Loading...
HomeMy WebLinkAbout03164 - Technical Information Report - Drainage �. � f�-3��y STORM DRAINAGE REPORT PROPOSED ELLE RAIN PLACE 3316 ANU 3420 NE 17TH PLACE SECTION 4, T. 23 N, R. 5 E. W. NI. RENTON, WASHINGTON 98055 RENTON - LUA-02-047 FOR: PATRICIA L. WILSON 1075 BELLEVUE WAY NE #1_500 BELLEVUE. WA 9800a J U N E, 2003 ���� �, a� ^�Q � �' � � � JOB NO. 719-010-001 3 9470 �� G(i�� • 9F �n �`�' � STER �('7,,� Prepared b ��� �'7��`'��'� y � .._ . .� Touma En ineers DCQl�,�SIz2;o��,�; g �..__r��__d.�_ 6632 S. 191ST PI, Suite E-102 Kent Wa. 98032 PH. 425-2_51-06G� Fax 425-251-0625 F'�_1<`-I 1l.Il-cC:...... � 3 �� y TABLE OF CONTENTS Pa�es I. PROJECT OVERVIEW 1-3 11. CONDITIONS & REQUIREI��IENTS SU(�1(��IARl' �1-� 111. OFF-SITE ANALYSIS ��-8 1V. �LOW CONTROL & WATER Qli��l,l'I'l 9-2i1 V. ('ONVEYANCE SYS'1'En1 ANALI'SIS A�I) UI�:SI(:N 2t-30 VL SPECIAL REPORTS AND STUDIES 31 V11. BASIN AND OTHER COMNIUNITY AREAS 32 VIII OTHER PERNIITS 33 IX. EROSION/SEDII�IEN7'ATION CONTROL DESI(�N 34 X. E30ND Ql1ANTITIES WORKSHEF:'I' 3S X1. 1lAlti`I'E'V.a1VCE & OPERAT101�� 11;1V1�;�1, 36 elle-rain-sd.doc I. PROJECT OVERVIEW This project involves about 1.78 acres in the southeast quarter of Section 4, Township 23 North, Range 5 East W. M. It is bounded on the south by NE 17`h St., with tlie Renton Housing Authority and a 100 foot Puget Sound Power and Light Company transmission right of wayo un the west. To the north and east are larger single family lots, and down the slope to the northeast is Honey Creek. The City of Renton Hearing Examiner, Mr. Fred J. Kaufman on April 29`h 2003 ordered the approval of a 10 lot subdivision based on his published conditions. A sidewalk easement was agreed to by the owner of lot 1 of Honey Creek Park, so that the proposed road and walk cou(d be moved westerly and make lot 11, 60 feet wide. Mr. Neil Watts of the City of Renton said that the developer could proceed with an 11 lot subdivision. The site and project area are hilly with an average downward slope of 12 to 26 percent from south west to northeast. Some steeper slopes of 26%to 32% are located along the northeast portion of the site and areas in the vicinity of lot 1 and 2. Grading for the site will be limited to tl�e right of way, adjacent return slopes, the detention storage area and the appropriate storm drain system access. We plan to collect the surface runoff from the added asphalt surfacing and direct it through a wetvault on the property. The site existing soils as indicated by the King County Soil Survey are Agd (Alderwood), and AmC (Arents). These soils are listed as type"C" glacial till. This soils information is substantiated by the geologist report prepared by Terra Associates. The city is requiring that this site meet the requirements of the King County level 2 flow control. This mea� that the detention and outflow contr�ol device be sized to meet the durations of 50% of the 2-year through the 50 year storm peaks. The outflow will be directed southeasterly along the top of slope, to an outfall constructed with the Rose Short Plat down the slope to Honey Creek. The Rose Short Plat high density polyethylene pipe out fall will be constructed before the Elle Rain Plat storm drainage. REVIEW OF RESOURC�S 1. Vicinity Map 2. King County Soil Survey Mapping. 3. City of Renton Zoning and Subdivision Ordinances Pg. — 1 ELLE-RAIN-SD.D�C ! / �? t �0 i s's,, / i H 8 �� � "r ✓- " w►n`� _ ---- 1 i i • l^ ' 16 � �� _ -�" � �� ti� W � I � � 4 'rZ*�,�o „� � m ~5 ,` t __ �0 111i �--io9�� � , lD _-�Z2"oi it l� iz�n -' " ito � o. a _— _` �- -2 �'� 1�I�S D �� il�� b� � �� S �/�tc�'_ ' � ;1 m �no Z 1� �u • � , O ' � � �!1 ..�ij��f., ` NO 10 J� V• p. � �j �'� 100 a, M �+ � �� .r ya M s� 1�� � 120 � _— 120 _�)o�— 1 a 9 s '� e `� 20 � �s g ie � m� �m —o� 3 5� ���,�}�'�'p-ff,,,.�� �� �:4� � � �.� y �. •_ f a Fp + , m„ "` J� �,. � V!O! Z i0i pd �o�' ` A�• y 2E �v �l. � Io609 Rza4 5� NIS � �. ` 76lL � �'�. s (� 65 S� ir 91 d2 63 � \ CEN.0 ��rzs 1928� . NE m21ST ST °� � � S E �O4 /�'� .-ST �°o [ G53 J� � � 4 / � �$r �399� + bw _ 1,'1 � � � / / � ' ' �t t [ io 9 0 8 �a �� � 5 �; ,Is ,o.lo �o�o �� � �� �C r — iso — � IO d' 1 V �oH � N E Y C R E E K � 13 , �� '2"' �' � '�`� l � 4• ( / � �LI '� :; 1� I A� 1 ��ti � s e.s��2� � � 1S� *,^� �11 7[2/3r � saa �1� 07 � � i6 It �, scAcE ,:i��� � ,�°� a '� S� ,osr � , , , ��, � �'' NRo„ ��`�e� v°, 14 � PL$ � � �� � � °^'E� ��` y e 9� oA. y6 81cK� �F ��, 14�` i __ � � "� G R E E N W A Y � , �be ��s-���� � ,,, � T� � / io z � -• �� � . ,qs� � / N ti �„iosi .. ' i e I / ^ � `(/ 15` ��17 �' a Ac � �,� o � rsi 7i � � � ` � I a �-�g�,a�, i i9 � � � �, �i; I I _ z�a�s -- N `� �t �4��� I . � zz6 rc i� �9 i o�z�0 60 :. s . I (ai3 B/ 2� v T �9 O c RENTON '�3 CORP L/M/TS O ��- I / / �Jq15n � j�t s� a John G Love � ri � I �` fred I L�nde i� i � i .r. �; ,, �j 3 U il=A6co ,�� 'z?9 303 c 16At �' -- I • 9I [ � r[09 I + �2 � e zi 939�6 � �� � 6 � 3 ,�g�, _ �;� s � � L�J � `� a � 8`'"' Proposed � �� \ u � � . F _I— � W �. ,E , `� � 9 Park Q � •�% � -� � ,: / Ty 6, .6� �, _'-� 0 ' I + W � � � O •� \ JJ I O p � � � I � I •, Q � I '^2 3 � �l � � -� N e ° !r o ��� 1 I '- � � � I W _ � a ~ 13 " A� s ° � , . � ^' � , �' o o ' E, I � f�� o ei � ti° , ,� `' � ; e � I�2) �o� ^ .NE ITTN �ST ' ° �ti �, �°� . '�, `� 3 S � s 6a �4i� c� : 7 �dti � `� . � I o b� ("��� �� o h ` �r+ Z � �` ` ,� �SrF}�e' �5--+� Z II `�'3 neB6 � ie� 321i9__ 4A4J� �'�e 50 �o� ,09 ,a.f3: o �se ... ,_. � e S e6 S �oo Bo SS 4 ..� /O�' � W � T��3 � � q �t /73 T[ 57 T! �l • T[/S! T[ �IO 7� 97 �I �� � � tt 215 � NOrman L IetZ .f'�,�� � y Owan R e �t is � ^' � fl- � Johnson `� I I � a � � r�� r�, f'�. RR� o� � � N e � ^ Q o 1 �� 72 - -� pi��i 2 e �o � 3 � ` — . ; 96 � � � w p �' t I � �3 � i i� r' Z �, � X, ,- ,� � N� � � g = --�N � L�] ,� _---- e, ' ��__----- � -�--_-,._ .4� ��. � �. 9a�. hr � ----$=suNSEr �---�--- � T t.z69 � �T.[.97 0 �,;� �y �"-`----�--_BL�/0 • �� i � ,� � i ,s�as ,:s ,...... �*,i � , '-r-� ,i � F w —` �24.I� __ ... 4 . r o l � ��•�J — `-- �� � rr ,�,i 1 Tl ?07 1 � � � � T� 2p � � ___ ;, o ? �,/' � 1 `� . — Z ; ,_-_ ` �„W ,� ��n, , -- -- ;\ � �,/ � � � c -- -- '-- l.:J � ,��� I '' J � �� Earl McLou9hlin I j ��__4� � E � - --� �� � � � � - ��t i T _.p_. �d R ��. < i,,, _�_ . � � I , , 16 ' ' `^, -' (--=- � � �� �' ��' " � �� � ! � , � � - ��I ; � y� 4' 1� • � i\ , � �:�5', iA ��F,�-f ( ,I I.��'�.rl � � , l-Y i I l �.I�1 �� � f �•.f"� � rY��ij , .} �I If �'� ti, e , 1 ' I �� . Y.-i[��?.� ,�'..:i� .�'�r,,-` j �j K� ` �� . •vy'"`.����II� � `�Clr - - �—� ���' , � "'�A •. �,� �.}�.%.,�:��hf� ' �`��)�. ��� ���i3e%��:�1fl�I 'c�'�� _� I���� � i.. ppp ' t._��. a ♦��., {C•- � .� �yY y���,���n��.,sr1ll �*Z I� �r.r:..y .��..e �.. � e .� �� ?4 �'�{r��c,'��� . � r;`�' �a' ? �. ,"Y t'+ �1C-yr� � ii ��"� � � � � Z'r• ����i� 1 i '` �r rs��.`ii� ��' r� � �*��� ..•a .�I�j�t -�t;_ �.; � �,�a � ` w�� +�i�:��+5.r�' �'�� � t`'`� t �� ��v.a ` ,'� 1 �!,� ��-+nj.� _ .�•� �R I ���r i�: », �. ` '-- —-- - -- � �� `� � (.• �� z �f a �i � ` ;"� �.�� � � � � �� ��� F� � � � Xa'"� ��,� � � � � �,� �� ��� � �, � .���:: �� � ;Y; ��� ,r,L. � r� .�� 't�.,�1,� �� y �'0`r:_:t�� '�� + �i�. �. r I �. ' j��y ,, 7� i ,'�.s � f ��� �� � �, � � . . ,,�- .�JI � -r : i<� •a• "� �i.�_1�L�7� 1, I �� �-.. � - _ : �.�� 1 r� � �,� .'