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Drainage Reports - 10/14/1994 (2)
OF T -u"xzur== -L BRITTANY KNOLLS FILING NO. 1, PHASE 1 FINAL DRAINAGE STUDY AMENDMENT DRAINAGE STUDY TO KELLOGG ENGINEERING, INC. 1986 REPORT 1 1 1 BRITTANY KNOLLS FILING NO. 1, PHASE 1 1 FINAL DRAINAGE STUDY AMENDMENT DRAINAGE STUDY 1 TO KELLOGG ENGINEERING, INC. 1986 REPORT 1 1 .. Prepared for: 1 COLORADO LAND SOURCE. LTD. 8101 E. PRENTICE AVE., SUITE # M-180 1 ENGLEWOOD, COLORADO 80111 1 AUGUST, 1994 OCTOBER, 1994 REVISION 1 1 Prepared by: JR ENGINEERING, LTD. 4812 South College Avenue 1 Fort Collins, Colorado 80525 1 Job Number 9005.00 1 i 1 I JREngineering, Ltd. 4812 South College Avenue Fort Collins, Colorado 80525 (303) 282-4335 • FAX (303) 282-4340 October 11, 1994 Mr. Basil Hamdan Stormwater Utility City of Fort Collins 235 Mathews Street Fort Collins, Colorado 80524 4935 North 30th Street Colorado Springs, Colorado 80919 (719) 593-2593 • FAX (719) 528-6613 6110 Greenwood Plaza Blvd. Englewood, Colorado 80111 (303) 740-9393 • FAX (303) 721-9019 ' RE: Brittany Knolls Filing No. 1, Phase I - Drainage Report Review Comments ' Dear Basil: ' We have reviewed the comments for the above referenced drainage report. The following discussion addresses all comments and includes a review of our findings and the results of a meeting with you on October 7, 1994. LOCATION tThe Brittany Knolls Filing No.1, Phase I, is located in the Fossil Creek Basin. (See Figure 1 - Vicinity Map.) ' DRAINAGE EASEMENTS ' The drainage easements for backyard swales has been addressed by a "Deed of Dedication for Easements". A copy of this document is included in APPENDIX A-1, attached to this letter. At the time when the Deed is recorded, we will provide you with a signed copy for your files. GRADING PLAN / DRAINAGE PLAN Information has been added on the Grading Plan to the "Typical Lot" details showing the finish grade to be at a minimum of two percent (2%). A note has been added to both the Grading and Drainage Plans stating that the property owners must maintain all swales. (Revised copies of the plans are ' included in the back of this report.) FLOWS BY-PASSING INLET ' As you requested, we have reviewed the flows in Brittany Drive, primarily looking at the existing ' W90050MR_ADDIMM '�3 Recycled ' Mr. Basil Hamdan October 11, 1994 ' Page 2 outfall system. Based on our review and calculations, we have determined that: 1. The adequacy of the existing outfall system is controlled by the 18" RCP outfall pipe connected to the existing inlet in the northwest comer of Brittany Drive and Buchanan Street. ' This is due to the size of the pipe and the limited amount of head available (said inlet has a field measured depth of two feet (T) from bottom to flowline). ' The following table summarizes the attached calculations: n * All pipes are 18" RCP ** At this location, the head required to get the flow into the pipe is greater than the existing head. At the inlet in the northwest corner of Brittany and Buchanan, the headwater depth required is greater than the headwater depth available. Therefore, the pipe will only accept the flows for 2.5 feet of available headwater. For HW/D of 2.5/1.5 or 1.67, from Chart 2 (attached), Q = 10.8 cfs. The remaining 1.38 cfs (12.18 - 10.8) will by-pass the inlet in the street. As shown in the attached calculations, the total by-pass for the 2-year storm is 2.64 cfs. The total by-pass for the 100-year storm (not shown in the attached calculations) is equal to: (the 100-year by-pass shown in the Kellogg Report) + (the additional flows generated as a result of the revised "C" values for Brittany Knolls Filing No.1, Phase I) - (the B: 900S00\DR_ADD1.WM I 1 L [1 1 Mr. Basil Hamdan October 11, 1994 Page 3 piped flows with a total headwater depth of 2.5 feet) _ (39.25) + (5.77) - (10.8) _ 34.22 cfs. As the attached calculations show, Brittany Drive has adequate capacity to accommodate these flows. (See APPENDIX B-L) 2. The flows by-passing the aforementioned existing inlets continue easterly via street flow in Brittany Drive to Lemay Avenue, then northerly on Lemay Avenue to an existing sump inlet. In the Drainage Report for Brittany Knolls Filing No. 2, prepared by TST and Lidstone & Anderson (copies of excerpts from this report are included in APPENDIX C-1), the calculations show that the street capacity and outfall system