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03297 - Technical Information Report
.. _� BAIMA & HOLMBERG INC. TECHNICAL INFORMATION REPORT for '' Baxter Meadows 2 December 14, 2005 �xUPE �Y �-�� °� wAS�I���� ��� �o� � � d � �s � fe � � 11332 � ���'���'1STER� �'�v �S`��IONAL �G1 EkPIREs 11;'30;%06 Baima & Holmberg, Inc. Job No. 584-010 Prepared For John Mastandrea 2411 S 248th, Unit D-16 Kent,WA 98032 c_1�;,_:_ +z � _.�.�;_;,; = ��: �/� , r DEC2p � � �. �y�'�/� '.��1r� ....�.e,�, ' 1'.. �•..�-: 329� 100 FRONT STREET SOUTH • ISSAQUAH • WASHINGTON • 98027-3817 • (425) 392-0250 • (425) 391-3055 �.z�v�rns sHoi..Lzc1Ho� �ir�Hzv�z���a zz .c�ozs.��s . . ,, . Project Overview This project involves the development of a 0.78-acre parcel into 5 single- family lots. The project is located at the west end of NE 18`" Circle, a gra�el road that is being paved and widened with the Baxter Meadows project (immediately east of this project). The site is about 2 blocks west of Duvall Avenue NE, in the Renton Highlands area. The site is underlain with ����.j�'I�V\��i�ii ��I�IC� ���1� ( ���U:l� i�V�l'1� �I��1- �Ul�j !� ?�iil� (1�.��i �lll�;.��1� i��! IIIiI�CI��lil+�ll. E�sting and/or Drainage Controls Under Construc t i��n As mentioned above, a CB/pipe storm system along the NE 1�`'' Lircic: w��i�r construction with the Baxter Meadows project that will provide conveyanc� and water quality control for this project (Baater Meadows II). Analysis uTr_#��� a plan change for Ba�er meadows was performed demonstrating thi � ' ' is not required for either Baxter Meadows or Ba�er Meadows II (t} individua10Q100's aze less than 0.5-cfs). Per City of Renton appro� (approval letter dated March 30, 2005), the water quality control for b� projects will be provided in a single wet tank to be constructed with B�te� Meadows. The wet tank was sized for both projects using the 1990 KCSVv ll` (1,799-cf calculated for both). As required by the City of Renton approval, th� wet tank size was increased by 30% (2,339-cf required volume). This is being provided in an 83' of 72"pipe. Proposed Drainage Controls This system was approved to provide both conveyance and water quality control for both Ba�er Meadows and Baxter Meadows II and is under construction. Additional drainage control for Baxter Meadows II will be limited to CB/pipe construction on the Baxter Meadows II road extension of NE 18�'Circle and roofdrain hookups. � y � � E,q • ..�_. .-�-�, .-,. � O z � 5 ,� 20 I � �_.. . .=� I SCALE 1� _ � STA. 6t24 _ I —END q1R8 T/1PER , .._. ........:...... �..., � —El� 6'S10EM'MJ( RANP STJI 6t42. 191T —7RANSt10N 70 hoCKOVED C8 iYPE i EDCE q/TfFR ��.� ��T 36' PUBLIC �+��•r RIGHT-OF- Y DEDICATION a S8T43'14'E 2i0.0 ' �: --� - - - u+w � — -�- i � --- - -- -- ---- �-��,�.� � --_ :.���?` �_ -_--_*--` _�-=s- - - -_ � ,� � „_5 .o.sm��.�. ,�- � . � 18TH (`TR('; _ � 4 N I I { � ! . - � j-L----�- � ---- a5•.._� -`s�+"t4_�z .. � . A N � ! � � �' � s'� � /" � �1�` -- __ _ — �---_ 10.AF-t2�St#�0.5Q� i N � I - Nv'. � . �i _ .� � �..� ''� / ' pi `\� A ' . ... M ROVAIE I � 1 I \ j ' �/y`: �S . .� StA. 5+.. � t��LO .2 33 1 � � �F { i i /�Y 7E�E _-9(�N O '- 1 �� iFf T OF LOiS 4 ��� � I i .� __� R S 1c�CY Wf.l,� j .. . __ -- -. VQIIq,.ES .. � - � n � f � F a --------- �Tj � z r , �g p /I 3' � i 2 i � `-� � � � � ' � � L O T 13 ��` ��� ; � � � � "� � � , i � � rT , � � ---- - �`' J � � __ _--- t� � 23.�0 4�3 � f , 4 5 � 3 " � � N 422 � ? � ,`,�� � � P \ N ' � . � i g � i f24 � 423 �`L� 422 NST47'48'W 210_03' � I . .._. ., ,.,_. . .,-,. .