coat 0 0 0 c 0 0 0 0 0 0 0 0➢ 0 0 0 0 e 0 0 0 0➢ o 0 0 0 0 0 0 0➢ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 e r. 0 0 C 0 0 0 ! 8.2 8 o 2 0 1 8.2.2 802.3 New )cvelopment and ''` edeve;o iment Minimum{equirements....0➢e➢..n➢➢..➢➢0..➢ New V e w Development 0 0 0 0 0 0 0 0 0 0 0 0 0 0➢ e 0 0 0 0 0➢ 0 0 0 0 0 0 Oa 0 0 0 0 0. 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 c 0 0 0 0 0 o 0 0 0 Redevelopment 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 000 0 0 0 0 0 0 0➢ 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 e 0 0 0 0 0 0 0 0 0 0 0 0 n 0 0 0 0 0 0 0 0. 0 0 0 0 0 0 ,}/'� s `1_1' 0 0 0 0 O O n o 0 0 0 0 0 0 0 0 0 o O O 0 0 0 o 0 0 0 0 0 0 0 0 0 0 c 0 0 `U' 0 0.➢ 0 0 o u u o 0 u o u o c 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 o e o 0 0 o n o e o 0 0 0 0 0 0 0 0 0 0 0 0➢ 0 0 0 0 0. 0 0 0 0 0 o e 0 0 o 0 0 0 0 o 0 o 0 0 0 0 0 0 'l.Y -9 Minimum Requirement # Erosion and Sediment Contro 00000000000 0 0 0 0 0 0 0 0 0 0 0 0 0 0➢ 0➢ 0 0 0 0➢ 0 e 0 0 0 0 03300 0➢ 0 0 0 0 O C 0 o 0 O 0 0 0 0 0 0 0 0 0 0 o e 2 M A SON COJ TY S 8.2.4 Minimum Requirement #2 Preservation of 1\ 8 2.5 Minimum Requirement #3 Source Control of Poi ution 'ocarina o a o o a o a no o o a o a o op o a o 0 o 0 o a a o o a o 0 0 0 o v a o 0 0 o a o 0 0 o a a 0 0 0 o a 0 0 0 v o 0 0 o a 8.2.6 Minimum Requirement #4 Runoff A,at1 n e nt IIIVIP s 000000000000000000 00 0000000000000000 0000000 00 00000000000000000000000000000 8.2.7 Minimum Requirement #5 Streambank Erosion Control o0v00o0 000000000000000000000000000000000000000000000 00000000 000000 8.2.8 inimum Requirement #6 Wetlandsa a o 0 o a a o 0 0 0 0 0 0 0 0 0 0 0 0 o a a o on o coo o 0 0 o a a o o c o a o v on c o co n o 0 0 0 0 0 o a e e pea ea co a a s o a e e e o o 0 0 0 o c o a o 0 o v o v a o o a a o o o a 8.2.9 Minimum Requirement #7 Water Quality Sensitive Areas 000000000000000000000000000000000000000000000000000000000vWOO Ono 8.2.10 Minimum Requirement #8 Offsite Analysis & Vitigation 00000000000000000000000v 00000e 00 DO 00 o e 000 000 8.2.11 VVinimum iequirernent #9 BasinPlanning 0000000000 0000000000 as oaa 000000013e000000000000000000000 as 00000000000000000000000000000a00 8.2.12 Vinimurn Requirement 410 Operation and Vainter] once 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 a o o v 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 n v 0 0 o a e 0 0 0 0 o 0 0 o o a a o 0 o a o e a o o e n o 0 8.2.13 Minirnum1Requirerent # 11 Financial Liability u 0 0 0 v 0 0 0 0 0 0 0 0 c 0 a 0. 0 DOCc 0. 0. 0 0 0 0 0.. 0 0. 0 0 0 0 0 a 0 0 0 0 0 0 0 0 0 Oa e 0 0 0 0 0 a 0 0 c 0 0 v 0 0 0 0 0 0 0 0 n o c o o e 0 0 0 0 0 e. 0 0 0 0 0 0 0 0 0 0 0 o a a 0 0 n o o. 8.2.14 Variances From These Standards. 8.2.15 Experimental BMPs 0 o n n o n e o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 c 0 0 a o 0 0 0 0 0 0 0 0 0 0 0 0 0 0: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 o 0 0 0 0 0 0 0 0 0 a 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 e 0 0 0 0 0 0 0 0 0 0 0 0 0 a 0 0 0 0 0 0 000 0 0 0 0 0 0 0 0 c a 0 0 0 o a o o a e 0 0 0 0 00 0 0 0 0 0 0 0 0 0 0 0 0 0 u 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 8.2.15.1 Approval of 1Kxperirnen to AR' I'ICU, IX: ADMIX S'_'RATION ARTIC 9.1 9.2 9.3 9.4 Director oa000aco.00. 000eoo0000 Review and Approval H;nforcement Authori Inspection o.o. 0aa.e.. 00. a .aa 3MPs 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 n 0 e 0 0 a 0 0 0 0 0 0 0 0 0 0 0 0 0 a 0 0 0 0 n 0 0 0 0 e 0 0 0 a a 0 0 0 0 0 0 0 a a 0 0 0 0 0 0 a 0 0 c ORMW ER M ANAG Ordinance No. CO S (co ORDI\T NCE -©8 to) a iara.l Drainage Systems LLs 0 0 0 0 0 0 0 0 0 0 0 0 0 0 a v o 0 0 0 0 0 e 000 0 0 0 0 0 0 0 0 0 0 00 0 0 0 0 0 v 0 0 0 0 12 3 13 13- 14 14 4 14-15 15 16 16 16 17 17 000 o c o v 0 a c 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 a o o 0 a o a n o n 0 o a 0 o a 0 o e mown 0 0 n a o a o e 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 u. 1 7 a o o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 o 0 0 0 0 0 0 0 0 000 0 0 0 0 0 0 o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 a a a 0 a o n a o a 0 e 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 17 0 a on a o e e o.. o a 11 a a 0 0 0 0 0 n 0 0 a a a DOCIDOCIO 00 0 0 0 o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 a 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 c o o 0 0 0 0 0 0 0 0 0 0 0 0 17 00ee00000000000000aaaaa0a00oen0cow 0aav00v0aaneoono 000coaaGeoauoono aneaea00000000000ea0000 18 a. c o 0 a 0 0 0 c o a c 0 0 c 0 c 0 0 0 0 0 v e c 0 a 0 v 0 0 0 0 0 0 v v 0 a a e e. a a a v 0 0 0 0 c 0 a 0 0 a 0 a 00 0 a n a a c 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 a c 0 0 0 0 ell. 1 8 H; X : ENF O RCEl EN"tvaeaDeeaeacaaoaavo0voavan0eaeaaav0aaaaa0oeaoovaaavaaaaaaaoaavavaavvov00aeaaoeeocoaae0a.oaaaaaaDooen.aaa1 S 10.1 General ...o........voaaaaa000aaaooco0 0eo000e00v00000V0aa0en0c00000000000va0aceaeae00aa0a00a000000000e000veeea000000000accc 18 10.2 Stop Work Order 0000000 00000000 600000000000000 000000000000000000000000000a00000000000e0000000..evavvvvvacon eca00ea 18 10.3 Civil Penalty..avv0v0aoe0ooacooevevaecao0oo00vauvaomoe0e0000000aaao0c0acavavaa.a0Co0Uo000000000000000000eaac00a00a0vvaao 19 1 0.3.1 Penalties Due OD OOOOOOOOO 0000000 00000G000000000000000000001300000000000000000000000000e000000000000000000.0000000 1 9 1 0.3.2 Penalty Recovered vanaaanaaaaoo00e0vaaanvaeeeeeaavacaacoauaavvceacaceaaaaaavvveaavoaaaa0e0a0aa0aveveeavaco 20 AR7y C li1E XI: EXCEPTIONS .000.0000000000000000000300000000000000000e0000000000C00000100000000000000000000000ae0000000000000000t000 1 1 e1 Right of Appeal 00000000000000000000000000 00000000000000000000000000 a 00000000000 a a a. 000v 0 v 000 as 000*000e 0000000 00000 1 1.2 Findings of Fact 000000000000000000000000000000000000000000000o0000 0000000000000000000000000 aaaceaanvvo00v0c0oaavc0ca I1 e3 Prior Approval 0000000000C 0ee0011u0au0000000000000.00000000001100000000000000000i. a 000000000 00000004000000100000e0000000000 1 1 a 4 Duration and Exception o000000000neaa0a0000000o0000000Jaa00000000000000 eac00ueoa0naocaaca0oeeeoen0eoacoacoaeaaeou 1 1. 5 3 o ar d of L 1L p p.l a v o 0 o e o 0 o o e o e e c o o e o o e e o a o 0 0 o c o v o v c v v o a e o o a o 0 o a a o 0 0 o a o v o o u u o c o u o 0 0 v o a c o o o a v a o o a o 0 o a a o (' o c a 2 ,0 ART C II , )C1.I o S K V Il JR 1 20 20 20 20 20 .11 o v o o v o 0 0 0 0 0 o v v 0 0 v 0 0 0 0 0 0 0 u 0 c 0 0 0 0 0 0 0 0 0 0 0 0 0 0 u 0 0 0 OW 0 0 0 0 0 0 0 0 0 0 0 0 0 v v o 0 0 0 o v e o o a 0 o a c e o a o a o o a o 0 0 a a a v o v o v a o v o 0 0 APPEND— L ]1 A. v 00 v 0 GLICIDOCID 0 0 0 0 0 0 0 0 0 0 0 o 000 000 00 0 0 0 o a a o p v 0 000 0 0 c v u u a u v u u 0 0 0 u on u 0000 v C. 0000 0 CO v 000 a v 0000 0 0 0 0 0 pa 000 v 0000 2,1 MASON COUN Y STO A. 1 2005 Departmen of lEco _ V L V V A I II JR M Ordinance Noe -08 G 0 ( D CON T HN 'I (cont.) ogy Stormwater Management Vanua - For Western Wasiington. 992'Depart en t of For JA CF 0 0 0 0 0 0 eta no noontime on e e o o e 0 e o 0 0 0 o o 0 o 0 woo o 0 o 0 o 0 0 0 0 0 0 Fie° ogy Storcmwatcrr 1 t nua Puget Sound 3asin 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 o 2 ._ '22 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 2 -2 3 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE ARTICLE I: FINDINGS OF FACT, NEED AND PURPOSE 1.1 Findings of Fact The Board of Mason County Commissioners of Mason County hereby finds that: 1. This ordinance is divided into two parts The first part defines requirements within the area covered by the Storm and Surface Water Utility. Development actions in these areas will be governed by the 2005 Edition of the Department of Ecology's Stormwater Manual. The Belfair and Allyn UGA's are included in the Storm and Surface Water Utility, which was created on June 17, 2008. Other areas of the county may be added as described in Chapter 14.46, to the Storm and Surface Water Utility. The second part of the ordinance will regulate development in areas outside the Storm and Surface Water Utility including any areas added in the future Areas outside of the Storm and Surface Water Utility are governed by provisions of the 1992 Department of Ecology Stormwater Manual. 