°'�"""'� Ii ,. , , I »� ;.�• �� �' 1 ` � .L..1--�-. �,]�` �� -• 1� -�� 1� r' . ' � � � `�� .t� � �I. ♦� , �� � ��r �. �(t�.' ,�__ , 1yI� '�`/.�� /�% � � '���.4�•�f t :�q�''' .'�.• . . . I ✓ � 1.�1-` ��w!I�I 4 Y��� '1.'� • �/��f�C�y�� , { I� � '� \/1 �♦ 1 r rF � a �� .1, � ��/,L - -- � � , / 'e ..� ��:�',�:s?i t.�� ��� ����� � I .��,' �'�L � �, .` ' r t. �=7 , ,'., - � ����. � �M '.,. 1-_� �; Y' � .� ,� y����� �a''a� �L�'. �' /�� . ,� (II '�'` �� �i;Gr��° ,� �� 1 ..F+,���" � � k�€� ��� — .-��,� ��J�y'''i� \ ♦ �� `.� `��� � 1 n .�'"�-^s�' I�/ *��'- e.'� � ��,+�r„�� � '�li�' ' �� �k'i .._ q !�A -:`.� } `\ .•� ("'�/ / A/� ''S� r% , �' .xi� ,� '��' �"r �rc. , � /� �i� � s �� � \\ , j Kk.:'vI 4 � � ` � -�� ,� e ( �� ✓ �. a, � �.. ��, t'�� � .� �� � � —�. /" �+ f �h :; .y�.' ,'� �� � i�� `":.'f / ����P��� � �r�A t4 �.�, �,$ •�_ ___ . r�V �.'rir:: �'�` J ,�tl;' ': i ��-0S'�ia 4x� ,J'a . I �� d -K `�4 '�� � • • 'o � 'p (,� L_ ; �' ..,y , � �� ',�1`y,:..•,� I�� �.�C��' I ~ . `� � •t ''�'J.1' R h. ���.. �� 1�1+�:'-���� �.al V! � I � \ �l �� i„'1R �.:(.: N.(Y �_t�PI� --� �.�..ffJ��' ��'� �. � '�• �,t�, \ w' , ,� D .�:� .�p� �l I�Iti'L `j.,� ��'� M�j'��'t'fH'��L_�\�/`� �F� �N, .A:R i ,�t��\� ���'?�� ,� \lr }\'�:a . °, r �� _s¢��. � 1�• %� � r�% — f�1 �.' t �� � ...----��,.- - 4r��►� �� \r� `��,:�: .��a� .� .� �i �-.1`. �a�i�� �� ' ��� �. :� ,'�':; I ��.� . { !�- -- -� �,:r 'r�_�,�t.,* -,���. � . ��.`i�j;; _:;. . �- .. , . ,;. .t�� � � a. �r� , �/��r'�.� 6'• � �'�" �h''� raF'�`yi' —�y,-r�,r,� ,r: �.� ., � � . ' " .I/���I i:.� jS��-R' •.�I'����LSM�. r�,��ft .ti.� � "Fl .� �� _ ! �,� ] r � r '-�- ',�'� r j`' =t .T '�3'' `"" � f` � . ` I ��},�1.f�'�1� R } \���� ♦ � '' � . �� ��•� . .S ���IL�� -- �.�t r�� -,�;Y;�r'r x.t_ +'���;f.J �• �'� .- ��'�i�l�A�!!�i! � �'�\i ���,`-;"t'°�r'�' �'"�,s. �,!" , '��,� I�. `-� I '�� �" _ ��,�4�`iR�'� i _ �'1�,j _ � ' . "� . .,� �n�ru asrs��r . +���- ''i-�'C•,�F��'`����r" •/ � - , I ,� .,'r� . .` ��L'y" ''�h�l � � •:� :: �.�,.�gIj�.•r:������ �• T�- ��,,��yy/ I �o-- . �. �`�'.STl�'� ' ' `��,' z 1'� n i k�� . . . � ��AA. �0�:`.'rdht,.��`/� :i �j. '/ '.'�t�n � K ���tllC ,�e'�.�'f�. !� -�� � s \ �l t�." �' '��� .� 'I ~e'� '� � �«�. .��.�i�..� .-'5... '�\�� q �f -' "' _ �\ ' --� .>7�•LrY _ ` ---- -� ;i. . �.. • t ,� �►;3'��. K,v_� I-- 1' ti�:�M�II ' � I � , . . � -- . 5' --- � '� ` I{ "-'�� I . � _""�"•�f)\ � [�a � `�--� � 2 �� � 1 -- — :�n-r. . . . I �Ral L•`ll—_ ��•��—i�I- _ ' �;'l �,w. �r� �4�' � . . � � � "• � (�` �' �'"� t- �� ,�-,�� - - , . ��� �� 1 -- � � \' k= � �� � �'�., ` .�. . - ;,. , :,- 1 .� ---- � ;: �� , "t� ( , �• � r i_�'�e '�. ,' ':�.L�'�,, .r' .� � Sl�._ �� _ _ ,��, ,, ��. ,i� � . . � �-'Y�� � � ,t •�� ' �'�-�y ' I I �C: � s � �•.f�;� ���" \ . . �,. .�R.:� . � — ��] � .'t�� .� � � e` �I/.�J�I � y . -. .;�.b� 1 ' - i�[t='i7l 1 � •� �1I���,� • � 11 .. �I � I�rl ��.f�l ��i .�1._ �� � ' '' '� ` � =�1� ,: __ - _ t_..� _ ,�_ , , �,,. �� , �. :� 3,.�� \ ;� � , ,��._,,,�; .q--.� �� ��� � � yj�' 1 i:� � r` \\ '� 1� ��� "~ �'���.��� � - � ,�.,. ..� � � � ���;���+++i�i�dl�,av��-e���``�I[�tl�}�,�. � i+ '� - -- I �'Ss:i::i:jc:;';:::>:i: /',�/�� a�I��. �.r��r+�1, . .. , . - . , � 11. CORE AND SPECIAL REQUIRENIENTS CORE REQLJIRF_.MENT #1: DISCHARGE AT NATURAf, I,OCA"TION The allowable outflow firom the site will be discharged to its natural location. �I'he lowest elevation for the basin is approximately 350'. CORE REQUIREI�4ENTS #2: OFF-SITE ANALYSIS Refer to off-site analysis on subsequent pages. CORE REQUIREMENTS #3: RUNOFF CONTROL Calculations are provided on subsequent pages addressing peak runof��. Sizin� t��r peak rate runc�tl� control facility to le��el ? fl���v control requiretnents. Water c�uality c��ntr��l ��vill he ��rc���icled in <� form of a wet-vatilt CORE REQUIREMENTS #4: CONVEYANCE SYST'E�1 The conveyance system wil( be designed using the rational methoci CORE REQUIREMENTS #5: EROSION/SEDIMENTA"1 1O�� c �),� I IZ�)L_ I'L.'� The Erosion/Sedirnentation control facilities will consist of filter fabric fences to be plac��,� .�,� the nortli and northeast boundary of the site. CORE REQUIREMENT #6. - Maintenance and operatic��� Maintenance involves having on-site catch basins � I����������, ��� ��°�� ����i�� �� ,��:� � ����°� ��� GORE REQU[REMENT #7. - Bonds and liability SPECIAL REQUIREMENTS: THOSE APPLICABLE TO PROJEC'1' I . Critical Urainage Area - The drainage basin is not part of any critical ciraina��e area 2. Compliance with existing Master Drainage Plan — N/A � ('c�nditic�n� Requirin�� �1aster Drainage Plan Ni,�� �. Adopted C3asin or Community Platas - '�I/A, f lo��-ever. tlie site is dr�iiis lr� I.ake Washington via Sunset boulevard 5. Special V��ater Quality Controls - The proposal will create U.�7 acres of new asphalt l lie special «ater y�ialit�� controls tivill be in the form of��et-vaults. See section l�' c�f tl�i5 report. I'�. - �} �1 iP rain- s�i.r._� y I 8. Use of�I.,akes, Wetlands, or vepressions tor Uetenti�n - N/.<1 9. Delineation of 100-vear Flood Plain — N/A 10. Flood Protection for Type 1 and 2 Steam— N/A I 1. Geotechnical Analysis and Report — Geotechnical study is being prepar-ed in conjunction with this application. 12. Soil Analysis and Report — Geotechnical report has been prepared f��r this site and addresses the soil classifications and stability. 13. A Wetland ivlitigation Report —NIA. Pg. - 5 P�l� r�._,. _ _..-3- 111. OFF-SITF, ANALYSIS UPSTREAM The I.78 acre site is situated with 0.65 acres adjacent and upstream to total a 2.43 acre drainage basin. The 0.65 acre basin area upstream of the site consists of three residential lots. The basin surface run-off will be accounted for in the storm water detention facility for Elle Rain Place. DOWNSTREAM Surf'ace runoff from the site is directed to the northeast. The detained and treated site outflow would be directed to a 12" conveyance pipe leading southeasterly to a high density polyethylene pipe installed with the Rose Short Plat lying directly to the east. The runoff will be tightlined to the bottom of the steep slope leading to Honey Creek. A l2 polyethylene sewer pipe was installed along the west margin of Honey creek about 1986 per sewer drawing s-1432. This sewer pipe appears to have been installed to have about 5' to 6' of cover. The creek is about 4 to 5' wide with cobbles and gravel bottom. The stream meanders with heavy brush and tree overhangs for about 1800 feet to NE 27`� St. to the northwest. At about 300' upstream from NE 27`� St. as shown on Thomas Brothers sheet 626, Honey Creek makes a bend to the northeast to cross under a 12' wide, 15' long bridge with concrete abutments. About 200 feet downstream of the bridge the creek enters a 54" 100' long culvert that appears to have a riprap spillway constructed above the pipe as an overflow if the 54' pipe is full. A 60" diameter culvert 40' long carries Honey creek under NE 27�' St. and continues northwesterly toward May Creek about 1200' downstream. Honey Creek is a tributary of May Creek which lies about 3600' north northwest of the proposed Elle Rain project site. May Creek main stream has been inventoried as a salmonid habitat for Chinook, coho and sockeye salmon. The City of Renton inventoried May Creek as part of their "Critical Areas Inventory, City of Renton Wetlands and Stream Corridors", June 1991. There does not appear to be overflow or flooding problems within ';1 mile do�tinstream of the proposed site. Pg. — 6 ELLE-RAIN-SD.DOC � si� 59G �, r,nr . ' • - - --- — .