=... , , .._. :. ..,_, . .,-., .-. . � � I � , Site Plan MGR-30�2005 14;59 CITY �,RENTON 425 430 ?231 P.01 . . ,. . C�'�`'S�" ���' REN'T�l\T � . ' �. � II . � , , - ,'' •- � Plaaniag/Buildir�Pub2icWorks pepartment -• ..� . � . � . ' . Kethy Keoilca-W6cela,Msyor • • �'ireg,�Zi[wcrman RE.,AdminSstr�tor; , - � . I .• � = ' March 3Q,2005� '. � � � � . . , � w�iiam Hoimber�,P.E. . ' � - , ;.� � I . . Baima&Holmberg Ync. . . . . , . lOQ Prant Street South ' , • • - Issac�uah,'WA 98027-3817 , , . • : . � � , Su6ject: �axtex Meadow 2 Drainage St�ndards . � ' ' . , - � � Dear,Nir.Holrt�berg:� - ; � - � ,.. , . , � . The City of Renton�reviewed yaur r�quest to reconsider ch�determin,�ion of im�osing .. . . ' . �. • the 1998 King Countp Design Manu�i standazds for the five Iat singlc-family short plat , .' ' � '. � known as Baxter Meadow 2. This is a shart pIat af�roperty eztendin;from a propased.� , � •� �� ' cul-dc=sac Co be built with the Baxter Meadow Short Plat cu�rently ur.ier review for � . '. .. i � � constiuction. The previous short plat was designed under the 1990 m�nual,did not have � , � to providc detendon, a�d is installing a water quality vaul�. '�e City 3f Renton will • . ' , agree to impose the standards 8�s set by the'1990 KCSWDIV�with two conditions. - • � ' F'inancial hardship is not a justification or factor of determinadon of��hich di'ainage � �,' , control standatd is acpplied to a developing prvperty,.Such factars•as ;mount of . •� addirional CFS,downstream capacity,existin�drainage issues, and p:oximity of � ' ' wetlands or streams can tdp a site ipto a higher level of pratection or lesign. $y map, , ; . ,• this site should be�under the�1998 manual,Leve11, But, as the calcut �tions provided by � : � the engineer show that under the 1990 manua],no retention is require�, the City vf I�enton . ,� � � may elacc to a�ply the 1990 msnuat as the cQdified standard. . � , � There has been observed at�ding water in this area vtd there is some questicin�n the '_ ' . downstre�m capacity being able to handle much additional water with�ut dama�e to . . � � '. downstream properties. The proposed development is also part of the Honey Creek , " � , drainage basin. Additional cvnditions are common ia these bases. � ' � � . � 'iherefore, the use pf the 1990 King Cou�ty]�esign Manual as the sta�.dard of design and �,_, � � �� � . exempUions is approved`with the fotlowing two conditions: , � . � ' , ' ' � ,•,' : _ �1. Redesign the starm water facilities for Ba�ct�r Meadow short p at to provide a , singIe system-to aceommodate and provide water quality for a:l run-off,from t�ath the Qrigiz►'al �axter Meadow short plat and the pcoposed Baxte: Meadow 2 short . , . plac, � � � . . , , • 2. The syst�m s�rving the two short plats shall be c�esigned witlt � n addit�ona130°l0 • _ . safety factor in�apacity for the water quality vault. The reteas;rate�shall be - adjusted accprdingly. � • . , . , � ' 1055 South Grgdy Way-RcnCon,Washington 98055 , ' � E N 1. V N, ` . ' . �mv,na,a.r.,..mtr.a w✓..a.w..�.....�a..�u�o�...,......._�..�_ ' A F7 P_n 0 O F 'I"H E C il k V II ' . � MRR-30-2005 14�59 CITY OF REMTON.- � - 425 430 7231 P.02. • . • • . • • ' � . � . -•' . : ' ' Construction of the system will be required pxior to recording either s �orf pla� ,Yt will be , � ' ' ''• . • . � - more cost effective to design and construct one system for both short �lats, and I applaud ' • " . . � . . • •, . : yaur foresigfrt. . . . � . . '• � � .