2. The 1994 Puget Sound Water Quality Management Plan (as amended) requires all counties and cities within the Puget Sound drainage basin to adopt ordinances to control runoff from new development and redevelopment by January 1, 1995 The Plan also directs local governments to adopt stormwater programs, which include minimum requirements for new development and re- development set by the Plan and in guidance developed by Ecology. 3. Stormwater is a problem associated with land utilization and development and common occurrence of potential pollutants such as pesticides, fertilizers, petroleum products, animal wastes and numerous others. Land utilization and development is also known to increase both the volume and duration of peak flows. The resulting erosion, scouring, and deposition of sediment affect the ecological balance in the stream. Sedimentation and stormwater pollution cause diversity of species to decrease and allows more tolerant (and usually less desirable) species to remain. Stormwater pollution can cause or contribute to closures of shellfish beds and swimming beaches and other restrictions on public use of the waters within Mason County. 4. An expanding population and increased development of land have led to: Water quality degradation through discharge of nutrients, metals, oil and grease, toxic materials, and other detrimental substances including, without limitation, insect and weed control compounds; Drainage and storm and surface water runoff problems within Mason County; and Safety hazards to both lives and property posed by uncontrolled water runoff on streets and highways. 1 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE 5. Continuation of present stormwater practices, to the extent that they exist, will lead to water quality degradation, erosion, property damage, and endanger the health and safety of the inhabitants of the County. 6. In the future such problems and dangers will be reduced or avoided if existing properties and future developers, both private and public, provide for stormwater quality and quantity controls. 7. Stormwater quality and quantity controls can be achieved when land is developed or redeveloped by implementing appropriate best management practices (BMPs). 8. Best management practices can be expected to perform as intended only when properly designed, constructed and maintained. 1.2 NEED The County finds that this Ordinance is necessary in order to: 1. Satisfy the mandate of Ecology as identified in Section 1 2 2. Minimize or eliminate water quality degradation. 3. Prevent erosion and sedimentation in creeks, streams, ponds, lakes and other water bodies. 4. Protect property owners adjacent to existing and developing lands from the undesirable impacts of increased runoff rates. 5. Preserve and enhance the suitability of waters for contact recreation, fishing, and other beneficial uses. 6. Preserve and enhance the aesthetic quality of the water. Promote sound development policies, which respect and preserve County surface water and sediment. 8. Ensure the safety of County roads and rights -of -way. 9. Decrease stormwater-related damage to public and private property from existing and future runoff. 10. To protect the health, safety and welfare of the inhabitants of the County. 1.3 PURPOSE The provisions of this ordinance are intended to guide and advise all who conduct new development or redevelopment within Mason County The provisions of this ordinance establish the minimum level of 2 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE compliance, which must be met to permit a property to be developed or redeveloped within Mason County. It is the purpose of this Ordinance to: 1. Minimize water quality degradation and sedimentation in streams, ponds, lakes, wetlands and other water bodies; 2. Minimize the impact of increased runoff, erosion and sedimentation caused by land development and maintenance practices; 3. Maintain and protect groundwater resources; 4. Minimize adverse impacts of alterations on ground and surface water quantities, locations and flow patterns; 5. Decrease potential landslide, flood and erosion damage to public and private property; 6. Promote site planning and construction practices that are consistent with natural topographical, vegetational and hydrological conditions; 7. Maintain and protect the County stormwater infrastructure and those downstream; 8. Provide a means of regulating clearing and grading of private and public land while minimizing water quality impacts; and 9. Provide guidance on development and construction procedures, which will encourage the preservation of existing natural vegetation to the maximum extent practicable. ARTICLE II: DEFINITIONS For Definitions, see Appendix "A". ARTICLE III: STORMWATER UTILITY 3.1 2005 Stormwater Management Manual for Western Washington Adopted The minimum requirements of the 2005 edition of Ecology's Stormwater Management Manual for Western Washington are adopted by reference for the Allyn and Belfair Urban Growth Areas (UGA' s)and other areas as defined or added pursuant to Chapter 14.46.As the boundaries of the Mason County Stormwater Utility are amended to include additional area, the minimum requirements of the 2005 Manual shall apply to those additional areas. For infoiuiation about the utility boundaries, responsibilities, and financial management see Chapter 14.46 In addition to the minimum requirements of the 2005 manual, for new development and redevelopment, 3 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE no additional stormwater runoff shall be allowed from the property due to added impervious surfaces or disturbed land. The stormwater runoff from new impervious surfaces or disturbed land shall be treated and prevented from flowing off the property being developed. ARTICLE IV: GENERAL PROVISIONS 4.1 Abrogation and greater restrictions It is not intended that this Ordinance repeal, abrogate, or impair any existing regulations, easements, covenants, or deed restrictions However, where this Ordinance imposes greater restrictions, the provisions of this Ordinance shall prevail. 4.2 Interpretation The provisions of this Ordinance shall be held to be minimum requirements in their interpretation and apphcation and shall be liberally construed to serve the purposes of this Ordinance. ARTICLE V: APPLICABILITY Regulated activities shall be conducted only after Mason County Public Works approves a Stormwater Site Plan, which includes one or more of the following as required by this Ordinance: 1. Small Parcel Erosion and Sediment Control (ESC) Plan 2. Residential Site Improvement Plan accompanied by a written description of the proposed work and improvements. 3. Large Parcel Erosion and Sediment Control (ESC) Plan 4. Permanent Stormwater Quality Control (PSQC) Plan accompanied by a written description of the proposed work and improvements. Note: Small activities creating less than 2000 square feet of new imperviousness will be required to submit item "1". Residential site development creating more than 2000 square feet of new impervious surfaces will be required to submit items ` l & 2". Non-residential activities creating more than 5000 square feet of new imperviousness will be required to submit items "3 &4", prepared by a licensed civil engineer. Residential or non residential site development that disturbs an acre or more of land will be required to submit items 3&4 prepared by a licensed civil engineer. 