�"�A. E -1 F--- ------ �---- , � ..,,,;----- �-- --- - - � H-- - ` � Q _ �n ___ �.. .� �� .�. . ,� . . _�t-11�111�Sf"'�"'� � ��--w '% i ti �, \ SE6/ M i �a -.� a�, :rr � ._ ,m �' ,� �; �F,� �, Cp v#�, ^-' o-n, r � $E'• `t �BIH ?i �' Sr�r� '1'� srreM �m .:�,a� { q s ,:�;! 7`���,�y��^�;�.,,Sf� �yy, „SI �' ��m�n � Fs "69TH_' ,� �� '��;�� i l.'._r.y.,�`� ��°"' `�?� � $ �� R'� `ri� I' % �' st�� iuin w 5[ �N�# �.�_ _ n ? -� ,� • (���'�',h����";�j;:' � {� ( tl /n111'I51 I� - Ct N IOIICLd - � (��i . �;: � ?m 'ii 12 �f� v� � ' `�'E' 1iSt �Q �, tt SF 79ND,^�y . I ��' v�n flSI SI�� (C � '? .t �•• �O-�:I . � ��.. � �—� � , ,( ' J; (11� '�! �ll lo �� ^ r 11 ISI �ISI 1'1�n � � -'�! /]MI ST r�j l� ,7 .�,I.�; 1 7 � �. n� .i� �` � .Sf-�v ° L SF� TJM7 �S! ��vD -�i 771) PL .T �\ �/ � �LF,.i'. , n . . r� 4MF 50/M II:IZfII�'1700� � 11. 1) '�a- j"�5 c� `o i iu I ^ 1 �� - rr p�;`; �.. u' ;i�,� � 1'ARK�'d��'� r � � '��l,��l ���i � "' � �:" %D ClU6 � W;yy' n:. 'S `19 :��� n,.7r �> �`� � \�f �p ' '�f ^ cn i'' �^ ",�� - � � t. , � � �! �� filfl_.r 1, SI _,.S' '�.-� r"�;E s A�� ��` �7ti .N-__Sf��')� � '` ,t r,����� - Ar.1�F �'���� ,,. I � " �iFu�Iri 'F� �ii� `� �ie ���<•� � � �-i>n•� _.. -S . � . � . : ` ' 1�?tf �.�•1 I `� jF�i�r�`� I^' \ '_ 51. �,1� i�:� �✓:iMfl�i�$/l.E I G '^Ip�`a. � r'I 1: ! /.; _ ,, �1 �E ISfP 1'L 7fi111�P1 � � � � Z � � .r r1ni . i vi S( ,�ni�i.� �� '°'ii 5�� `{� I, .ht . i �� � � � n . � A�. ; S .�lis � 'r��.F� �, : �S� att t� � . N � , � , �y �>� � r � r� � I � � :1 .. .I � � � . �. K +kru\ r.,I 1 �1 y}� ,r t n:� .`I �`� ,.r„ \/ ,, 1 �?v ,S, ��l p .c ,te, r � �,�.h�'i�'•{��,�.r I SI lallllr�ni si � SI f.. i :/n` ti \�i`�.. �C�f' "'" , 1 �' �r � .�..E.1 c, . � � II."nn �I1fir10 m _� : ,� A�St SES . •� • 9 11 4.. a+� � ._ � �. I ,� `� etsi - .A✓y t:'� Y�� :i � I141R �y�_. � �. `ISE 1RIN.SrH�•;„ Z� �. �� I ,. ' r ..�. ti OL 'eiin . .� " � aj�r��n 79111_�i, I)R 'Fno y(� I' ��.. nzM� �n �1Qf 4 � � �,.�� �!• f t��m� c � r 0*� � c 'v. `,,,,,�. c i i « (_ 4'! � i cn � :f 9JNn� � ;� J.r ' ..��: 't .1� lpt,T 4i. +i,.�na�N: -� "ri ^ - - . � ' �'n,Q� °r.� '� f.• � � ��. � � .. _�•-� An�a �' �I�, � sE&1f�� • _ ,,,�.r ��� , ,, p�51 � ,�'� I � -i � esn� � , 1 \ . _ C1 . ��_.. .._... __.j. "� Sf � „y�sCSo__ _ l.A `,I 4 9� I �� � , �:�, � _� ,-. ' �� ,r n5ui�n y ''APTM_ � =�ti J �''� . � �� srX� '� � � ;C BRill tt .l�. tN�i � �' �:�/� /i �� � r L/� 1 � ' SF Mill SF P7111 �liiu ���,�J` �p�jry D �' '� ' '� �� I� t �y�'}' r �' I � - Si `� �� Si$E T!I^'����Pf�r��Sf �,�4�CJa� � T L_� ' V 4`� L_V�. ,".� �/� �EGt ,� hr �� i i rtm :�i ���.,B F Q�' � " ✓� �� ��R�S. ST 'In�,q.R9JNY,�...v�. .9 q1�.-`V Ir�l(ft��. 3 ��, 1,,H�.� 89111 . 8� 5�,, , �.�� �n �;.: I. ` i � f P( P�_ 90IH Si � r, F,_....' z Ea�9/ '.., n � , I NE i sF 91SI�_ Sl. Pr � `F'`�\,n �R I � -.�- ...-� 92M1 SI�W'"I ��:x17I(Ml 'J, tC 9���^` CF � � i � E � (��I �'�. � • 9ISI SI �' � _____—� �N `� ��� � �, _ _ sa� w w_ � 31S Sr I �tr I ^i� ' __� '�i � ��. ���' y�w N ! -„ p� � r 2: � a S( i�,,t' l,� ,,�t��'� • � „ ��+,t.�Y_-- S£ '�"t,, U �Y �. � l `s� r . � ����- � � 95t� �zi�i� � �S �k� Y � T �N���EY �� ,� �r � _RU � � 8TH r ST ♦, .��t�k[ � }�� d, '� _9LSEy,t��r�—-.- . m _ _ � -.. . - - - _ �1� ��', � 'Cl MM� � �1 AV �r1 J �.]• h"` .s � �.�,�s,�:'�A z ,,. �4 . /1/ .`P Y i 27pq `� ar_�s`' fERRA _��-��" �` � ��' ,�,,,�, � �S f�S � � sr �n� l� �'a , �. (/ ' ,., 3 •,.� .. r ����.K'' ��.- a�^• 1�fH =7 f i N�G 25iH �PL "��1 � I. ��i ,.'.�, �1 � ~ _. ,,, �,StH n � , l, '! .i �. 5 �.�'�E o ttnl cr" � � � <c InniN SE�OQTM I s . '^ � � � G _ rooiH �u ' � _tE ��.ir,n�ii � _ s9 � > ' � �--- � x iwir PL v7 ' ��m r - .. i � � ^ Y � .�,.� �R� �.-,,11 �_ _ � J < `I S ��-.� ..�� � f��� iE _"L 102N0 �< NE hE�OD fT _ —.�-.` 29np k SE Inn�n s�i � — 2�m• , !C� s�A ty l' .� � E '�'�}iU 3 Mt � +y a` � I ,.� j t � S i a ST N �87'k � '� � � ' 3 N � 21$T ' Q ` � u� Irn �p tr I y $ w Q ��C Y.�r r�.=�. ll[tt �-P�, },4� �i m �.. {��9p�,�a j.�;�. � t� � �� 1[ 20 � � �� �z ��o Y� � I in I - S2�R� � .,. i . �` «� y SE�IOS7N ��- i. �.,. � "�` �.? � �L�E '< �,�,'� �� E G ST � `� sfi .i M'i . N E ' 2 0 T M .S T �E ''� �2 0 t x 5 �J W I _ � � �NE � �; +w ' s p.' �<k`'x,�+]�.. +Y,9TI1 Si � �i� �,aq. � � ) 't �em� v 5 wII� I � "E �.'! � � A � �� � ,� ,f � << in5m ri j �� �[..�n� �T+ Q C� � tt!� <(� � � � nt ` Z r 0 .•LJ . � . `x �ifr�� � �V � 41/>,zt icr��� ME 1 rl � I ; �_n = r �.' � I�1M ll.� --- _ .�ar - �-r• � ' NE T. ,�`���,����� ��" ;i �nin� ri ;�vi 1 y� y� y�. ' �2 �� �t :�. ii' A IS I � /. �— ' . .. �:S . - W ,�r ssoo: '�y .> �$ r�t � ``1� � ,� �� � '�� < NE ` �= 141N � ,':��11�I....:-. . ��..� � � ' � V`'V � �" r ' 1�TH � a� ; � . � RISM h y w _ �_ m�E 3tH=i n �o � � � �� 4 P;} ��c uTM sr �' u�asr�,� � � �c, I ` •t'F 1 t,,, ��� � - 8 �' t�nr sT le y ' � �4 ; "� �."> - � �CRE k � PFy..� -, �pS�P,. � � t2TH_ Si NE � � �' �2TH r '; � $T� �, SE "' g �N �`'' `�O� � zioo ]�� ; 9,�, r :�, , e ,y�a�oo .� sr , l lzr�c ;, I . 6 ' S �� m�q. r,.�� {d' � -. Sla a , id��in � I �� K �I<p � ro � 3 �tY t ��., G ' �'=; yauv H r � . R R' ..�� � � �,� , ,�, :r , , �wt h } 1�: i �a� J� - w,� �.tl A M 1K � I 'W 4 �1 �r� i �� �; ; � , ,� � `h� :r �e �.�I i r ,,, �=�� !r NE ton� r ' z � ' �' '��s", n� " � � � � imni vt`r i � sd. r. I'� nE totx Si' � s � , � i .�,�" : �tt` ����s�� _ornr �<� s �., NE t� ::S M� t NE 9TN PL sTM � < � �c � , � ��i NF r ���m�.� �i�� Q � 25 '" � �E'��-: . •-�i ��9fH r9 � Sf >w �' E '91H �r r •HE 9 cz � c ..> -4, �c� _ ' SE llRiry a S���NE 9nl;r NE 8 , L f�MF, Q,.� �]� �4�, � �. ,t '�.' . . s 2'" ��" � 1 ,J. ^� .� � .J g � '.��> KE91 . 2 ,❑ „J� c 1�� li� ,� � � �M I� O� � Nf; = II � NE !8 h� I.� NE 7tN � � E 81H $T "' . �j ~ i ' � 6� � NE �j ��gw, NE�iH.".$�����,Sirt�� SZ : '� ME m7THPl tf I71Si >i ��• !'�� � ' S , � � IN � .,pr .�- .�,� '?`� 7iH ST � .�rr1'•.,� �.�� �-+ T' SEJ 127NU � `I n� Q (a 6 7 p� NE � :,�� K � s`. �IIPt � Si � �S "}�-'-' � ..� ME -� - . __ � -.a. �L...._. k i.�.�__ 'W . /\ _ \ . . . �- `.. __ . .. _ ` _ �_ _ j �. �l a�\ _656 /Hnr I., .. � f \ ` a�.�\ ' '��\� � '� ` �. f„3 a� f �` � '� U „�'�� 4 � + � f �X. 1 �� �� rx y,.�t'�� � ,i; ,, ` : � �{' `I '.z, t� � a"�i �.� t• �,,. .9y � t}. �� �� ; � t Pj ay t. ,t'� �l-ri 1Y x Vt�gs `i i �'2 /� 1:fu � , JL,.'a �a�. (�� �'+;��1 . \'� � .��. T r v b � "'�_ �''t�•;,�'�r�'�'. _. � �.` 'ji�� 6 {� ;'r . :� ;` � ;11��. � ,�� � � ,,y t r. � 1 ` � J'.�'. 9r•. � , t:... � � :� -,Ss _ �� 1 � ,� � , ,•. �, ��. :,'� � �. . I r TR � '� z. j ; {�, t,. `�` ``} �� ( � �1 1� �``� .� 11`� , tR +r'� • {� 1 � ��5� ��: � �-r� , 'p� .. , . y ..r�. �I ;•� j�':� �l���`,�y. L:a �\ * "}�� �� { . • .��riy ��. �v ' . \ s :t �' �' 1�� ��+ �,i" M y�. t �� .,� .,�}��, .. �. f1� ` \ = 4 y� :�-Y3,�� }�, i. '�'St�L`�il+` \\ � ti.`! �}'f �t'� �,S ,�.�y`},�i���, -�'. . � �. i �: n.. i�•s�F, t� � , ` , ; J ' +,,� C` ��� ;�. ��. 397 X � �C � � - � \ �'r 4 }S 1 �. .�' , , k, t �� � w,� �1 .. � �` , -k 40 �\\ � � \ \ '�` i / `� � � //,y,�/� ` \ \ ��... / � ,c--� Q � �. /°i� k- �\X �� � � � ���� �` '• .h'O �t';���,a� ,. .�r :t Yti�\ �.�.-�p� x F�;i` � j�, , 2 ti� ,��;: TREES. � � _ .,�, F :�i � ��L �',� / , � �� .