- � � ; � � Baxter MeadQw 2 sht�rt plat has only had a pre=application me�ting sc f�r, so no formal ' ' . : • � ' � application exists y�t to attach these condirions. Tbese requirements�ri�l appear as • . . ' , conditions for approval whcn this division reviews the application. . • ' .' � �. . If yov have any fqrther questions,plcase do not hesitate to contact Ar�eta Henninger at ' ' �, � � . �,' � ' ' 425-430-7298. . . " . . ' �'� • . Sincez�ely' - � ' , � .: . '. •. , �� . � • � � � . . ' '•, - . , ''11' 1 1�"'�-' . � ' : •' : . � � � Kayre �ttrick • � ' � � � ' . ' . � I7evelapment Engineering Supervisor , � ' � � � � � • : � �. - "'Public QVorks�nspe�tions�Permits, , � • • .�, ' " . ' . • Devetopment 3ervices Aivision • • • ' . • � • "� '. C�C:, Arnctsi Hc�inger, , � " • ; , - .. � ,� � '� •.' . Jill Hall . � . , , ' • ' ' ' _ . Pat Miller . • - ' • , • . ' , . , • • • . , . . � - .� . � � � � , : . . . . . .,� . .` . . . . , . . ' ' ' ' . , ' ' ' . , • ' , •,' ' .' ' , • ' ' . • . , • ,' . . . , , �.� • , , . � • . . , • _ , . • , _ . . , �. � � • • . ' • ' , ' • . • ' ' ' ••�' . . � � . � . , ' : ' • - � , .. • � TOTAL P.02 SIS.�.'Zb'Hd' �.LIS-33CJ III .L�IOIZ��S BAIMA & HOLMBERG INC. DRAINAGE REPORT � for li, Baxter Meadows 2 May 3, 2005 c��U PE �. Q���F wAs�f O� N�� �� � a � � x � � - � ��0� �1�332 � �4 'cG ,��R,�"�s1 �"SIONAL �'1_ EXPIRES 11/30/06 � Baima & Holmberg,Inc. Job No. 584-01Q Prepared For John Mastandrea 2411 S 248th, Unit D-16 Kent,WA 98032 100 FRONT STREET SOUTH • ISSAQUAH • WASHINGTON • 98027-3817 • (425) 392-0250 • (425)391-3055 Project Overview This project involves the development of a 0.78-acre pazcel into 5 single- family lots. The project is located at the west end of NE 18�Circle, a gravel road that is being paved and widened with the Baxter Meadows project (immediately east of this project). The site is about 2 blocks west of Duvall Avenue NE, in the Renton Highlands area. The site is underlain with . Alderwood Series soil(loam over till), and is thus not suitable for infiltration. Downstream Drai.nage The area along the NE 18�'Circle has a CB/pipe storm system under construction with the Baxter Meadows project that will provide conveyance and water quality control for this project (Baxter Meadows II) as well. Presently, runoff from this site sheet flows west and south with the southery flows draining across adjacent properties, collecting in a ditch/pipe storm system in the next street south, SE 107th Street. The 107th ditch drains to along the west side of Duvall Avenue NE. This ditch flows south, crossing through a few 12" driveway/roadway culvert before entering an 18" closed storm system at SE 107th Place. This storm system continues south to the intersection of NE Sunset Blvd with Duvall. Flows continue west through the Sunset storm system. There are no obvious problems along this downstream drainageway. The drainage system under constcuction in NE 18'�Circle will discha.rge into the ditch along the west side of Duvall Avenue NE. Existing and/or Drainage Controls Under Constzuction As mentioned above, a CB/pipe storm system along the NE 18�'Circle under construction with the Baxter Meadows project that will provide conveyance and water quality control for this project (Baxter Meadows In. Analysis under a plan change for Baxter meadows was performed demonstrating that detention is not required for either Baxter Meadows or Baxter Meadows II (the individual�Q 100's are less than 0.5-cfs). Per City of Renton approval (approval letter dated March 30, 