4 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE ARTICLE VI: REGULATED ACTIVITIES AND ALLOWED ACTIVITIES 6.1 Regulated activities Consistent with the minimum requirements contained in this Ordinance, the Director or their designee shall approve, conditionally approve, or disapprove the following activities, unless exempted in Section 6.2 below: 1. New Development A. land disturbing activities; B. structural development, including construction; installation or expansion of a building or other structure; C. creation of impervious surfaces; D. class IV general forest practices that are conversions from timberland to other uses; E subdivision, short subdivision and binding site plans, as defined in CH.58.17.020 RCW. 2. Redevelopment A. on an already developed site, the creation or addition of impervious surfaces, structural development including construction, installation or expansion of a building or other structure, land disturbing activity, and/or replacement of impervious surface that is not part of a routine maintenance activity, and land disturbing activities associated with structural or impervious redevelopment. 6.2 Exemptions Commercial agriculture, and forest practices regulated under Title 222 WAC, except for Class IV General forest practices that are conversions from timberland to other uses, are exempt from the provisions of this Ordinance. Development undertaken by the Washington State Department of Transportation in state highway right- of-way is regulated by Chapter 173-270 WAC, the Puget Sound Highway Runoff Program. All other new development and redevelopment is subj ect to the minimum requirements of this Ordinance. 5 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE ARTICLE VII: GENERAL REQUIREMENTS 7.1 1992 Stormwater Management Manual for the Puget Sound Basin adopted The 1992 edition of Ecology's Stormwater Management Manual for the Puget Sound Basin with the exception of the Minimum Requirements Chapter, Volume I, Chapter 2, is hereby adopted by reference to all areas of the County except those noted in Article III The use of other manuals or methods shall be pre -approved by the Director or their designee 7.2 Stormwater Best Management Practices (BMPs) General: BMPs shall be used to control pollution from stormwater. BMPs shall be used to comply with the standards in this Ordinance BMPs are in the 1992 Manual. Farm Plan BMPs: For new development that will include "hobby farm" elements such as pastures, corrals, etc, farm plan BMPs are recommended (not required) for incorporation into the site design. Contact Mason County's Public Works Department or the Mason Conservation District for further farm plan guidance. Experimental BMPs• In those instances where appropriate BMPs are not in the 1992 Manual, experimental BMPs should be considered. Experimental BMPs are encouraged as a means of solving problems in a manner not addressed by the 1992 Manual in an effort to improve stormwater quality technology. Experimental BMPs must be approved in accordance with the approval process outline in the 1992 Manual. 7.3 Illicit discharges Illicit discharges to stormwater drainage systems are prohibited. ARTICLEVIII: APPROVAL STANDARDS 8.1 Small parcel minimum requirements 1. The following new development shall be required to control erosion and sediment during construction, to permanently stabilize soil exposed during construction, to comply with Small Parcel Requirements 1 through 4, to prepare a Small Parcel Erosion and Sediment Control Plan, and may need to prepare a Small Parcel Drainage Plan/Sketch (Mason County's Pubhc Works Department can provide additional instructions, guidance, and examples if a Small Parcel Drainage Plan is deemed necessary): A. Creation or addition of less than 2,000 square feet of impervious surface area. B. Land disturbing activities of less than one acre. 6 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE 8.1.1 SMALL PARCEL REQUIREMENT #1 Construction Access Route Construction vehicle access shall be, whenever possible, limited to one route. Access points shall be stabilized to minimize the tracking of sediment onto public roads. Wherever construction vehicle access routes intersect paved roads, provisions must be made to minimize the transport of sediment (mud) onto the paved road. If sediment is transported onto a road surface creating a hazard, the roads shall be cleaned immediately, and thoroughly cleaned at the end of each day. Sediment shall be removed from roads by shoveling or sweeping and be transported to a controlled sediment disposal area. Street washing shall be allowed only after sediment is removed in this manner 8.1.2 SMALL PARCEL REQUIREMENT #2 Stabilization of Potentially Erodible Denuded Areas Soil stabilization All exposed and unworked soils with erosion potential shall be stabilized by suitable application of BMPs, including but not limited to sod or other vegetation, plastic covering, mulching, or application of ground base on areas to be paved All BMPs shall be selected, designed and maintained in accordance with an approved manual. From October 1 through April 30, no soils shall remain exposed for more than 2 days. From May 1 through September 30, no soils shall remain exposed for more than 7 days. 8.1.3 SMALL PARCEL REQUIREMENT #3 Protection of Adjacent Properties Adjacent properties shall be protected from sediment deposition by appropriate use of vegetative buffer strips, sediment barriers or filters, dikes or mulching, or by a combination of these measures and other appropriate BMPs. 8.1.4 SMALL PARCEL REQUIREMENT #4 Maintenance All erosion and sediment control BMPs shall be regularly inspected and maintained by the owner or authorized agent to ensure continued performance of their intended function 8.1.5 SMALL PARCEL REQUIREMENT #5 Other BMPs As required by the Director, other appropriate BMPs to mitigate the effects of increased runoff shall be applied. 8.2 NEW DEVELOPMENT AND REDEVELOPMENT - MINIMUM REQUIREMENTS Development of individual, detached, single-family residences and duplexes exceeding 2,000 square feet of impermeable surfacing must have a Small Parcel Erosion and Sediment Control Plan, and a Residential Site Improvement Plan (which includes a written description of the proposed work and development) prepared and submitted for County review and approval. Non-residential development .exceeding 5,000 square feet of impermeable surfacing and/or land disturbing activities of one acre or more must have the Large Parcel ESC Plan (if required) and the 7 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE Permanent Stormwater Quality Control (PSQC) Plan (if required) prepared and stamped by a licensed civil engineer, 8.2.1 New Development All new non-residential development that includes the creation or addition of 5,000 square feet, or greater, of new impervious surface area, and/or land disturbing activity of one acre or greater, shall comply with Minimum Requirements #1 through #11 in Sections 8.2.3 through 8.2.13. Compliance shall be demonstrated through the implementation of an approved Stoiiiiwater Site Plan consisting of a Large Parcel ESC Plan and a PSQC Plan, as appropriate. 