� k� ; .,� ��,e�-� ���1 ,` ;. � � � TREES � �` `'"•i: r id a� ,r`�r�_ �:- �. O -. , r . ti \' r ] r'M' �. 6 . � m - [ '�' { > '�;. J t, '= �� �':`ti� Q f '�� � � .1 ''`�:' '' F— � � '�` '��.� � 9. . ' I j',� �a��Yk�'A��k, �.}.. �� . ,L � ��� t �1 ' �F�S''�`�fIr � � � �� .�- •:. a •�'u �� . "^"�)' ���: I _�,�=�� . `.�� �Eru. �.9.« � y � ,i a. i.� \ � . ��a #' . _.+.�•,. .�� , .�.1 .,Y4�; :` ► i , � .{_. , . �, �, � Y :°+.° ��. ��"°� �. `�; f� "�� _. 1 � .�--- ��`�, � � =� � �-�,= �; ; �' I I x :�i�. f � .�.-���-�.�E� ,� `��:. , ;� _ � � 1 I � q 3 �«� �, '�, . — 6 ; ,� s� �-,��" fi -;.� 1!�T X . _. � `_ ( , a ,, '� a.: �.4� °J ``�. . , r � �sr> s �, i � /I/� - `. . ^ , � Z� � � � �� a � 1 /�ii� ;," . , (� ��'. � � . ��� � �'S79X I T � J J , � ; I` � � �J � \ 1 \ "� ���^�1 + , w w `--- `--X � DR� _, I C R E�K ��O � I \ w W 400 �� I �� , m m I � � � �^ ] \,. � �- -�'� , _ - , 1 = 200 , _ x� ' ; � P � I _� I � �' �, � � f�l I �--- , , , iz�t{ ry N , � ��, r� , TRFFc . . m. }i.� J f-1 �� i i l e I I '-1 ir . i' i:t)11 � �.� Ai �cili, �..1i) ��:\ � it•.iii)i °� � i91 '('he Preliminary Report to th�e Hearing Examin��r� ►t�r h��arir�p� 1����il :_'.��_ _'������ � �,���i,�., tl���i ii���, proposal should be designed in accordance witt� the 1998 KCSWDM Level 2 Flow contrc�l Match the discharge durations for the ��nc,,, „+��,.t,�{:,� ,,I,,,,,,;a ��;�,•�,•„<,,, ,.,�,,_ ��,.,,,, ;n� �,r;i . _year peak to the full 50-year peak flc> The area of the plat to be developed is 1.7b a�re�s, incJudin� asphalt pa�,�i���. dri��e����ays, huuse� and landscaping. About 0.65 acres along NE 17`t' street, houses and lats 1,2,3,and 4 of the Hor<<�� Creek Yark plat are adjacent and drain across the proposed 1 I lots (10 adciitional). 'I'he draina��� basin and new added houses, asphalt paving and drivewa_ys will be directed tt�rougll a detention/wet-vault for Water Qualit_y measures. The roof runofffrom thc nel� h�><<se, �1ill f�e collected in catch basin pick-�ips and directec� t� the conveyance s��steni_ Pre-De��eloped Couditions Pervious Forest 1.71 acres Urass 0.•o acres Impervious 4 Roof and Driveways 0.27 acres Existing Half Street 0.09 acres 0 �6 acres Post-Ueveloped Pervious Lawn & Landscaping (36590SF) 0.84 acres [mpervious New Street & sidewalks l.,ots (use 4000SF or 75% oflot whichever is less Section 3.2.2. I KCSWDM) Lot/area SQ. FT. 75% Imp Area Imp Area Used I_ot 1 4700 SF. 3525 SF 3525 SF L��t ? �639 SF 3479 SF �479 SF Lot 3 6141 SF 4607 SF 4000 SF I,ot 4 4704 SF 3530 SF 3530 SF l.c�t 5 4551 SF 3413 SF 3413 SF Lot 6 4543 SF 3407 SF 3407 SF Lot 7 6070 SF 4554 SF 4000 SF Lot 8 4519 SF 3389 SF 3389 SF L,ot 9 4954 SF 3715 SF 3715 SF Lot 10 8959 SF 6719 SF 4000 SF Lot 1 1 5147 SF 3860 SF 3860 SF Total Lot lmpervious 40,31 S SF� = 0.�)� r�C. Pg. - 9 e11e-rai.n-�d.dcc New road and sidewalks 0.37 AC. Fx. � lots 0.20 AC. Ex ''; rc►ad U.09 AC. �I�otal 0.66 AC. (28,942 SF) The above information will be used in the King County KCR'TS computer program to establish the existing and proposed time series for the peak flow and duration anal��sis. "!'he calculated vault ���ill be 70' x �7' x 8' deep inside measure. There will be a wetpool for water quality within the sarne vauit. ��'ATER Qli:�l,l'I'l �I�he wet-vault permanent pc�c�l �vill be sized per section 6.4. 1 . l, page (�-7O c�f the KCSWDM The V� _ (0.9A; + 0.25A,e + 0.l OAIf+O.OI Ao) x (R/12) V�= volume of runoff from mean annual storm A; = area of impervious SF Atg= area of till grass soil covered with grass SF A�f= area of till forest soil covered with forest SF A„ = area of outwash soil covered with grass or forest SF � R = rainfall from mean annual storm(figure 6.4.1.A) = 0.4T' �', _ (0.9(69,260) + 0.25(36,590) ) x (0.47/12) _ (62,334 + 9,148) 0.47/12 = (71,482)(0.47/12) = 2,800 CF �'b = 3(2,800) = 8,399 CF Depth — 8399/(70x37) — 3.25' E310-FILTRATION We have accommodated the water quality for the bio-filtration action �vithin the �vetpond as designed above. Pg. - 10 elle-rain-sd.doc KCRTS Command � ------------- I �'REATE a new Time Series ��I ------------------------ � nr.oduction of Runoff Time Series �, Project Locati-on : Sea-Tac i �omputing Series : PREDEV.tsf I Reqional Scale Factor : 1 .00 Data Type : Reduced Creating Hourly Time Series File Loading Time Series File:C:\KC_SWDM\KC_DATA\STTF60R.rnf . Till Forest 1 .71 acres Loading Time Series File:C:\KC_SWDM\KC_DATA\STTG60R.rnf . Till Grass 0.36 acres Loading Time Series File:C:\KC_SWDM\KC_DATA\STEI60R.rnf . Impervio�as 0.36 acres -------------- Total Area : 2 .43 acres Peak DS_sc.harqe: 0. 36Q �"F;� at 6:00 on Jan 9 in Year 8 Storing Time Series File:PREDEV.tsf . Time Series Computed KCRTS Command �'R.EP.`I'E a new Time Series ------------------------ Production of Runoff Time Series Project Location : Sea-Tac Computing Series : DEV.tsf Regional Scale Factor : 1.00 Data Type : Reduced Creating Hourly Time Series File Loading Time Series File:C:\KC_SWDM\KC_DATA\STTG60R.rnf . Till Grass 0.84 acres Loading Time Series File:C:\KC_SWDM\KC_DATA\STEI60R.rnf . Impervious 1.59 acres -------------- Total Area : 2.43 acres Peak Uischarcte: 0.929 CFS at 6:00 on Jan 9 in Year 8 Storing Time Series File:DEV.tsf . Time Series Computed KCRTS Command e?:it KCRTS Program ------------------ � _' I I �"'� • . F1ow F'r_equency Analysis Time Series File:predev.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS} Period 0.200 4 2/09/O1 15:00 0.368 1 100.00 0.99C! 0.121 7 1/05/02 16:00 0.214 2 25.00 0.960 0.214 2 2/27/03 7:00 0.202 3 10.00 0.900 0.096 8 8/26/04 2:00 0.200 4 5.00 0.800 0. 121 6 1/05/05 B:00 0.183 5 3.00 0. 66? 0.202 3 1/18/06 16:00 0.121 6 2.00 0.500 0. 183 5 11/24/06 3:00 0.121 7 1 .30 0.231 0.368 1 1/09/0£3 6:00 0.096 8 1 . ].0 0.�91 Computed Peaks 0.317 Sn.On r.�, 9s�n Flow Frequency Analysis Time Series File:dev.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis---- Flow Rate Rank Time of Peak - - Peaks - - Rank Return Pr (CFS) (CFS) Period 0.460 6 2/09/O1 2:00 0.929 1 100.00 0. 0.378 8 1/05/02 16:00 0.599 2 25.00 O.u� I 0.553 3 2/27/03 7:00 0.553 3 10.00 0.9n! 0.412 7 8/26/04 2:00 0.495 4 5.00 0.60' 0.995 4 10/28/04 16:00 0.489 5 3.00 0.667 0.489 5 1/18/06 16:U0 0.460 6 2.00 O.SOCi 0.599 2 10/26/06 0;00 0.412 7 1.30 0.23'_ 0.929 1 1/09/08 6:00 0.378 8 1. 10 0.091 Computed Peaks 0.819 50.00 0.980 � r� rz �- r� v� � 'L o�.T� � � cc��+�� �� oc_ ��r�� )1 � 1 �12V14 �-- �D% Z� r. O , !Zl /� - ,� ,�� � � ��i � f: r% �i 61 l. � (Z- �� ; S 0 '�' ,�- _ ��L o f� Z y� � �l.r 7 .n Fl � � �, � 1�7 - . vL> .. - � 7_71 ;' �3L -' � - i . - • U''>? �pf � ��� Retention/Uetentiori Facility STREAMI.DOC �-- � , `` li��>�� Type of Facility: Detention Vault � � � ' Facility Length: 70.00 ft Facility Width: 37.00 ft Facility Area: 2590. sq. ft Effective Storage Depth: 8.00 ft � �p �� j='1 �' ►� Stage 0 Elevation: 350.20 ft ' ��w��� F D Z ,, ! _ r Storage Volume: 20720. cu. ft ���T �l� �- � i ? E"r"��F �� ��/" Riser Head: 8.00 ft Riser Diameter: 12.00 inches Number of orifices: 3 Full Head Pipe Orifice # Height Diameter Discharge Diameter (ft) (in) (CFS) (in) 1 0.00 1.05 0.085 2 4.65 1.35 0.090 4.0 - ,3 5`�� �'S 3 7.20 1.20 0. 035 4.0 ..�, :;�, �' p Top Notch Weir: None Outflow Rating Curve: None Stage Elevation Storage Discharge Percolation (f.t) (ft) (cu. ft) (ac-ft) (cfs) (cfs) 0.00 350.20 0. 0.000 0.000 0.00 0.01 350.21 26. 