2005), the water quality control for both projects will be provided in a single wet tank to be constructed with Baxter Meadows. The wet tank was sized for both projects using the 1990 KCSWDM (1,799-cf calculated for both). As required by the City of Renton approval, the wet tank size was increased by 30% 2 339-cf required volume). This is being provided in an 83' of 72" pipe. Proposed Drai.nage Controls This system was approved to provide both conveyance and water quality control for both Baxter Meadows and Baxter Meadows II and is under construction. Additional drainage control for Baxter Meadows II will be limited to CB/pipe construction on the Baxter Meadows II road extension of NE 18�'Circle and roofdrain hookups. �� '°'°`�`� �� � � � � �' � � 3 � . 1 3I � � �s �` I7 � 16 19 20=- 2t 22 2 � o � � gp.�4 - - - - _� �.17 7 . � �-a H � � r J.. � ^�����rr r , . 1r`f. "'_'__. _,_,L,,,,:,_ _._..... ... _ ._._. ...— B� , r—, , .� �__----- , , � : ,a___ � � _ , _ �� � �,; • =T" � ~ � ; � , � ' �� ,,� ► i � � r - . r�. � . fi . 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Y '�' . , . z ''' .�`� S n., .•. 1 � ��� 5 - 3 �6 ' . �a. �o �� Z1��5 �s.a2 �, .•. ,•. � ��aN 34_8_,_,_..r...,.Ci�R (20 L-�� � !23 a� � 1�� RE � � 2} a .; ,., t � — � � 2 6 �' �'• � ,, � , ,,. � i S P 89•87 �s�r ,;. , . . .,. � �- . , .•. . �� '�' .�. . � •�� n, u �22 y . . � 6 .'. .. .•� � O a ` .•. � � . �" � DUV"VNSTREAM � :': � � . � � � �� � o ... ... . M DRAINAGE MAP � a�--�o •:. ;. � � 121 , ' 4 ; 1" = 100' � � . :. . . . l�'1CiF1 VUl�1LL{, � � a�rbv � v� ... � King �ount� �,'i��� • � iMa Print Pa e � 2 87t&U3 - � � 3� 1 109i 5 �! � �i Ey3T}�SI�� � +qTGG N Ec��3T !04 78 877006 �TI_ � � 7 _ . r J�� _ -- - � k�h7Et152 �t�i7tSUf`i26��OB � ' 1 2� 106d]G t4 =i,-y �:f 2 �u' 3 � :. �1 z1 t a �' � ,�i ,r' �7 u� A � cy f 7T�k'13 - ;:?7't�• aG9?At)s -- ,L�+y�r � - A --- — NE_1b?A� � �,�r ���'C '77 _ - at�,• SI 3;iici� � _ 1bf.�8Q • ��i� `rv 5't&&Tt�tttXl. c, ,� t �53TCi RA , �� T � 7 ` - - 3295abE51 :� &?JL 2 0$ /,' $ 107 2T, TcQ2 ' �fi4 � �+ � ' ^f�t#� ZT 7 ,-}; g4 � S##i3'7flCK�d1 n �� 2 7'i'� _' � � � N E�TTii�� y 2T T7�'.,[; §3 4 � � T(l13 3tk t 27•�^ � 35�i1i�06ES�6 y np� ,�{y 2� 77QC� 7G 03S - T731000 `� j � .,._ _ _ o�T:s?t ''. - --- . -:.t=.�'a: . _ - {.. 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F,Fa�1 � C8-Cainosr�r B� },r Forast!'�aduc�on 0�� e �,u� ■ Rs•a�a� �u�naary [u.is,�:,�-�,a��:r�3�� S a.o�e �s AgfioURuralprOdtlUiGADistliel r'tA�3=iLr�h�.a+aDUperS�ea 1-t,6.�rat 6awndary � �.io.wma�.aaoup�inarn� � cx�,s � Urh�n f�wth Area Le►e ���"�.�'"eou�s�es r,�f Topa ConSours(5R� � �-t-�.��u�.� Lakas atai ta�ge i�ees R•4��'C�.4 t7U ptr 3se � t�ddesdeoct 7�e �.s.ar�e�s:a au ptr� � Pa�W �,s,�.aoup��� .: ������ eT<12.Re�dsfat.l2tYJA�sc�t Znnirf�Labe�s p-�a.�aideAme,�a av pa�xre �'�� ■ A-2t��de#.2l fYJ�r naz _-__ A=HI-hg�3rat.are[}il�k7 a�+es ■ �i$=R�id.4a a'hl p�a..tt l�aF �r+± information induded on this map has been compaed by Kirg County sta(f from a variety of sources and is subjed to change w�hout notice. County makes ra represer�tions or wanar►ties.express or inpfied,as to accuracy.oompfeteness,timel��ess,or rights to the use of such formation_K�g County sha�rwt be Fable for arry general,�1,ind�rec�iicidertal,or oonsequential damages iidudirg,but not 6mited to, st reve�ues or bst profits resulting from the use or misuse of the informatan contained on fhis map./4ry sale of this map or informatan on ' map is protubited except wrdten permissan of K�ng Co�ty. http://www5.metrokc.gov/servledcom.esri.esrimap.Esrimap?ServiceName=overview&Clien... 