2. All new non-residential development that includes the creation or addition of 5,000 square feet, or greater, of new impervious surface area, and land disturbing .activity of less than one acre, shall comply with Minimum Requirements #2 through #11 in Sections 8 2 4 through 8.2.13 and the Small Parcel Minimum Requirements found in section 8.1 above This category of development shall also prepare a Stormwater Site Plan that includes a Small Parcel Erosion and Sediment Control Plan. Compliance shall be demonstrated through the implementation of an approved Stormwater Site Plan that includes a Small Parcel Erosion and Sediment Control Plan and a PSQC Plan. 3. All new residential development and redevelopment (individual, detached, single family residences and duplexes) that includes the creation or addition of 2,000 square feet, or greater of new impervious surface area, shall prepare a Small Parcel Erosion and Sediment Control Plan which complies with Minimum Requirements #1 through #5 in Sections 8.1.1 through 8.1.5, and shall prepare a Residential Site Improvement Plan which includes a written description of the proposed work and development, The Small Parcel Erosion and Sediment Control Plan along with the Residential Site Improvement Plan should show and describe how development impacts are proposed to be mitigated. Compliance shall be demonstrated through the implementation of approved Erosion and Sediment Control Plan, and a Residential Site Improvement Plan 8.2.2 Redevelopment 1. Where non- residential redevelopment of >_ 5,000 square feet occurs: The new development Minimum Requirements #1 through #11, Sections 8.2.3 through 8.2.13, shall apply to that portion of the site that is being redeveloped, and source control BMPs shall be applied to the entire site, including adjoining parcels if they are part of the project. A Stounwater Site Plan shall be prepared. 2. In addition to the above requirements, where one or more of the following conditions apply, a Stormwater Site Plan shall also be prepared that includes a schedule for implementing the Minimum Requirements to the maximum extent practicable, for the entire site, including 8 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE adjoining parcels if they are part of the project. An adopted and implemented basin plan (Minimum Requirement #9) may be used to develop redevelopment requirements that are tailored to a specific basin. A. Existing sites greater than 1 acre in size with 50% or more impervious surface. B. Sites that discharge to a receiving water that has a documented water quality problem. Subject to local priorities, a documented water quality problem includes, but is not limited to water bodies: (i) Listed in reports required under section 305(b) of the Clean Water Act, and designated as not supporting beneficial uses; (ii) Listed under section 303(d) of the Clean Water Act as not expected to meet water quality standards or water quality goals; (iii) Listed in Washington State's Non -point Source Assessment required under section 319(a) of the Clean Water Act that, without additional action to control non -point sources of pollution cannot reasonably be expected to attain or maintain water quality standards. C. Sites where the need for additional stormwater control measures has been identified through a basin plan, the watershed ranking process under Ch. 400-12 WAC, or through Growth Management Act planning. 8.2.3 MINIMUM REQUIREMENT #1: Erosion and Sediment Control All new development and redevelopment that includes land disturbing activities of one acre or greater shall comply with Erosion and Sediment Control Requirements 1 through 14, below. Compliance with the Erosion and Sediment Control Requirements shall be demonstrated through implementation of a Large Parcel Erosion and Sediment Control Plan. All new development and redevelopment that includes land disturbing activities of less than 1 acre shall comply with the Small Parcel Minimum requirements found in section 8 1, above. Compliance with the Small Parcel Requirements shall be demonstrated through implementation of a Small Parcel Erosion and Sediment Control Plan. The following erosion and sediment control requirements shall be met: A. EROSION AND SEDIMENT CONTROL REQUIREMENT #1: Stabilization and Sediment Trapping All exposed and unworked soils shall be stabilized by suitable application of BMPs. From October 1 to April 30, no exposed and unworked soils shall remain unstabilized for more than 2 days. From May 1 to September 30 , no exposed and unworked soils shall remain unstabilized for 9 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE more than 7 days. Prior to leaving the site, stormwater runoff shall pass through a sediment pond or sediment trap, or other appropriate BMPs. B. EROSION AND SEDIMENT CONTROL REQUIREMENT #2: Delineate Clearing and Easement Limits In the field, mark clearing limits and/or any easements, setbacks, sensitive/critical areas and their buffers, trees, and drainage courses. C. EROSION AND SEDIMENT CONTROL REQUIREMENT #3: Protection of Adjacent Properties Properties adjacent to the project site shall be protected from damage by sediment deposition. D. EROSION AND SEDIMENT CONTROL REQUIREMENT #4: Timing and Stabilization of Sediment Trapping Measures Sediment ponds and traps, perimeter dikes, sediment barriers, and other BMPs intended to trap sediment on -site shall be constructed as a first step in grading. These BMPs shall be functional before land disturbing activities take place. Earthen structures such as dams, dikes, and diversions shall be seeded and mulched according to the timing indicated in Erosion and Sediment Control Requirement # 1. E. EROSION AND SEDIMENT CONTROL REQUIREMENT #5: Cut and Fill Slopes Cut and fill slopes shall be designed and constructed in a manner that will minimize erosion In addition, slopes shall be stabilized in accordance with Erosion and Sediment Control Requirement #1. Supplemental Guidelines: Consideration should be given to the length and steepness of the slope, the soil type, upslope drainage area, ground water conditions, and other applicable factors. Slopes which are found to be eroding excessively within two years of construction must be provided with additional slope stabilizing measures until the problem is corrected. (i). Roughened soil surfaces are preferred to smooth surfaces on slopes (see BMP E2.35 in Chapter II-5). (ii) Interceptors (see BMP E2.55 in Chapter II-5) should be constructed at the top of long steep slopes, which have significant drainage areas above the slope. Diversions or terraces may also be used to reduce slope length. (iii) Concentrated stormwater should not be allowed to flow down cut or fill slopes unless contained within an adequate temporary or permanent channel, or pipe slope drain (see BMP E2.25 in Chapter II-5). 10 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE (iv). Wherever a slope face crosses a water seepage plane which endangers the stability of the slope, adequate drainage or other protection should be provided (BMPs E2.30 and E2.75 in Chapter II-5). F EROSION AND SEDIMENT CONTROL REQUIREMENT #6: Controlling Off -site Erosion Properties and waterways downstream from development sites shall be protected from damage by erosion due to increases in the volume, velocity, or peak flow rate of stormwater runoff from the project site. G. EROSION AND SEDIMENT CONTROL REQUIREMENT #7: Stabilization of Temporary Conveyance Channels and Outlets All temporary on -site conveyance channels shall be designed, constructed and stabilized to prevent erosion from the expected velocity of the peak flow from a 2-year, 24-hour frequency storm for the developed condition. Stabilization adequate to prevent erosion of outlets, adjacent stream banks, slopes and downstream reaches shall be provided at the outlets of all conveyance systems. H. EROSION AND SEDIMENT CONTROL REQUIREMENT #8: Storm Drain Inlet Protection All storm drain inlets made operable during construction shall be protected so that stormwater runoff shall not be discharged offsite or be introduced into any fill area without first being filtered or otherwise treated to remove sediment I. EROSION AND SEDIMENT CONTROL REQUIREMENT #9: Underground Utility Construction The construction of underground utility lines shall be subject to the following criteria: (i) No more than 500 feet of trench shall be opened at one time, unless provisions are made to protect against adverse stormwater impacts. (ii) Where consistent with safety and space considerations, excavated material shall be placed on the uphill side of trenches (iii) Trench dewatering devices shall discharge into a sediment trap or sediment pond. J. EROSION AND SEDIMENT CONTROL REQUIREMENT #10: Construction Access Routes Construction vehicle access shall be, whenever possible, limited to one route. Access points shall be stabilized to minimize the tracking of sediment onto public roads. 