0.001 0.003 �.00 0. 02 350.22 52. 0. 001 0.004 0. 00 0. 03 350.23 78. 0. 002 0.005 0.00 0. 04 350.24 104. 0.002 0.006 0.00 0. 05 350.25 130. 0.003 0.007 0.00 � 0. 07 350.27 181. 0.004 0.008 0.00 0.08 350.28 207. 0.005 0.008 0.00 n. 09 350.29 233. 0.005 0.009 0.00 0. 10 350.30 259. 0.006 0.009 0.00 0.26 350.46 673. 0.015 0.015 0. 00 0. 41 350.61 1062. 0.029 0.019 0.00 n. 57 350.77 1476. 0.034 0.023 0.00 0.73 350.93 1891. 0.043 0.025 0.00 0. 88 351.08 2279. 0.052 0.028 0.00 1. 04 351.24 2694. 0.062 0.030 0.00 1.20 351.40 3108. 0.071 0.033 0.00 1.35 351.55 3497. 0.080 0.035 0.00 1. 51 351.71 3911. 0.090 0.037 0.00 1. 67 351.87 4325. 0.099 0. 039 0.00 1. 82 352.02 4714. 0.108 0.040 0.00 1. 98 352. 18 5128. 0.118 0. 042 0.00 2 . 14 352.34 5593. 0.127 0.044 0. 00 2.29 352.49 5931. 0.136 0.045 0. 00 2. 45 352.65 6346. 0.146 0.047 0.00 2.61 352.81 6760. 0.155 0.048 0.00 2.77 352.97 7174. 0.165 0.050 0.00 2.92 353.12 7563. 0. 174 0. 051 0.00 3.08 353.26 7977. 0.183 0. 052 0.00 3.24 353.44 8392. 0.193 0.054 0.00 3. 39 353.59 8780. 0.202 0.055 0.00 3.55 353.75 9195. 0.211 0.056 0.00 3.71 353.91 9609. 0.221 0.058 0. 00 3. 86 354.06 9997. 0.230 0.059 �J. 00 4. 02 354.22 10412. 0.239 0.060 0.00 4 . 18 354 .38 10826. 0.249 0.061 0.00 �� -- � 3 4.33 354 .53 11215. 0.257 0.062 0.00 4 .49 354.69 11629. 0.267 0.063 0.00 9 .65 359.85 12044. 0.276 0. 064 0.00 4.66 354 .86 12069. 0.277 0.065 0.00 4 .68 354 . 88 12121. 0.278 0.066 0.00 4.69 354.89 12147. 0.279 0.068 0.00 4.71 354.91 12199. 0.280 0.071 0. 00 4 .72 354. 92 12225. 0.281 0.074 0. 00 4.73 354.93 12251. 0.281 0. 079 0.00 4.75 354.95 12303. 0.282 0. 081 0.00 4.76 354.96 12328. 0.283 0.082 0.00 4.78 354 . 98 12380. 0.284 0.083 0.00 4.93 355.13 12769. 0.293 0.093 0.00 5.09 355.29 13183. 0. 303 0. 100 0. 00 5.25 355.45 13598. 0.312 0. 107 �.00 5.40 355. 60 13986. 0.321 0. 112 0. 00 5.56 355.76 14400. 0.331 0.118 0.00 5.72 355.92 14815. 0.340 0.123 0.00 5. 87 356.07 15203. 0.349 0. 127 0.00 6.03 356.23 15618. 0.359 0. 132 0.00 6. 19 356.39 16032. 0.368 0.136 0. 00 6.35 356.55 16447. 0. 378 0.140 0.00 6.50 356.70 16835. 0.386 0. 144 0. 00 6.66 356.86 17249. 0.396 0.147 0.00 6.82 357.02 17664. 0.406 0.151 0.00 6. 97 357.17 16052. 0.414 0.154 0. 00 7 . 13 357.33 18467. 0.424 0.158 0. 00 7.20 357.40 18648. 0.428 0. 159 0.00 "7.21 357.41 18674. 0.429 0.160 0.00 7.22 357.42 18700. 0.429 0.161 0.00 7.24 357.44 18752. 0.430 0. 163 0. 00 7.25 357.45 18778. 0.431 0.165 0.00 7.26 357.46 18@03. 0.432 0.168 0.00 7 .27 357.47 16829. 0.432 0.171 0. 00 7.29 357.49 18881. 0.433 0. 173 0.00 7.30 357.50 18907. 0.434 0. 174 0.00 7.31 357.51 16933. 0.435 0. 175 0.00 7.47 357.67 19347. 0.444 0.185 0. 00 7.63 357.83 19762. 0.454 0. 193 0.00 7.78 357.98 20150. 0.463 0.201 0.00 7. 94 358.19 20565. 0.472 0.208 0.00 8.00 358.20 20720. 0.476 0.210 0. 00 8. 10 358.30 20979. 0.482 0. 522 0.00 8.20 358.40 21238. 0.488 1.090 0.00 8.30 358.50 21997. 0.494 1.820 0.00 8.40 358.60 21756. 0.499 2.620 0.00 8.50 358.70 22015. 0.505 2. 900 0.00 8.60 358.80 22274. 0.511 3.160 0.00 8.70 358.90 22533. 0.517 3.400 0.00 8.80 359.00 22792. 0.523 3.620 0.00 8.90 359. 10 23051. 0.529 3. 830 0.00 9. 00 359.20 23310. 0.535 4.030 0.00 9. 10 359.30 23569. 0.541 4.210 0.00 9.20 359.40 23828. 0.547 4.390 0.00 9.30 359.50 24067. 0.553 4 .570 0.00 9. 40 359.60 24346. 0.559 4.730 0. 00 9.50 359.70 24605. 0.565 4.890 0.00 9.60 359.80 24864. 0.571 5.050 0.00 �� - ' y i � v �� /,J�� iUlSPS �C' Si�r� ,_ �lF.��.= / ,� ► �•��.�E �/ Hyd Inflow ouY_flow Peak Storage C21�E k Target Cal Stage Elev (Cu-Ft) (Ac-Ft) 1 0.93 0.37 �.73 8.14 358.34 21074 . 0.484 2 0.60 **}**** 0. 8 4.81 355.01 12459 . 0.286 3 0.55 ******* 0.13 6.14 356.34 15902. 0.365 4 0.50 *��**** 0.05 2.76 352.96 7143. 0. 164 5 0.49 ******* 0. 14 6.49 356.69 16797. 0.386 6 0.46 ******* 0.20 7. 86 358.06 20366. 0.468 7 0.41 ******* 0.05 2.80 353.00 7259. 0. 167 8 0.38 ******* 0.06 3.50 353.70 9055. 0.208 -------------------------------- Duration Comparison Anaylsis Base File: predev.tsf New File: rdout.tsf Cutoff Units: Discharge in CFS -----Fraction of Time----- ---------Check of Tolerance------- Cutoff Base New $Change Probability Base New �Change 0.062 � 0.61E-02 0.98E-02 -21.3 � 0.61E-02 0.062 0.060 -3.3 N E('►�T�✓� 0. 074 � 0.91E-02 0.28E-02 -30. 9 � 0.41E-02 0.074 0.063 -15.0 0.086 � 0.29E-02 0.24E-02 -17.5 � 0.29E-02 0.086 0.070 -18.6 0.099 � 0. 19E-02 0.21E-02 8.5 � 0.19E-02 0.099 0. 104 5.4 0.111 I 0. 14E-02 0.17E-02 23.0 I 0. 14E-02 0. 111 0. 119 �,2 M D2F 7F�� 0. 123 � O. 10E-02 0. 12E-02 10.9 � O.10E-02 0. 123 0. 126 2.2 � �E � P� 0. 135 I 0.78E-03 0.70E-03 -10.4 I 0. 78E-03 0. 135 0. 133 -1. 6 �L 0. 148 I 0. 57E-03 0.39E-03 -31.4 � 0.57E-03 0. 148 0. 141 -4.7 0. 160 I 0.39E-03 0. 16E-03 -58.3 � 0.39E-03 0.160 0. 149 -6.7 0. 172 � 0.26E-03 0.16E-03 -37.5 � 0.26E-03 0.172 0.155 -9.7 0. 184 � 0.13E-03 0. 13E-03 0.0 I 0.13E-03 0. 184 0. 185 0. 4 0.196 I 0.82E-04 0.65E-04 -20. 0 I 0.82E-04 0. 196 0. 193 -1. 9 0.209 I 0. 16E-04 O.00E+00 -100.0 � 0.16E-04 0.209 0.204 -2.0 I Maximum positive excursion = 0.010 cfs ( 9.5�) --- � CS:; _{ �^Oi" �� O�� occurring at 0.105 cfs on the Base Data:predev.tsf and at 0.115 cfs on the New Data:rdout.tsf ' Maximum negative excursion = 0.019 cfs (-23.3�) ', occurring at 0. 084 cfs on the Base Data:predev.tsf and at 0.064 cfs on the New Data:rdout.tsf � � �S + rdout.dur + TARGET.dur • ♦ I ♦ --___ -- -�— — ♦ ♦ - ♦ _ .__ __ _ ♦ -- ----------— ♦ • ♦ ♦ ♦ ♦ ♦ ♦ - _ --__ __ _ _ _-----------_ - -- — --- ------ ♦ ♦ ♦ ♦ _ _- ------ — -- - - ♦ - _ _ _- _ _ _- --- ' 10 � 10 �3 10 -2 10 -� 10� __ _ Probabili Exceedence Retum Period . • 10° --_ _---- 2 ' __5 , 10 20 50 100 - —__ --- — _ ___� �e PREDEV.pks in Sea-Tac . � • RDOUT.pks � � � �� � M�A-T�H �2 Do raoT �x�rr-,o i ��K F�ows 2 � �, i o �.2� R • ; i R -- - - - � m � O �p��2 v�` � o00 - --- __ ♦ � � � � U I � � v, �o-� ' ��2- ok �- — _ __�- ____ _ ._ ca .. U -i � N � � 1 � �� ---_- -----— � � ♦ in� ♦ � i � �� .� � � � I �.i i -� 10-2 _._ _ ,_ __ _� . —,-- _ _. _ _ _T__— -- _ __ � 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99 Cumulabve Probability I , j , ��.�, �.TL 3 5 . ` � \\ ��� �� '��� ���'� \`�'� ���. -------- ` ,� , __ _ , `. 1 . ,y�, •y,. y ,' , `� `1l �', ,� ,� b a� i � �y\ �` ,�•` ,'. ,�_ -.. . _ \� S8H'.'-� ..� _ � — — ..___-,- R 3t � � ``1 \`\ � � ,�� �T j ~`, .``\ � 'y � t11 \`, �`, `,1_ �` , , � � � � , � � � , , � Z , � � , , � ` � � � ` , � � . . � . . . . , , � � � � . . � � `� ' I `,�I, ``,1 "-- `� �►� '---'-'--'- .. .��,,,o � y ��' -�.� �1 1 �� -. � �` � ; � . . ,:.,• ', 'e, �� - -- -- -- Q[AO�t1�M ��1A- i � I " `,•.\ � .`` ._ '' �, r=_-____� _ �1D7NI1T � . . ' � ' � � � � � � � , � � � � .' � _ . _ , � � . : � ` / '� i I � \ �� ' � � �-- - . . . . � I'. , � , 1 1 ; � ♦� -. �`.� • � -_ }•�,�� - _ "'- I � � �, �... `.,,�`,� _ � .�i. ``\ '� i R C'•. ''- " � ' \ ♦ , � R �\ �,•' e'�'�-,�,? ' 's�- � -- . . , \ . �`. � r . . . . . 'i .-. �\ � . � . ,S , , . `•. 1 . . , 1 � � - ♦•' ' � �•.�- `'��_.� �� � i— .�.J � � ' ,, ., .� . . � ; � � � � � � `. . � � . .. . . . •, � � . � � , ; � � . ?� : _ ��i ,. . 1 . . . . I � , � � � . . � , , � , • � � '�i � ;� I I � ♦' . . ----ti-�--,� ---1--1- w-S-'�� � . � � , ( � � -----'� . ._._ _..._.- : ' �� '� i � -i- �I ...i . � .. ----�-_- `.. ,, . . .. � � �, � , , /, _ � ` '----::�. ; , - --�� 1" 50' ; �• .