9I4/2003 SECTION iv RETENTION/DETENTION ANALYSIS AND D ESI GN Mt�?-30-2�5 14�59 CITY OF RENT�I 425 430 7231 P.01 . ., � . � ��'I"S�' ���' REN'Tl'�N � : � ". �. ,'' '- „u Plannin�/Buildir�PublicWorks Department �, � ..� , ' • ICethy Kcoika-Whaler,May�or . - . G['eSp Zil lmormao P.E.,Adm9nistY�tor; ' , • ' � , .- �� � Mazch 3Q,2005- '. � � � . . � Willi2�n Holmberg,P�. . ' • � .�� � ` � � �sima.&�-iolmberg Ync. , � • , � _ 100 Pront Street Svuth ' • , .' �. ' Issaquah,WA 9802'1-3817 . , . • ' �, �• , Subject: Baxtex Meadow 2 Drainage St�tdards � � . . �� � Dear•Mr. Holmberg:� , ; , . � � . '�t�e City of Renton�reviewed your request to reconsider the detemain,.tion of impasing . . . � ' . �. • the 1998 King County Design Manual standards for the five lot si�nglf -family short plat _ .� ' � '. � known as Baxter Meedow 2. This is a shori plat of property extendin ;from a proposed� , ; �� �� � cul-de=sac Co be built with the Ba�cter Meadow Short P'lat cun�enfly nr.3er review for � . �. . � construction. The previous short plat was designed under the 1990 m mual,did not have � , , • to provide detention, and is installing a water quality vaul� 'rtie City �f Renton will • . ' . agree to impose the standards as set by the'1990 KCSWDIV�with two conditiotls. � • � F'mancial hardship is not a justi�cation or factor of determinadon of� �hich drainage � �,' . ,� control standard is applied to a developing property,,Swch factors•as ; mount of - �� addirional CFS, downstream capacity,existing drainage issues, and p:ox'imity of � � wedands or streams c.an trip a site into a higher level of protection ar lesign. �y map, , ; . ,, this site should be�tinder the�199$manual,Leve11, B�rt, as the calcuI �tions provided by : � the engineer show that under the 1990 manua�no retention is requi�rec, the City of Renton . � � may elec�to apply the 1990 maauat as the codified st�ndard. . � , There has been abserved sta�nding water in this area and there is some question on the '_ � , downstreara capacity being able to handle mueh additional water with�ut dama�e to . . �� � '. downstream pmpecties. The proposed development is also part of the Honey Creek , ' , � drainage basin. Additional condi�ons are common in these�asEs. � ' � � . ' � . 'T[aerefore, the use of the 1990 King Counry Design Manual as the sta�,dard of design and �. , � "� . exemptions is approved�with the following two conditions: , � . � ' ' ' ,•, ' . •1. Redesign the storm water facilities for Baxter Meadow short p at to provide a . single system•to aocommadate and provide water quality for a:I �un-off,from both the arigim'al �axter Meadow short p]at and the p�posed Baxte: Meadow 2 short . . , plat, � � ' � . . , � �. The system serving the two short plats shall be designed with s n addit�onal 30°b � . , safety factor in�apacity for the water quality vault. The releas ;z�ate�shall be • . adjusted accprdingly. � . . . . ', , ' ' . � • " . , - ' 1055 South Grady Way-Renron,Washington 98055 , ' � E N � � N, ` � . , ' . �TiYm m�wrr.r.ed.,a.vwc.on...�sw...�a..�onoc.,.,....».....�__ ' A H P_A D O F 'f 73 E C U it V E ' . - MAR-3�-2005 14�59 CITY OF RENTDN 425 430 7231 P.