11 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE Wherever construction vehicle access routes intersect paved roads, provisions must be made to minimize the transport of sediment (mud) onto the paved road. If sediment is transported onto a road surface creating a hazard, the roads shall be cleaned immediately, and thoroughly cleaned at the end of each day. Sediment shall be removed from roads by shoveling or sweeping and be transported to a controlled sediment disposal area. Street washing shall be allowed only after sediment is removed in this manner. K. EROSION AND SEDIMENT CONTROL REQUIREMENT #11: Removal of Temporary BMPs All temporary erosion and sediment control BMPs shall be removed within 30 days after final site stabilization is achieved or after the temporary BMPs are no longer needed. Trapped sediment shall be removed or stabilized on site. Disturbed soil areas resulting from removal shall be permanently stabilized. L EROSION AND SEDIMENT CONTROL REQUIREMENT #12: Dewatering Construction Sites Trench dewatering devices shall be discharged in a manner that will not adversely affect flowing streams, drainage systems, or offsite property. Water discharged from dewatering pumps shall be routed through a sediment pond or trap unless it is clear M. EROSION AND SEDIMENT CONTROL REQUIREMENT #13: Control of Pollutants Other Than Sediment on Construction Sites All pollutants other than sediment that occur on -site during construction shall be handled and disposed of in a manner that does not cause contamination of stormwater. N. EROSION AND SEDIMENT CONTROL REQUIREMENT #14: Maintenance All temporary and permanent erosion and sediment control BMPs shall be maintained and repaired as needed and in a timely manner to assure continued performance of there intended function All maintenance and repair shall be conducted in accordance with an approved manual. O. EROSION AND SEDIMENT CONTROL REQUIREMENT #15: Financial Liability Performance bonding, or other appropriate instruments, may be required to ensure compliance with the approved erosion and sediment control plan. 8.2.4 MINIMUM REQUIREMENT #2: Preservation of Natural Drainage Systems Natural drainage patterns shall be maintained, and discharges from the site shall occur at the natural location to the maximum extent practicable. 12 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE 8.2.5 MINIMUM REQUIREMENT #3: Source Control of Pollution Source control BMPs shall be applied to all projects to the maximum extent practicable. Source control BMPs shall be selected, designed, and maintained according to an approved manual. An adopted and implemented basin plan (Minimum Requirement #9) may be used to develop source control requirements that are tailored to a specific basin, however, in all circumstances, source control BMPs shall be required for all sites 8.2.6 MINIMUM REQUIREMENT #4: Runoff Treatment BMPS All projects shall provide treatment of stormwater. Treatment BMPs shall be sized to capture and treat the water quality storm, defined as the 6 month, 24 hour storm The first priority for treatment of stormwater shall be to infiltrate as much as possible of the water quality design storm into the ground (Infiltration BMP's practices shall be in accordance with Chapter III-3 of the PSWQA Manual) Pretreatment of stormwater prior to infiltration into the ground may be required in cases where: 1. The stormwater contains high concentrations of undesirable dissolved chemicals that can move through soil. 2. The stormwater contains large amounts of sediment that might clog the infiltrative surfaces in the basin. 3. The soils are extremely pervious and will not properly filter the stormwater as in the case for some gravelly (Type One) soils. Stoiiuwater treatment BMPs shall not be built within a natural vegetated buffer, except for necessary conveyance systems as approved by the Director. An adopted and implemented basin plan (Minimum Requirement #9) may be used to develop runoff treatment requirements that are tailored to a specific basin. The objectives of providing stormwater treatment BMPs are, for both surface and ground waters, to protect the quality and quantity, to allow attainment of the designated uses, and to meet state standards promulgated under Chapter 173 of the Washington Administrative Code. 8.2.7 MINIMUM REQUIREMENT #5: Streambank Erosion Control The requirement below applies only to situations where stormwater runoff is discharged directly or indirectly to a stream, and must be met in addition to meeting the requirements in Minimum Requirement #4, Runoff Treatment BMPs• Stormwater discharges to streams shall control streambank erosion by limiting the peak rate of runoff from individual development sites to 50 percent of the existing condition 2-year, 24-hour design storm while maintaining the existing condition peak runoff rate for the 10-year, 24-hour and 100- year, 24-hour design stoiius. As the first priority, streambank erosion control BMPs shall utilize 13 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE infiltration to the fullest extent practicable, only if site conditions are appropriate and ground water quality is protected. Streambank erosion control BMPs shall be selected designed, and maintained according to an approved manual. Stormwater treatment BMPs shall not be built within a natural vegetated buffer, except for necessary conveyance systems as approved by the Director, and maintained according to the 1992 Manual. An adopted and implemented basin plan (Minimum Requirement #9) may be used to develop streambank erosion control requirements that are tailored to a specific basin. 8.2.8 MINIMUM REQUIREMENT #6: Wetlands Stormwater discharges to wetlands shall maintain the wetland's natural hydroperiod and flows to the extent needed to preserve or enhance its existing functions and values. Prior to proposing discharge of higher volumes of stormwater to a wetland, alternative discharge, detention, and infiltration practices located in areas outside the wetland shall be evaluated and employed by the Project Engineer where feasible and practicable. These requirements apply to existing natural wetlands and wetlands created as mitigation for loss of wetland acreage. Wetlands constructed and operated solely for use as stotniwater treatment / storage areas are exempt from these and most other restrictions that apply to natural wetlands. Constructed wetlands may lose this exemption if not operated and maintained as stormwater areas for three or more years. Other local, state, or federal wetland protection requirements may also apply. 8.2.9 MINIMUM REQUIREMENT #7: Water Quality Sensitive Areas Where the Mason County Commissioners or their designee determine that the Minimum Requirements do not provide adequate protection of water quality sensitive areas, either on -site or within the basin, more stringent controls shall be required to protect water quality. An adopted and implemented basin plan (Minimum Requirement #9) may be used to develop requirements for water quality sensitive areas that are tailored to a specific basin. 