� ' --, ; ; , -�--------='y- --�=� ���..r,::-��•;� �;� �ALE _ �� �r` A=;�E31, A� ; -- _- -- •'=.- � i �` ,�r' _ ` �`, ---- �� ---- '_ `- ;___ _ ---_ `;�•�;��'''iy,� ,� � ��� �'�- �'$0. _ ------- -- ------ '�.; . .��. '�:r-.\ �� � _. � �\ •�;• --- � -------- _ ' -. ` ``.•, ,� •, i. . �`i•. ��` � `'� �; ,'•�� .,_ __ '�'. `�\J�,\'. `'� ����, ..,,� , � �. ♦ ` --- `J�k•.` � `�� 1`�� �h � `�, •�,` ��• `'� '. - . � �_ — ��_` _' `••` `� ���\ .\� � _ - �$ '•�\`, ,�-.�.``,` ��`•_�,'� _ ; `` \�� \� / ' `,� \�\` `\, ,�._ '�'�``` ��� \\� �, �� �}_. `t �` �� • � 7Nlf�Y� ` ` " •� _ "" `. '', �N Y ,`'Ul `� � _ ' \ � '\ `\�\,, ' _ __ ' ``\,,1`., ',,��i� a S �� . `\c . ♦ ` `� '�j. ��• ,,,` �•��, 1 � � ` -,_ - '_ ""� t� ' , � �___I . 'f !�`'�+[��`�` `' \�� ._ --'•r,L � , i` ,`\ ,\ .�- � \` .1 -ib _ � ; i, i I — ` , � `, ` •����{ y__^ � � � .3 EX LO 0.20 AC � `5'ae�a�a��" �',,,*',"�= � ; i � '�-- � 1/2 ROAQ = 0.09 AC ; ��. S a � i � � ��• ' y� 11 LOTS � = 0.9,� AC • . ., . — ; ' NL�PTR�AD' – 0.37 AC � ' '� � ; ` GRASS += 0.84 AC ; i � ; !OT i �;e� �;� ; ' � � \� \ ' a �i.s /t I _0'•a ; � HONEY CREE�C ?ARK a `. �, -.,�,, Qr c � ;' ' ' � 'OFF S sr�_ • ; � � r ` i ._. , �� HON �" R�EK;^�.ARK , , . � I _ _ a - _ � - - - - - -:- �. ._ � .� _ -_ _ ..: • - , .� f-" . A=2. 43A C. TO T. : - �----------==-------------- ---------�------�----.----•---- :' DEI/ELOPED . ¢---=__ , ....�.�....r � - �� coNo�r�oNs _ �a�____ __--- �,�,--�-- ---- -- .--�.------- - � , •�..� :TL 35 . . � ,�,, -•- � � . � `����' �� ��. ;� .- - ------- � � �,, -.\• `• `'�, �, ._ ---------� � ��, �'•��;�;�� '� '� �,`, ---- �\ — — -- — 3 �� � � �4y ``\` , } ��, , �, , ��� � y � � 1 1 \ . x � � � `�� � , , , � , , , , , , , , . , , ; � , t ; � �, �, �, � � , �,, � � �� `� � `�., ------------ - _ \\ ry. i i ,� •-- `�`. � '----------- `��e 4, , � , , . _ � � . , , , �, � ; ; 1 I 1 1 '•, ' 1 • � ., ,, � �, ', � � � t ' •'•.•• ��. ' - -.._. � i > > ,_ _ �� • . __ � � i � � -- `� � i ; ; .. �.� '• `�� -^-- ' _ ' ~ 1 � _ _- i R � `��� ``� _ - `,�� �\ ; ; '�, .' ;,: :; �� _, - '�, -- T� 3 5 � , , , . . , , , , , , . , . , , � �, , . . �, � : ; I I ; I ,,1 .' �` .. , � . � � ; �� � � � 1 1 ,1� / � - `/ \ , , � , _--. . , �i' ;, �� ; � � r � ..__�, �� '� _ _ C� '�+ 50� PARCEL � � _� �� �, c��J S E = II �, ` ---- J ' _ .� \ �I`` ` '` •-----. '�.� .----•-_�` - , :__ _ _ _ - _ _ _ '���-"i \\ �� � ti - � ', - -•�4. ��. ----------- -_ �._'_ `� '` .r:�` � -a � - ��'•• _ --- - `�.'�... `.`,� � .. l � . ��'4+------ ----•-- -. � ` ��,. � � �' `� ',�`�G'-�����'•-- - � , `,"" `�`�'�'�, �b \�� �� \� � � �.,`,��•• ,,�• ,,�tb �� �`• ----- ��J�b.' �,1��' `�` O � °�' � , ��` �`�`� ��\ '----_-- _ �s�,,_ . `\`,��: ',' �� .\\ �'�. � � �'•-_.�' b � -- 'Fb� \, --- `^�b_� ._ � `,�,, \ � �'� �\ � - .._, _ - ��----- � "- �� , ' `�3 � �' i � � - ' - •'•. '• � `9 t � �1 ��\ ,` � " __ \. `i, � ,� A ' . � 1 - �•�,, ' _ ``�1 '. �•',r��`�. -�`+ `,O' ', �-- - -- - ' - ._,_� \� �_ ''9� - � '.�'•,�`�\���\ �\` '� �. ___;\,,'. � --',k. � � � ' � --'-\_-'-_ ���'_ =yS ' • FOREST 'i= 1.71 AC ' .� �s8e�s o_ �i.'s T _: � �� • � - -- GRASS - 0.36 AC : �'' x � �' � � 4 LOTS �- 0.27 AC>D.3(p��' - ; 1/2 ROAD j= 0.09 AC ; � � � � ' � ' . . � -'' \ � � yd �JT 3 _�i�.� _ . ; -C�vt� :.QE=:� ?ARK � `�` '-ar_ �. �o.5�' , � , .�" , � `.ao " Q h FS lTE!�{ 0 N F Y R��'� ;�A R K . _. ,� , . , � ._ ` � ._ __ : , � , . , , n ,____._. ., ____ ____ � _____ _____ , __.. -- — _ ._ _ .�-- � '• �°:�1����f- �� ' ° A=2. 43AC. TOT. ;' _ _ .� �� , EXI S TlN G � �-------------------�- � 4... - -..-3..--...-.�.................................: CONDITIONS '��� ,�.�..�, - a � n,,��.°"`5�..: :��,.:, . G.4.1 VVETPONDS—RASIC nND LARGE—METH(7DS nFANALYSIS FIGURE 6.41.A PRECIPITATION FOR MEAN ANNUAL S7'ORM IN INCHES (FEET) ST 1.0/ ��� 1 2 ST 1 .1 ST 1.0 LA 0.8 LI�. 0.9 LA 1. 0 J ,�;�:� � :� , , r: -�, � ..,, .,, --- ,-, , -, �-;�'�� �,' ,� i_ ,, i ;�; � , f ; � 1 -� ''� e . i_ � +�,:1 ; i` � r f,_ ;_ _i i �.��` �� � = � �' > � �� -� � ; �} F �.:_ --f� � `� ,�-, a -� �,: y � � ��' !'� ;—–l �'`_, r ` �" r�:; ��-t1 � �` J ' t'_ �' � ''� _; k -;� r ��\ -- / 8 _ , �I� �� 1� r: { ' �' .. t, _...��'f'��__ ' i� ' �� - ` •i � d _-, �� t f I " i , ... ' ' �� .,� � i t ., r '�� ' i .f � ��..� J � �' � yi�,;[113at � .� .�l � �?F V��.c �O. -t>- �. 1V'. r aF .;t�a� T•' :,^. .. '`• '� ,� . 4 � ��r � .! ��. �.J ; I I�, �:r,f ,��, . �:.: .�--?`�, `T.j., -1 � ,, , � �L' ` , , �, � _7_ C� �� 1 � , . , ti � J.�;�.� h�;r ` � i `% ----�� �Y�= �.. �,} � .� �s i �� } .,, / _ _ b.r '�/ ?- � ^. i .r� .�'��; i. i r 1 hl tR�.x' - ,} 1 � � _ �� •.�"� � t,i � ' ,�. f " . �Y_f P yY ;�� �� .�', + .i• � r� .. I`, � L �C C _#.' _ �.'_..�• ` ' " 'iF ''L ;') �•��`-, -�r' . �. ,� �Lli� iK►Ih��^ t ... } ���,�f4r, q,,µ 'r ,r '� _ .' � .' r ,�,� .u,.� ' ��� , 5 l T� � ry.r �,' ' ' ' � � -�, � � y �s� - - . �'--� �� J� ~\ � � � � r � ._ � �� � �' __ 3 rr �� �/ f �i.i� �` � %. �. € � ,t ` , , ; , . , r1 ' �� �+' 3A� :i,� �� l' 4 � V � \ _` rl v�.,•_ � ' . � = � . � , , � 3,`' . ���v' �..._. �--- . ��+ t � t� r S'T 1 ,! -r' �,. .... � � 4 ;, . ,_ t5 , ' : - li ,�4 ?w+c .._ / ��� :, � � .� , k: so�! �`� �'---- i f�_i � . !. ; a - s . . — � , i���-i' :f� �, ri �' t t : � � c� �d g �� } �� � �y � J � / 3}��'P \ / � S�I ��� \ � ��-. • i �.c� �`��✓ ` 8,- f�,. -Y` �� ;� i d� - ' i ��L" � ,a, r _ � ��. 0.54„ , ,�l :;�t� a -.� �` (0.045' � . �f e/(1.:.:��.-in�Ka,.��e:tr ? - h 0.47• ...._. <�..,. + 1_ (0.039' ) �, - � '-_ __ t l_;^_j C-=__; IncorporatedArea � ' � RiveNLake 0.47" �-=� � ? -- Major Road (0.03 9' ) 0. 52" •, � - � =�„•_ (0.043� ] ,���_ 0.65" NOTE:Areas east of the eastemmost isopiwial shouid use 0.65 0.5 5" (0 . 0 5 4' 1 inches unless rainfall data is avaNable for the location of interest �� �,�� , � ��Tha mean ennual stonn is a canceptual stortn tound by 6vid'mg Ihe ennual precipilalion by the total number af stam eveMs per year result,generates large amounts of runoff. For this appiication, till soil types include Buckley an� bedrock soils,and alluvial and outwash soils that have a seasonally high water table or are underlaiT� at a sha(low depth(less than 5 feet)by glacial till. U.S. Soil Conservation Service (SCS) hydrol�gic sr,il groups that are classified as till soils include a few B, most�, and all D soils. See Ctiapter 3 fc>r classification of specific SCS soil types. 1998 Surface Water Design Manual U/119R � ��,� �, ��, V. CONVEYANCE CALCULATION The calculated 25 year and 100 year peak flow from this site using the modified rational method are 2.67 cfs and 3.15 respectivley. It appears that the piping system will be able to carry the required flo�vs in the 1?" pipes. See the map and calculations �r� the fc�llo��in�� ��a�es �f this report The f'ollowing calculation indicates that any pipe over 1°io will carry 3.8 cfs I�herefi�re thc: I?' diameter outfall pipe will be adequate for the 3.l 5 cfs for the 100 year peak shaNe . . . . . . . . . . . . . . . . . . . . . . . . . . . Circular Solving for . . . . . . . . . . . . . . . . . . . . . Flowrate Diameter . . . . . . . . . . . . . . . . . . . . . . . . 12.0000 in �epth . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2500 in Slope . . . . . . . . . . . . . . . . . . . . . . . . . . 0.0100 ft/ft Manning's n . . . . . . . . . . . . . . . . . . . . . 