�2 • . • - - � , � ' � . � . . . • : ' ' Construction of the system will be required priar to�cording exther s ►ort pla� ,Yt wilX be , � ' � '� , • . � � more cost effective to design and construct one system for both short �lats, and I applaud ' • � ' . . , . , . . �, . : yaur foresight. . , . . � , _- � � ; � � Baxter Meadpw 2 shart plat h�s only had a pr�applicadon meeting sc f�r, so�nd formal ' ' . � � � ' � ' . � application exists y�t ta attach these condirions. These requirements � ri�l appear as • . � � , i� � , conditions for aQproval when this division reviews the appIication. . • ' .� � �. . I, / If you have any fprther questions,please do not hesitate to contact Ar ►eta Henninger at ' ' �, � � I��, , 4?5-430-7298. � . � , , - . . ', °� • , Sincenely; � � , � �,' . ' �' ' . . - ' , '�l• �1 1�� � - ' � : .,� : ., - � Kay� "ttrick � � . , , � i. . ' . � I3eveldpment Engineering Supervisor , � ' � � � ' : � : - �. � "� Pulilic�Vorks T�spe�tions&Permits, � . .. . � � � Development Services Division � - � ' , , ' . ' � ,. 'A ". � CC:. Amcta Hc�minga, . � ' ' ,- , - ,. ,• � '� ',' . JillHall , � , . . • � . " . ' Pat Miller , � • ' . � • ,,, . ' , • , • • • , . , . . . : . , . . • ,•� • • , . , , • ' . ; . . , _ , . . . . • • � r , - . • . •,- • ; ' ' ; � . . ' • ' . . �.�: ' , , . + . • . . . ' • . • . • •. , ' • ' .•.' . TOTAL P.02 R/D Analysis and Water Quality Design for Bazter Meadows and Bazter Meadows II (1990 KCSWDM) The following analysis shows that detention is not required for either Baxter Meadows or Baxter Meadows II(the individual�Ql�'s are less than 0.5-cfs). Per City of Renton approval(approval letter dated March 30, 2005), the water quality control for both projects will be provided in a single wet tank to be constructed with Baxter Meadows. The wet tank was sized for both projects using the 1990 KCSWDM(1,799-cf calculated for both). As required by the City of Renton approval, the wet tank size was increased by 30%(2,339-cf required volume). This will be provided in a 83' of 72" pipe. • JOB ��� � i � ' BAIMA & HOLMBERG, INC. SHEETNO. OF 100 Front Steet South ISSAQUAH WASHINGTON 98027-3817 CALCUU1iEDBY TI�' pA,� � Z�yIfJ 7z_ (425) 392-0250 FAX (425) 391-3055 —�' y CHECKED BY DATE SCALE _.... _ _ ___ ___. _. __ __.... .. _ _ _ __ _ _ ; ._ ��'� ___ p : ��S t Gc.1V _ ����j. __�=GaS��Yvl _ . -... �.._- _ , � ; ; _ __.�_.._..:. , __. __ 't��- U��"f.���tN.� ��L_`�'� _ _ _ _ _ y - _ _ __ _. __ .. ____ _ __ _ . 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TYPE-lA DISTRIBUTION ******************** � � 1� ********* 100-YEAR 24-HOUR STORM **** 3.90" TOTAL PRECIP. ********* �V v ---------------------------------------------------------------------- DATA PRINT-OUT: AREA(ACRES) PERVIOUS IMPERVIOUS TC(MINUTES) A CN A CN .8 .6 85.0 .1 89.0 10.0 pEAK-Q{CFS) T-PEAK(HRS) VOL(CU-FT) .47 7.83 6773 ---------------------------------------------------------------------- ******************** S.C.S. TYPE-1A DISTRIBUTION ******************** ********* 100-YEAR 24-HOUR STORM **** 3.90" TOTAL PRECIP. ********* ------------------------------------------------------------------- DATA PRINT-OUT: AREA(ACRES} PERVIOUS IMPERVIOUS TC{MINUTES) A CN A CN .8 .2 86.0 .6 98.0 5.0 PEAK-Q(CFS) T-PERK(HRS) VOL{CU-ET) .71 7.67 9323 Existing Conditions SBUH Peaks � /Q � ------------------------------------------�_,_�7� ----- M,�__ I�u�s ******************** S.C.S. TYPE-lA DISTRIBUTION ******************** ********* 100-YEAR 24-HOIIR STORM **** 3.90^ TOTAL PRECIP. ********* ---------------------------------------------------------------------- DATA PRINT-OUT: AREA(ACRES} PERVIOUS IMPERVIOUS TC(MINUTES) � A CN A CN ---__.__.-_._. _�._ _ , __. _ . ,-_, ,,, : ;_;_ _ -- -- .