8.2.10 MINIMUM REQUIREMENT #8: Off -Site Analysis and Mitigation DOWNSTREAM ANALYSIS MAY TRIGGER ADDITIONAL REQUIREMENTS The Project Engineer shall provide a detailed qualitative analysis of the flow path of the discharge from the project site to the receiving water. This requirement shall apply to all projects where a Drainage and Erosion Control Plan is prepared, including those proposing retention facilities. This analysis shall include flow routing, and provide existing pipe and channel sizes and estimated capacities. In addition, the Project Engineer shall discuss any known or expected downstream erosion, flooding, or water quality problems, including those that may be caused by interflow from the proposed retention facility The Director or designee shall have the discretion to specify the distance and level of detail to be provided by the Project Engineer In making this determination, the Director or designee shall consider such factors as the relative size of the new development, 14 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE availability of other hydrologic work for the drainage area, and the extent to which stormwater generated on the project site is to be infiltrated. Based upon this analysis, the Project Engineer may determine or the Director or designee may require that a quantitative analysis of the conveyance system be performed both upstream and downstream of the project site. A quantitative analysis will not be required for most projects that propose to infiltrate most or all stormwater. This analysis shall determine conveyance system performance for the appropriate design event(s) both with and without the proposed development The Director or designee shall have the discretion to specify the distance and level of detail to be provided by the Project Engineer The Director or designee shall consider factors such as the relative size of the new development, availability of other hydrologic work for the drainage area, and the results of the qualitative analysis, in making this determination The quantitative downstream analysis will include modeling the hydraulics of the proposed project and all other sources of runoff tributary to the receiving water body for the appropriate Design Event The Project Engineer shall include an analysis of the impact of the 24-hour, 100-year event (in addition to "Design Event' analysis) for each component of the system including pond spillway. The Director or designee may impose stricter discharge and/or detention standards if the discharge from the project, evaluated in the context of other existing conditions in the drainage area, is reasonably expected to result in any of the following: A. Flooding B. Loss of aquatic habitat due either to high or low flows C. Property Damage D. Water quality problems E Erosion F. Or an unacceptable interruption of vital services. If the Project Engineer (or Director or designee) determines that greater treatment, infiltration and/or storage volumes, lower release rates, or downstream improvements are needed, he/she shall specify project design criteria or other means to relieve the downstream problems (providing that such solution will not violate minimum standards established in the 1992 Manual). Other means might include increases in downstream flow capacity and/or offsite detention and infiltration facilities, plans and financing for which will be subject to the approval of the Director or designee. 8.2.11 MINIMUM REQUIREMENT #9: Basin Planning Basin Plan Supersedes 1992 Manual. If a proposed Project is located in a basin or sub basin for which the County has an adopted basin plan, stonnwater requirements specifically identified in the basin plan shall take precedence over those provided in this Ordinance. However, all other elements detailed in this Ordinance shall continue to apply to such projects. Basin Plans are required to be developed according to an approved manual. 15 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE 8.2.12 MINIMUM REQUIREMENT #10: Operation and Maintenance An operation and maintenance schedule shall be provided for all proposed stormwater facilities and BMPs, and the party (or parties) responsible for maintenance and operation shall be identified. An Operation and Maintenance (O&M) Covenant will be required to cover all privately owned and maintained stormwater facilities approved by the Director. O&M Covenant forms are available at the Mason County Public Works office. A copy of the completed instrument, shall be recorded with the County Auditors' Office by the proponent and a copy of the recorded instrument is required to be submitted to the Public Works Department prior to final approval of the completed permanent stoiiuwater facilities. 8.2.13 MINIMUM REQUIREMENT #11: Financial Liability Performance bonding, or other appropriate instruments shall be required for all projects to ensure compliance with these standards 8.2.14 VARIANCES FROM THESE STANDARDS Variances from these standards may be allowed at the discretion of the Director or designee provided that the Proponent will substantially meet flow control and water quality goals established by or implicit in these standards. Compliance with Ordinance requirements shall normally occur within the project area, but may be performed as offsite mitigation in certain situations Examples of cases when variances may be approved includes, but are not limited to, the following: A. That the special conditions and circumstances exist which are peculiar to the land, such as size, shape, topography, or location, and that literal interpretation of these standards would deprive the property owner of rights commonly enjoyed by other properties similarly situated; OR B That the site is being remodeled and certain site investigations would be destructive to existing structures OR C. That remodels of existing projects which are either too small or so configured that in the Director's or designee's opinion some requirements of the manual cannot practically be met; OR D. That public works or private sector projects are in an existing road right-of-way which is not of adequate size to install preferred BMPs and for which right-of-way cannot be expanded because of encroaching structures or setbacks for existing structures. All requests for variances must be submitted in writing to the Director or designee, and must clearly state the specific Section(s) of the Ordinance from which a variance is requested and why 16 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE 8.2.15 EXPERIMENTAL BMPs Experimental best management practices are defined as BMPs, which have not been tested and evaluated by the Department of Ecology in collaboration with local governments and technical experts. Some so-called Experimental BMPs will likely be minor variations on an existing theme. In that case, Ecology would review and approve or disapprove the BMP in as timely a manner as possible Where new designs are developed (examples of experimental BMPs may be found in Section I-2.17.2 of the PSWQA Manual), the review will be extended through the use of a standing committee of technical experts. These persons will review and comment on the practice, and Ecology will then determine whether or not these BMPs should be approved and/or added to the manual. 