0.0130 Computed rtesul ts: Flowrate . . . . . . . . . . . . . . . . . . . . . . . . 3 , g C F S 3.8325 cfs -�— Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.7854 ft2 wetted Area . . . . . . . . . . . . . . . . . . . . . 0.7650 ft2 Wetted Perimeter . . . . . . . . . . . . . . . . 31.6348 in Perimeter . . . . . . . . . . . . . . . . . . . . . . . 37.6991 in velocity . . . . . . . . . . . . . . . . . . . . . . . . 5.0101 fps Hydraulic Radius . . . . . . . . . . . . . . . . 3.4821 in Percent Full . . . . . . . . . . . . . . . . . . . . 93.7500 % Full flow Flowrate . . . . . . . . . . . . . . 3.5628 cfs Full flow velocity . . . . . . . . . . . . . . 4. 5363 fps Pg. – 21 Er,i,E-Ra.ira-sP.Poc , �.� ,.TL 3 5 � � �.��.,;� ►' `� , . � �����:� �� � ' �z' - --- -. NOR TH ,���-. . .. �.� ��.� �, �s= -_ __ _. � ., � ,' '';� `, '�, -� �� �"=5a' i li \ �I `c-- .._ ._ _ , � ' � t� 'A �� `,I � - �— \ S8B'14'J2'c i4 � ! 11 � � \ � � ' �,,1, ��,, , �`\, •.'� � , - \ , , , , � , , � , � , , , - � . � � , } ` '. �' � ' \ . � , . , , , , , , , , , � , . , � i �` ', ,,�` � '•. �._---- � 5„ �� '� �� �� ',��--'•., "►�'E'Q'�'-"--, ���e � ' � •`'•� �t �t ���--12� .,r------- -- ���'V�' , , , ����'�. � ' � � .. ,,�:, � �`. -5=25.4 .1E=332.09_ ` �� . ; i `�., ` " ,':. '74�`5'�A�, `� i � � •. . •,..+r •.r•- � �. � +� •��., -.,� .;-�,,,�, ,,��,,. _ � TI 3 i ' ` - , � , , ,.,�, ��---. ;:,. ,, � � A . ,A=!0.73�C ---�---- ----'�__,�;•- ----- }�� , ''--- 1E�368;00 ' , _ -- - �r - --- , , � -, �+ ----------- - -- - -- j �;\ � - , i ; •- _ _ ' - ` � ' '' --- `. •• .��-..__ - _ _ _ - -_ ., `� � � '\�� ----- --,�y�'- ��, •�11_� '- _"- -- ..:. -- ��,�... �`.� � �, , � • �' -�-- - - •-_. _� � � , _ ,�•.. _ .,� > - ----- '�'-._. - �` , `. � �� ` ��� '•, --� --- ��''• - `�`��+..,,;�, •. ���\`` �„��\ . ' - _ '�-. • o,� j -- __ �. ��' �}. .,\ -�� _ ``\�' '��. �,� �. � --- ,.�pj'�,�4.�.���.,, � ..,� _ �'� _ - �.�.�� '�,._ ��. �' �;,�\ .\\. s�2s5�', � _ ,�b_._ _ -- .f`--. �� �� '$ �' N . IE=J85. / �,�84.40 ,� __- _- �� • '•. �y'�� ��� , ,;y^�` _ _ - , ! ' j r� ,,�,�'f����'� �' � � _ _ _� r' —� � �. $ �\ � - '�.,,,'-�-��� �;�`,_,�i�r_ � CB�� � i � — —,. �- �--' ..r,` A=0.41 AC 4 �CB,�lZ s , � ''s`ae�1a;� s�''�;- - •5�� � '�A=O:�OAC � , � �� Y x �, � :��ar--j-; ; ' ,, _� . ; i � . . , '` ? ! __ .,�' d" ���� ..� , '_'±' � � _�r � -C,V��' ��iE�< =aRfC � i �� �-,�,, � . ._.� - +'°° _ ' ` -�%' ',` -1 r-C�,( D � !� =- � _ _. _. _ . �� .. �� ._ ._, __ . � ,�.� �ON11/E YA NCE _% a _ � _ _- — --- --_ =�- — --- — -- �At�t�t�Fl9-�lS_ d ----=✓ ' . � � ` . �".q9 . �� .. ] �� , __�Y._ '_"' Pipe Report . Pipe Upstream Downstream Inlet iniet Inlet Total System Discharge Length Constructed Section Roughness Capacity Upstream Downstream Upstream Downstream Node Node Area C CA CA inbensity (cfs) (ft) Slope Size (cfs) Invert Invert Ground Ground (acres) (acres) (acres) (in/hr) (fUft) Elevation Elevation Elevation Elevation (ft) (ft) (ft) (ft) P-1 I-1 I-2 0.41 0.60 0.25 0.25 2.73 0.68 34.00 0.026471 12 inch 0.013 5.80 385.30 384.40 388.50 388.42 � P-2 I-2 I-3 0.20 0.60 0.12 0.37 2.69 0.99 111.00 0.147748 12 inch 0.013 13.69 384.40 368.00 388.42 371.25 ; P-3 I-3 I-4 0.73 0.50 0.37 0.73 2.55 1.88 62.00 0.258065 12 inch 0.013 18.10 368.00 352.00 371.25 362.00 P-4 I-4 OuUet 0.55 0.60 0.33 1.06 2.50 2.67 5.00 0.100000 12 inch 0.013 11.27 352.00 351 50 362.00 351.50 I � - y G�{r� G t�:�G.L, _ /. ��.. Z <� l � �� �ro�ect Title: ELLE RAIN ?ro�ect Engineer. Mounir Touma ;:\haestad\stmc\elleram.stm Touma Engineers StormCAD vl 0 �7/23/03 14:36:46 Haestad Methods, Inc. 37 Brookside Road Waterbury,CT 06708 (203)75�1666 Page' of 1 Pipe Report ?ipe Upstream Downstream Inlet Inlet Inlet Total System Discharge Length Constructed Section Roughness Capacity Upstream Downstream Upstream Downstream Node Node Area C CA CA Intensity (cfs) (ft) Slope Size (cfs) Invert Invert Ground Ground (acres) (acres) (acres) jinRx) (ft/ft) Elevation Eievation Elevation Elevation (ft) (ft) (ft) (ft) P-t I-1 I-2 0.41 0.60 0.25 0.25 3.19 0.79 34.00 0.026471 12 inch 0.013 5.80 385.30 384.40 388.50 388.42 , P-2 I-2 I-3 0.20 0.60 0.12 0.37 3.14 1.16 111.00 0.147748 12 inch 0.013 13.69 384.40 368.00 388.42 371.25 �-3 I-3 I� 0.73 0.50 0.37 0.73 3.00 2.21 62.00 0.258065 12 inch 0.013 18.10 368.00 352.00 371.25 362.00 �-4 I-a OuUet 0 55 0 60 0 33 1.06 2.94 3.15 5 00 0.100000 12 inch 0.013 11.27 352.00 351.50 362.00 351.50 � , ,;_ .�'r��L ,,� � N � �ro�ect�itle: ELLE 4AIN Pre�ect Engineer Mounu Touma lhaestad\stmc\ellerain s,m Touma Engineers StormCAD �1 C ,��/C3 '4 4��8 -aestad �Aethc�s nc 3�9rookside Road Waterbur, CT 06708 �03i-�5-'�5 ?age ' cf ' DOT Report � Pipe -Node- Inlet Inlet Tohal -Ground- -HGL- -Slope- -Section- -5ection- Length Average Description � Upstream Area CA CA Upstream Upsfieam Energy Discharge Shape (fU Velocity Downstream (acres) (acres) (acres) Downstream Downstream Constructed Capacity Size (ft/s) (ft) (ft) ��) (�) P-1 I-1 0.41 0.25 0.25 388.50 385.64 0.025787 0.68 Circular 34.00 2.51 I-2 388.42 384.82 0.026471 5.80 12 inch P-2 I-2 0.20 0.12 0.37 388.42 384.82 0.147066 0.99 Circular 111.00 2.63 I-3 371.25 368.58 0.147748 13.69 12 inch P-3 I-3 0.73 0.37 0.73 371.25 368.58 0.257528 1.88 Circular 62.00 3.57 I I-4 362.00 352.70 0.258065 18.10 12 inch P-4 I� 0.55 0.33 1.06 362.00 352.70 0.100000 2.67 Circular 5.00 4.54 � Outlet 351.50 352.20 0.100000 11.27 12 inch � - � �' �� i � Y �� � � -v � � � � v� �roject Title: ELLE RAIN Pro�ect Ergineer Mounir Touma ::�haestad�stmc\ellerain.stm Touma Engineers StormCAD v1.0 07l23/03 14:39:08 Hacstad Methods. Inc. 37 Brookside Road Waterbury, CT 06708 (203)755-1666 Page 1 of 1 DOT Report Pipe -Node- Iniet Inlet Total -Ground- -HGL- -Slope- -Section- -Section- Le�gth Average Description • Upstream Area CA CA Upstream Upstream Energy Discharge Shape (ft) Velocity Downstream (acres) (acres) (acres) Downstream Downstream Constructed Capacity Size (ft/s) I, (�) (ft) (�) lcfs) I P-1 I-1 0.41 0.25 0.25 388.50 385.67 0.025722 079 Circular 34.00 2.63 I I-2 388.42 384.85 0.026471 5.80 12 inch P-2 I-2 0.20 0.12 0.37 388.42 384.85 0.146999 1.16 Circular 111.00 2.77 I-3 371.25 368.64 0.147748 13.69 12 inch ' P-3 I-3 0.73 0.37 0.73 371.25 368.64 0.257490 2.21 Circular 62.00 3.82 I-4 362.00 352.76 0258065 18.10 12 inch P-4 I-4 0.55 0.33 1.06 362.00 352.76 0.100000 3.15 Circular 5.00 4.91 Outlet 351.50 352.26 0.100000 11 27 12 inch iu � -_ y�Ai' ��� - 2 (s Project Title: ELLE RAIN Project Engineer.Mounir Touma c:lhaestad�.stmc�ellerain.stm Touma Engineers StormCAD v1.0 07/23/03 14:41:32 Haestad Methods.Inc. 37 Brookside Road Waterbury,CT 0670� (2(�)7�r16F� Paye 1 of t • � � � , • ,.� _le ------ ---- --------------- F?e:_�� n�_ �ia �_a���a�a�ic n � ��� . Discharye: O. r� cfs at node I-1 • Discharge: 1.00 cfs at node I-2 Discharge: 1. 95 cfs at node I-3 � ��1 Discharge: 2 .81 cfs at node I-4 Z'�� � r Discharge: 2 .81 cfs at node Outlet Beyinning iteration 1 Uischarge: 0. 68 cfs at node I-1 Discharge: 0. 99 cfs at node I-2 Discharge: 1.88 cfs at node I-3 Discharge: 2. 67 cfs at node I-4 Discharge: 2 . 66 cfs at node Outlet Completed iteration 1 Current discharge convergence relative errcr : 0 . �3,5i5��e-' Target discharge convergence relative error: 0 .001 Beginning iteration 2 Discharge: 0 . 68 cfs at node I-1 Discharge: 0 . 