� Water Quality Wettank Volume, Sized for Baxter Meadows 1 and 2 ---------------------------------------------------------------------- **********�********* S.C.S. TYPE-lA DISTRIBUTION ******************** ********* 1-YEAR 24-HOUR STORM **** .67" TOTAL PRECIP. ********* ---------------------------------------------------------------------- ENTER: A(PERV) , CN(PERV) , A(IMPERV) , CN(IMPERV) , TC FOR BASIN NO. 1 .6 86.0 1.0 98.0 5.0 DATA PRINT-OUT: _ _ .-- , __ _ _ ---- ----��i�c� - �E��t�� _ �ri�����o�� _ �c{-�il�ir�s=)-- - A CN A CN 1.5 .6 86.0 1.0 98.0 5.0 PEAK-Q(CFS) T-PEAK(HRS) VOL(CU-FT) .13 7.67 1799 SECTI O N V CONVEYANCE SYSTEMS ANALYSIS AND D ESI GN S�CTION VI SPECIAL REFORTS AND STUDIES w-;��:�_� ?I�' ��zHH�a .�s.z�nv�v�to� ciH� �is�s zzn. .Kors.��s SECTION VIII �i �9 ����-^' ��71�y � F �`, I SECTI O N IX ERUSION/SEDIMENTATION CONTROL DESIGN N A w zz xQo z � v� � W � � � W . � zx H oW � z � � � � � z � w wz o � A qw H HZ p � w Ho � � � zH � w Qz � �o � w � x aH �, � A � aW z ~ � 0 � �n � w sEc-rzorr xz MAINTENANCE AND OPERATIDNS r�IANUAL 11��IA2I�A0 .L��l O�I d I i�i O I.L��S �� , CITY OF RENTON � � Planning/Building/PublicWorks pepartment Kachy Keotker-W heeler, Mayor Gregg Zimmerman P.E.,Administrator March 30, 2005 William Holmberg, P.E. Baima &Holmberg Inc. 100 Front Street South !, Issaquah, WA 98027-3817 I Subject: Baxter Meadow 2 Drainage Standards I�, Dear Mr. Holmberg: �' The City of Renton reviewed your request to reconsider the determination of imposing I! the 1998 King County Design Manual standards for the five lot single-family short plat known as Baxter Meadow 2. This is a short plat of property extending from a proposed � cul-de-sac to be built with the Baxter Meadow Short Plat currently under review for ' construction. The previous short plat was designed under the 1990 manual, did not have to provide deteniion, and is installing a water quality vault. The City of Renton will I agree to impose the standards as set by the 1990 KCSWDM with two conditions. ', Financial hardship is not a justification ar factor of determination of which drainage ' control standard is applied to a developing property. Such factors as amount of ' additional CFS, downstream capacity, existing drainage issues, and proximity of wetlands or streams can trip a site into a higher level of protection or design. By map, this site should be under the 1998 manual, Level 1. But, as the calculations provided by the engineer show that under the 1990 manual no retention is required, the City of Renton may elect to apply the 1990 manual as the codified standard. There has been observed standing water in this area and there is some question on the ' downstream capacity being able to handle much additional water without damage to downstream properties. The proposed development is also part of the Honey Creek drainage basin. Additional conditions are common in these cases. Therefore, the use of the 1990 King County Design Manual as the standard of design and exemptions is approved with the following two conditions: ' 1. Redesign the storm water facilities for Baxter Meadow short plat to provide a single system to accommodate and provide water quality for all run-off from both the original Baxter Meadow short plat and the proposed B�ter Meadow 2 short plat. 2. The system serving the two short plats shall be designed with an additiona130% ' safety factor in capacity for the water quality vault. The release rate shall be ' ac�ju�ted:a�rd�r�gLy._. ' , �I 1055 South Grady Way-Renton,Washington 98055 R E N T O N �This paper contains 50%recycled materiai.30%post consumer -A H E A D O F T H E C U R V E - -- ---.. _ . . _..