8.2.15.1 APPROVAL OF EXPERIMENTAL BMPs Approval to use an Experimental BMP may be granted subject to initial approval by the Department of Ecology and the local government. If such Experimental BMPs prove useful they may be incorporated into later editions of the Manual following appraisal of the results and appropriate technical review conducted by Ecology in collaboration with local governments and other interested parties. Approval to use an Experimental BMP will only be granted when a suitable contingency plan using approved BMPs has been provided by the applicant to be used in the event that the Experimental BMP does not perform adequately. In addition, several Experimental BMPs have been included in the 1992 Manual. People may wish to use these BMPs on a trial basis, subject to approval by the local government and provision of a contingency plan. In any event, use of Experimental BMPs is encouraged whenever applied research is being undertaken so that more information is made available to facilitate judgement on their applicability and possible adoption as an approved BMP. ARTICLE IX: ADMINISTRATION 9.1 Director The Mason County Public Works Director or a designee shall administer the technical requirements of this Ordinance and shall be referred to as the Director The Director shall have the authority to develop and implement administrative procedures to administer and enforce this Ordinance. Responsibilities for the stormwater utility are defined in Chapter 14.46 of the Mason County Code. 9.2 Review and approval The Director may approve, conditionally approve or deny an application for activities regulated by this Ordinance Copies of Sections 9, 10, 11, & 12 shall be given to all applicants. 17 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE 9.3 Enforcement authority The Director shall enforce this Ordinance. 9.4 Inspection All activities regulated by this Ordinance, except those exempt in Section 6.2, are subject to inspection by the Director The Director may inspect projects at various stages of the work requiring approval to determine that adequate control is being exercised. Stages of work subject to inspection include, but are not limited to, pre -construction; installation of BMPs; land disturbing activities; installation of utilities, landscaping, retaining walls and completion of project. As required by the Director, inspections and/or testing shall be perfoimed by the owner or authorized agent. ARTICLE X: ENFORCEMENT 10.1 General Enforcement action shall be in accordance with this Ordinance whenever a person has violated any provision of this Ordinance The choice of enforcement action and the severity of any penalty shall be based on the nature of the violation, the damage or risk to the public or to public resources, and/or the degree of bad faith of the person subject to the enforcement action. 10.2 Stop work order The Director shall have the authority to serve a person a stop work order if an action is being undertaken in violation of this Ordinance. 1. Content of Order. The order shall contain: A. A description of the specific nature, extent, and time of violation and the damage or potential damage; and B. A notice that the violation or the potential violation cease and desist, and, in appropriate cases, the specific corrective action to be taken within a given time. A civil penalty under Section 9 3 below may be issued with the order. 2. Notice. A stop work order shall be imposed by a notice in writing, either by certified mail with return receipt requested, or by personal service, to the person incurring the same. 3. Effective Date The stop work order issued under this Section shall become effective immediately upon receipt by the person to whom the order is directed. 4. Compliance. Failure to comply with the teinis of a stop work order shall result in enforcement actions including, but not limited to, the issuance of a civil penalty. 18 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE 10.3 Civil Penalty A person who fails to comply with the requirements of this Ordinance, who fails to conform to the terms of an approval order issued, who undertakes new development without first obtaining County approval, or who fails to comply with a stop work order issued under these regulations shall be deemed to be in violation of this ordinance and subject to a civil penalty. 1. Amount of Penalty The penalty shall not be less than $ 50.00 or exceed $_100.00 for each site per day Each day of continued violation or repeated violation shall constitute a separate violation. 2. Aiding and Abetting. Any person who, through an act of commission or omission, aids or abets in the violation shall be considered to have committed a violation for the purposes of the civil penalty. 3. Notice of Penalty. A civil penalty shall be imposed by a notice in writing, either by certified mail with return receipt requested or by personal service, to the person incurring the same from the County. The notice shall describe the violation, approximate the date(s) of violation, and shall order the acts constituting the violation to cease and desist, and, in appropriate cases, require necessary corrective action within a specified time. 4. Application for Remission or Mitigation Any person incurring a penalty may apply in writing within 10 business days of receipt of the penalty to the County Public Works Director for remission or mitigation of such penalty. Upon receipt of the application, the County Public Works Director may remit or mitigate the penalty only upon a demonstration of extraordinary circumstances, such as the presence of information or factors not considered in setting the original penalty The decision may be appealed to the Board of County Commissioners within 10 business days of the decision. 5. Appeal of Civil Penalty. Persons incurring a penalty imposed by the Director may appeal in writing within 10 business days of the receipt of the penalty to the Board of Mason County Commissioners The Commissioner's decision may be appealed to the Mason County Superior Court within 10 business days of the decision. 10.3.1 Penalties due Penalties imposed under this Section shall become due and payable 30 days after receiving it unless application for remission or mitigation is made or an appeal is filed. Whenever an application for remission or mitigation is made, penalties shall become due and payable 30 days after the receipt of the decision regarding the remission or mitigation Whenever an appeal of a penalty is filed, the penalty shall become due and payable after all review proceedings and a final decision has been issued confirming all or part of the penalty If the amount of a penalty owed the County is not paid within the time specified, the County shall take actions necessary to recover such penalty. 19 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE 10.3.2 Penalty recovered Penalties recovered shall be paid to a fund established by the Board of Mason County Commissioners, dedicated to enforcement, education, and/or enhancement of the stomnwater management program. ARTICLE XI: EXCEPTIONS 11.1 Right of appeal All actions of the Director shall be final and conclusive, unless within 10 business days of the date of the Director's action, the original applicant or an adverse party gives written notice of appeal to the Board of Mason County Commissioners for review of the actions. 11.2 Findings of fact Exceptions to Minimum Requirements may be granted prior to permit approval and construction. An exception may be granted following a public hearing, provided that a written finding of fact is prepared, that addresses the following: 1. The exception provides equivalent environmental protection and is in the overriding public interest; and that the objectives of safety, function, environmental protection and facility maintenance, based upon sound engineering, are fully met, 2. That there are special physical circumstances or conditions affecting the property such that the strict application of these provisions would deprive the applicant of all reasonable use of the parcel of land in question, and every effort to find creative ways to meet the intent of the minimum standards has been made; 3. That the granting of the exception will not be detrimental to the public health and welfare, nor injurious to other properties in the vicinity and/or downstream, and to the quality of waters of the state and 4. The exception is the least possible exception that could be granted to comply with the intent of the Minimum Requirements. 