99 cfs at node I-2 Discharge: 1 . 38 cfs at node I-3 Discharge: 2. 67 cfs at nede I-4 Discharge: 2 . 67 cfs at node Outlet Discharge Convergence Achieved in 2 iterations : relative error: 0. °500�?69e-� ** Warning: Design constraints not met. Violation: P-4 does not meet minimum cover constraint at downstream end. --------------------- �alculations Complete --------------------- �* Analysis Options * ` Friction method: Manning's Fo=mula HGL Convergence Test: 0.001000 Maximum Network Traversals: 5 Number of Pipe Profile Steps: 5 Discharge Convergence Test: 0. 001000 ?�Iaximum Desian Pa��e� : 3 " --- ---- ---- - - tJ�' .,,�C-L"}: ';�UiC}C V12`,�' ------ ---- I Hydraulic Grade � L��hel I Length � "i_�e I Discharge I Upstream I Downstream 4 F-_ 3� . 00 12 inch 0 . 68 3°5. 64 3°4 .82 P-2 111. 00 12 inch 0. 99 3°4 . 82 368 . 5° P-3 62.00 12 inch 1. 88 368 .58 35L.70 P-4 5. 00 12 inch 2. 67 352 .70 352 .20 I ----------- Elevations ---------------- I Label I Discharge � Ground � Upstream HGL I Downstream HGL � I-1 0. 6° 3°8 .50 385 . 64 3°5. 64 L-2 0. 99 388 .42 384 . 42 3�4. °2 �-3 1 .88 371.25 368 .58 368 .58 ��utlet 2 . 67 351.50 352 .20 352 .20 �-4 2. 67 362.00 352.70 352.70 Flapsed : n m�nu�P !s) ': sec-�nd (s) �� - Z 7 Project Title: ELLE RAIN Project Engineer Mounir Touma r,:lhaestadlstmc�ellerain.stm Touma Engineers StormCAD v1.O 0723A73 14:34:08 Haestad Methods, Inc. 37 Brookside Road Waterbury,CT 067(� f2(Y3)7��,-7F�F,(i Paqe 1 ot 1 ------------------ Beqinning Calculation Cycle ------------------- • Discharge: 0 .?9 c�s at node I-1 • Discharge: 1.17 cfs at node I-2 Discharge: 2.29 cfs at node I-3 Discharge: 3.29 cfs at node I-4 Discharge: 3.29 cfs at node Outlet Beginniny iteration 1 Uischarge: 0.79 cfs at node I-1 Discharge: 1. 16 cfs at node I-2 Discharge: 2 .21 cfs at node I-3 � (�('- y���l Discharge: 3 .14 cfs at node I-4 Discharge: 3 . 14 cfs at node Outlet Completed iteration 1 Current discharge converaence relative error: 0. 48304°61e-1 Target discharge convergence relative error: 0 . 001 Beginning iteration 2 Discharge: 0.79 cfs at node I-1 Discharge: 1. 16 cfs at node I-2 Discharge: 2 .21 cfs at node I-3 Discharge: 3. 15 cfs at nocle I-4 Discharge: 3 . 14 cfs at node Outlet Ui.scharge Convergence Achieved in 2 iterations: relative error : U. �?S19F7�?e-� ** Warning: Uesign constraints not met. Violation: P-4 does not meet minimum cover constraint at downstream end . --------------------- Calculations Complete ---------------------- ** Analysis Options ;; Friction method: Manning's Formula HGL Convergence Test: 0. 001000 Maximum Network Traversals : 5 Number of Pipe Profile Steps : 5 � Discharge Convergence Te�- : ' . '��n'���'� Maximum Design Passes: :' ---------------- Network; �uicn V�- .: � Hydraulic Grade � , Label � Length I Size � Discharge � Upstream I Downstream I P-1 34 .00 12 inch 0.79 335 . 67 389 . °5 P-2 111 . 00 12 inch 1.16 384 .35 363 . 64 P-3 62.00 12 inch 2.21 363 . 64 352 .7h. P-4 5.00 12 inch 3. 15 352.76 352 . :�F � ----------- Elevations ---------------- I Label � Discharge � Ground � Upstream HGL � Downstream HGL I I-1 0.79 388 .50 385 . 67 385. 67 I-2 1 . 16 388 .42 384 . 85 384 . 85 I-3 2 .21 371.25 368 . 64 368 . h4 Outlet 3 . 14 351.50 352.26 352 . 26 I-4 3 . 15 362.00 352 .76 �5? . 76 Elapsed: 0 minu}e (�) '_ second (s) I�a - z � �J Project Title:ELLE RAIN Project Engineer:Mounir Touma c:lhaestad\stmc�ellerain.stm Touma Engineers StormCAD v1.O 07/23A�3 14:40:44 Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06706 (ZOCi)7�r1666 Page 1 of 1 • Sheet1 �_ _ _.. __ - _ JOB NAME: ' f ELLE RAIN I -- -- __ _ _ - ---- - - - _ --- �MODIFIED RATIONAL METHOD t ___ ; _ � -- - � , -- --- __ _ _ _- _ _ _ - --- _-- �_-- ---j_ --- - i-- - ------ r � ----- � i ---- ---1--- - - -- _ _--- ___ __-- - _ ---- P2 2.00 TOTAL PRECIPITATION - - -- -- - - _ - -- - --- _ - -- - -- P5 0 00 IN INCHES� --- --- - - __ __ -- --- - -- -__ - P�o 2 90 _--- - - __ . ----- --- -- -- --- -- - - P25 _ � 3 40 � _ _ -- - __ ----- _ --- -- i P5o 0.00 � - � - -- ! _ ___ --- _ __ _ _ i P�oo ' 3.90 - ---_ TIME 1 _ f - MIN. � 2-YEAR 5-YEAR 10-YEAR 25-YEAR � 50-YEAR 100-YEAR - - - -0.- -- - 1.09. _ _ _ -- - - -- : ' 0 00 2.18 2.73 0.00' 3.19 '. _ - -- - -- --- �-- ___: -- - 6.3i 1.09 0.00 2.18 2.73� _ __O.Od1_ 3.19 ; _ ------- - - - _ - 10 i 0.83 0 00� _ 1.62 2.02 0.00� 2.39 - ---- --- - - -- - _ __ _---_ -- 151 0 66 0.001 1.25 1.56 Q.00 1.85 _ 1- - - -- - --- - - _ -- --- --- - _--- 2Q� 0.56 0.00 1.04 1.29 0.00 1.54 - _ _ -----_ _ - _ __ ---- 25 j 0.49 0.00 0.90 1.12 0.00I _ 1_34 -- -- - -- -- ---- -- -- ---- - 301 0 44� 0.00 0.80 0.99 0.00 1.19 _ -- -- -- - - - __ -- -- - -- -- ---- --- 40 0 37 0.00� 0.67 0.82 0.00 1.00 _-- - __ _- __ - --- --- 50 0 33 0 00 0.58 0.71 0.00 0.87 - - -- --- - - - �--- - - -- _ _ _ 60 0.29 0 00 0.51 0.63 0.00 0.77 _- -- _ --- -- -- r-- _- - _ -- ---- 80 0.25; 0 00 i 0.43 0.52 0.00 0.64 - ----- - - - + _-- - --+------ -------+--- --- --- - 100 0.22 0.00' 0.37 0.45 0.00 0.56 --- --- -- __ _ _ _ _ _-------__ _;. _ _ _ _._ __ _ _ _ _ _ _ _ I Page� � � • Rainfall Table Return Periods Durations 10 year 25 year 100 year 0.1 min 2.18 2.73 3.19 6.3 min 2.18 2.73 3.19 10 min 1.62 2.02 2.39 15 min 1.25 1.56 1.85 20 min 1.04 1.29 1.54 25 min 0.90 1.12 1.34 30 min 0.80 0.99 1.19 40 min 0.67 0.82 1.00 50 min 0.58 0.71 0.87 60 min 0.51 0.63 0.77 80 min 0.43 0.52 0.64 100 min 0.37 0.45 0.56 Rainfall Intensities are in (inlhr) j� , "_ ?�� Project Title: ELLE RAIN � Project Engineer:Mounir Touma c:lhaestadlstmclelle rai.stm Touma Engineers StormCAD v1.0 0722/03 10:21:48 Haestad Methods,Inc. 37 Brookside Road Waterbury,CT 06708 (203)75G1Fi66 Page 1 0(1 V1. SPECIAL REPORTS AND STUDIES I � Pg. - 31 elle-rain-sd.doc I V11. BASIN AND OTHER COMIVIUNIT�' AREAS Pg. - 32 elle-rain-sd.doc VIIL OT'HER PERMITS Structural permit for the concrete wall for the detention vault. Residential Building Permits Pg. — 33 elle-rain-sd.doc IX. EROSION/SEDIMENTATION CONTROL DESIGN The temporary erosion plan will be designed to the requirements of the 1998 King County Surface Water Design Manual. The silt fence and silt trap are placed to help reduce the chances that any construction related silty runoffwill leave the site and affect downstream facilities. The amount of cleared area for road and site construction will be similar to the 2-year developed peak, which will produce a peak flow of about 0.34 cfs. From pages D-26 and D-27 of the 1998 Appendix D Erosion and Sediment Control Standards a sediment trap for less than 3 acres development should contain a minimum surtace area at 3.5' depth to allow settling of the silt particles. The minimum surface area is to based on the formula; SA = FS (Q2/VS) where FS = Safety Factor= 2.0 QZ = Peak 2-year developed flow (0.46 CFS} V2 = Particle settling velocity= 0.00096 f1s SA = (2) (0.46) / (0.00096) = 957 SF. Required 3:1 side slopes 355.5 0'x27' bottom 356 2' x 30' 357 8' x 36' 358 14' x 42' 359 20' x 48' SF at 3' deep 960 SF overflow el. 360 26' x 54' top of berm The sediment trap should be constructed on the lower portions of the site. Pg. — 34 elle-rain-sd.acc . 1X. BOND QUANTITIES NONE INCLUDED Pg. - 35 �I elle-rain-sd.doc �i i . � 1�-1AINT'E\ANCE .AND OPERATIONS NONE WC:LUDED Pg. - 36 elle-rai::-sd.do-