--- -. . __. .. _-J Construction of the system will be required prior to recording either short plat. It will be more cost effective to design and construct one system for both short plats, and I applaud your foresight. Baxter Meadow 2 short plat has only had a pre-application meeting so far, so no formal application exists yet to attach these conditions. These requirements will appear as conditions for approval when this division reviews the application. If you have any further questions, please do not hesitate to contact Arneta Henninger at 425-430-7298. Sincerely, �� �wl�tll�J Kayre �ttrick Development Engineering Supervisor Public Works Inspections & Permits Development Services Division � ...k. t $`.-:.. . . . .-� .. . ' . �. . �J��� '»'X�,e. } -g � CC: Ameta Henninger �-`� _ ;�. a ��'•'���;:,� ' Jill Hall ,� ;, ,� p '';��q r. . i a Pat Miller �� ,� ��_,: 4� � _ ��,�, ; � ''4 � �� �s ._� ��5; �..- . P�9i T � f fir .' *y�Y . . � a�� �Y . � _ . . - � . .- - �3;� 5:�^'& ... . . .• ��, - � � � ' � . � a:-- 'F�� . . ' - � ' +j� .'�'�'Z't'�- . .• t�.'�i�� . .. . • .- - . . . �' .� � . . •�'�2 Ts'`g` �Y i',e � . � . . x . �. , - _ -- • . . . �'�`� - � r. �, . :x �`z. . �. . � _3�-�� I � 'I � �l/�/���1 ��o��c�� /�c. 1 � ' � �r:'�' Delineation/Mitigation/Restoration/Habitat Creation/Permit Assistance 9505 19th AV@f1U6 S.E. ' � � Suite 106 ; December 19, 2005 Everett, Washington 98208 '� (425) 337-3174 I Fax (425) 337-3045 'I Legend Development Attn: Ray Mawdstey 510 Rainier Ave. Seattle, WA 98144 � RE: Wetland Reconnaissance Report 0.78 Acre Site Located at 11811 Duvall Ave. NE I Renton, WA. I Tax # 5169700154 On October 3, 2005 Wetland Resources Inc. investigated the above described property for the �I� presence of wetlands and streams. No wetlands or streams were found on or within 100 feet of the subject property. The Washington State Identification and Delineation Manual, March 1997 was used as the basis for wetland identification. The City of Renton Environmental I Overlay, Chapter 3 was used as the basis for determining definitions and protection requirements. I The property contains an existing single family residence with surroundin� landscaping, and outbuildings. The western approximate one third of the property is {orested and undeveloped. Immature cottonwood and Douglas fir are the dominate trees species found in the western portion of the parcel. Ve�etation in the understory is dominated by brachen fern, domestic holly, swordfern, domestic ivy, and Himalayan blackberry. This mix of ve�etation is rated as upland. The underlying soils were gravelly loam in texture. brown in color (10YR 3/3) and dry at the time of investigation. These soils are not hydric in nature. A smatl artificial pond was found adjacent to the attached deck on the western side of the house. This pond appeared to be approximately 15 feet by 20 feet in size, artificially created from a non-wetland area for the purpose of raisin� and observing domestic carp (Koi). Artificial wetland amenities that are intentionally created from non-wetland areas are not �z��iiat�d in t�rc S�ate of "v"Jasi�in�ton. This pUnd h�s �een partiatiy iiilzd at tne Lime oT investigation. If I can answer any questions or provide additional information, please contact me directly. Cordially, Wetland Resources, Inc. / , . yl/ William Railton, PWS Principal Wetland Ecolo�ist Wetland Resources, Inc. 1 Critical Area Reconnaissance-Baxter Mdws ll Dec.,19, 2005 WR! #05389