11.3 Prior approval Any exception shall be approved prior to permit approval and construction. 11.4 Duration of exception Exceptions granted shall be valid for 2 years, unless granted for a shorter period. 20 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE 11.5 Board of appeals After a public hearing and establishing "Findings of Facts', the Board of Mason County Commissioners may grant an exception from the requirements of this Ordinance. In granting any exception, the Board of Mason County Commissioners may prescribe conditions that are deemed necessary or desirable for the public interest. The Board of Mason County Commissioners, at its discretion, may delegate this responsibility to a Hearing Examiner. ARTICLE XII: SEVERABILITY If any provision of this Ordinance or its application to any person, entity, or circumstance is held invalid, the remainder of this Ordinance or the application of the provision to other persons, entities, or circumstances shall not be affected. APPENDIX "A": DEFINITIONS A.1 2005 Department of Ecology Stormwater Management Manual for Western Washington For the purposes of this Ordinance the definitions in the 2005 Department of Ecology Stormwater Management Manual for Western Washington shall apply to areas indicated in Article III of this Ordinance They are provided for reference and use with the 2005 Manual. They shall be superseded by any other definitions for these terms adopted by ordinance unless they are defined in.a Washington State WAC or RCW or are used and defined as part of the Minimum Requirements for all new development and redevelopment In addition to the definitions in the Department of Ecology 2005 Stormwater Management Manual for Western Washington, the following definitions also apply: 1. "2005 Manual" "Stormwater Manual" means the 2005 edition of Washington State Ecology's Stormwater Management Manual for Western Washington. The Manual as prepared by Ecology, contains BMP's to prevent, control or treat pollution in stormwater and reduce other stormwater- related impacts to waters of the State. The Stormwater Manual is intended to provide guidance on measures necessary in western Washington to control the quantity and quality of stormwater runoff from new development and redevelopment 2. "Approval" means the proposed work or completed work conforms to this Ordinance in the opinion of the Director. 3. "Director" see Chapter 14.46, for Director responsibilities. 4. "Ecology" means the Washington State Department of Ecology. 5. "Grade" means the slope of a road, channel, or natural ground The finished surface of a canal bed, roadbed, top of embankment, or bottom of excavation; any surface prepared for the support of 21 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE construction such as paving or the laying of a conduit A. Existing Grade. The grade prior to grading. B Rough Grade The stage at which the grade approximately conforms to the approved plan. C. Finish Grade. The final grade of the site, which conforms to the approved plan. A.2 1992 Department of Ecology Stormwater Management Manual for the Puget Sound Basin For the purposes of this Ordinance the definitions in the Department of Ecology 1992 Stormwater Management Manual for the Puget Sound Basin shall apply to areas indicated in Article VII of this Ordinance They are provided for reference and use with the 1992 Manual. They shall be superseded by any other definitions for these terms adopted by ordinance unless they are defined in a Washington State WAC or RCW. In addition to the definitions in the Department of Ecology 1992 Stormwater Management Manual for the Puget Sound Basin, the following definitions shall apply: 1. "1992 Manual" means the 1992 edition of Washington State Ecology's Stormwater Management Manual for the Puget Sound Basin The Manual is adopted by reference with the exception of Vol. 1, Chapter 2. which is addressed in Section 14.48.100 of this chapter. Other terms frequently used to mean `the Manual ' include* the PSWQA Manual, and the Technical Manual 2. "Approval" means the proposed work or completed work confoiius to this Ordinance in the opinion of the Director. 3. "Civil Engineer" means a professional engineer licensed in the State of Washington in Civil Engineering. 4. "Director" means the Mason County Public Works Director or a designee who shall administer this Ordinance, which cover the application of the 1992 Manual. The Director of Utilities and Waste Management has the responsibility to administer the Stoun and Surface Water Utility. For application of the 2005 Manual, which is covered by Chapter 14.46. 5. "Ecology" means the Washington State Department of Ecology. 6. "Grade" means the slope of a road, channel, or natural ground. The finished surface of a canal bed, roadbed, top of embankment, or bottom of excavation; any surface prepared for the support of construction such as paving or the laying of a conduit. A. Existing Grade. The grade prior to grading. B. Rough Grade The stage at which the grade approximately conforms to the approved plan. 22 MASON COUNTY STORMWATER MANAGEMENT ORDINANCE C. Finish Grade. The final grade of the site, which conforms to the approved plan. 7. (To) "Grade" means to finish the surface of a canal bed, roadbed, top of embankment or bottom of excavation. 8 "Large Parcel hrosion and Sediment Control Plan" or "Large Parcel ESC Plan" means a plan to implement BMPs to control pollution generated during land disturbing activity. 9. "Permanent Stormwater Quality Control (PSQC) Plan" means a plan, which includes permanent BMPs for the control of pollution from stormwater runoff after construction and/or land disturbing activity has been completed. For small sites, this requirement is met by implementing a Small Parcel Erosion and Sediment Control Plan. Guidance on preparing a PSQC Plan is contained in the 1992 Manual. 10. "Project Engineer" means, the proponent's Engineer or Engineer's representative who directly supervises the engineering and administration of a construction project. 11. "Regional retention/detention system" means a stormwater quantity control structure designed to correct existing excess surface water runoff problems of a basin or sub -basin The area downstream has been previously identified as having existing or predicted significant and regional flooding and/or erosion problems. This term is also used when a detention facility is used to detain stormwater runoff from a number of different businesses, developments or areas within a catchment 12. "Stormwater Site Plan' means a plan, which includes an Erosion and Sediment Control (ESC) Plan and/or a Permanent Stormwater Quality Control Plan (PSQCP). For small sites (less than two thousand square feet of new imperviousness) this plan requirement is satisfied with a Small Parcel Erosion and Sediment Control Plan. For residential sites creating two thousand square feet or more of new impervious surfaces, a small parcel erosion and sediment (ESC) control plan, and residential site improvement plan (including a written description of the proposed development), will be required to be submitted for county review and approval. Guidance on preparing a Stormwater Site Plan is contained in the 1992 Manual or is available from Public Works. 23 ADO? A !S r 0 o MASON COUP TY S TORMWATER MANAGEMENT ORDINANCE this % 67 � day of \Cf h e , 2008 )20cfcld--0-) EBECCA S . ROG IH RS, Clerk of the Board APPROV W = TO .PO Proecuto�; BOAR') OF COS : COMVISSIOX 1ERS MASON COUN Y, 1 ST JiNGTON cts447-- SDI[ )H;1LDO` Chair dit, I 1 ,YWDA RING EM SON, Commissioner R 1 SS GAT LAGH - i, Commissioner