are adequate to accommodate the flows in this area. As we discussed in our meeting of October 7, the existing street and outfall system is adequate to accommodate the additional flows generated as a result of this site (an increase of 1.58 cfs for the 2-year and 13.47 cfs for the 100-year) (See APPENDIX C-1 for calculations.) SUMMARY A. As a result of this review, we have determined that any additional inlets would not be required and, in fact, the existing outfall system would not be able to accommodate the flows intercepted by an additional inlet. B. The existing streets and outfall system are adequate to accommodate the flows generated from this site. If you have any questions or comments, please do not hesitate to contact me at 2824335. We hope that with the attached additional data, the construe will be approved in their entirety. Sincerely, JR Engineering,)Ltd. Dave Klockem P.E. For and On Behalf of JR Engineering, Ltd. Attachments ' cc: File BA900500\1)R_ADD1.WM Harmony Road SITE ►-� Trilby Road FIGURE 1 - VICINITY MAP JREngineering, Ltd APPENDIX A-1 I 1 1 11 r DEED OF DEDICATION FOR EASEMENT ' KNOW ALL MEN BY THESE PRESENTS: That the undersigned Brittany Knolls Land L.L.C., a Colorado Limited Libility Company, being the owner of certain real property in ' Larimer County, Colorado legally described at Reception No. in the Larimer County Records, in consideration of Ten Dollars ($10.00) in hand paid, receipt of which is hereby ' acknowledged, and other good and valuable consideration, does hereby dedicate, transfer and convey to the City of Fort Collins, Colorado, a Municipal Corporation, for public use forever a permanent easement for stormwater drainage in the City of Fort Collins, County of Larimer, State of Colorado, ' more particularly described on Exhibit "A" attached hereto and by this reference made a part hereof. It is understood by the undersigned that, by acceptance of this dedication, the City. of Fort Collins will not accept the duty of maintenance of such easement. Witness our hands and seals this day of 199_. ' Grantor r Lin Title: ATTEST: ' Title: State of ) ss County of ) ' The foregoing instrument was acknowledged before me this _ day of 199by as and ' as Witness my hand and official seal. My commission expires ' Notary Public Accepted by the City of Fort Collins on the _ day of , 199_ City Clerk ATTORNEY'S CERTIFICATE This is to certify that on the day of , 199, I examined the ' title to the property as described hereon and established that the owners and proprietors of record of the said property as construed in C.R.S. 1973, 31-23-111, are as shown hereon as of said date. ' Signed: Print or Type Name: ' Reg. No. Address: 1 1 CAOFFICEIWPW1NT TORMS\ATrNYCRT.WPD 1 I J 1 1 1 I I I p < � � o w 0 I I I I � O Of N I zz c I Z w N z O i z:2 I J ��Y c J I oN I I I I -� UWj U L �ZOU ZU inw O QYO L 0 o I W UJ L wQw 00 I I U Om L �2L0 F-m a -- ------ - - - - - - - - - - - - - - - - L-------- �- W mc6 k Zww< Q rc I --O Z O 0 Q 0C-0 w - - - - - - - r----- � NT- Na- mac— w �f I I l w Li- �� C� �Uw � z 1 1 2 O J�J J Zow- LLJ �~ o Z w V) z I I a UOZ 'I Q Ua- O LLJ_ �Q W-J I uj � m w Q cwa U Q 4 H�L w Q z Q z J% �L QQ w ¢ Lij Q zpWom Z z <�\W Q z o ~ zwzw J�oa wX wJIwm nwJ Q mOpO cr Q� �QZ LLJ LLJI a O � ---------- - � Qw��ui --------- ------ Z� F- Em W H0w wvca W m ~ m c0Ln I ------------- �arn� J Qc)O Q------- CD wwv Uo0p I I I o=wz � D — w z I w I I I I cd�ww Qp �-00 w o � cn � I I 1 1 � o �? o w �li �C c I w I I I moos w I I I z r— z i' w O Z W~JZJ z oal Q - � O Q Q U o z �n 1 I APPENDIX B-1 11 1 ,I t 1 I I 11 Engineering, Ltd. CLIENT LO'Z¢N D So uP-C.EJOB NO f 00500 JR PROJECT !�[. S BY Dw `K BY DATE / ¢ SUBJECT �!�" /�/ s f3� 1 r-r ti 7 � P • SHEET NO. / OF d ! row Qz- 7.07) T= 7--, 3 /, -7 Q D. , 22 Fro M S s 6L - (rc-:--oucT-101j F+r-.ro�) 3, 45 X D , 80 2 R,02,-7 = _ 7, /( GFS 5y- PASS 02-0 r4 (��iU/D D �f� �T� r 4 6} 55 C,c,ylg TiyP.4x = /S Fa 2 T7-//s it/d. c�lTP f' Y17:� I 1 1 1 1 1 1 JREngineering, Ltd. Q �J�NT CflLO 4W-E' S!/2GESJOB NO. 005700 PROJECT 1 ✓ T Tr' N L`5 BY BY DATE /v / SUBJECT Z Y 9 r, l TTAA.)Y D e. SHEET NO. Z OF QZ@NoZ,rPf SIr2C, o F S 7-9-i�,� C-, T - % Z 14-.0� (� 9z _ �i , % G �s c� = D , 40 sX= , S = 0.�41 1- /3, Q� 0, 38 - - O, 17 d,ssx�I,(�8= 5,3Z GF5 / _� w ,�ou.�7"rO N ��CTo� - 5�, �Z_ a, y 5 = 41 �ZGf's 4,5zcFS(�iPPE o S.l�cFs��3YPxsS) VIS JREngineering, Ltd. OLMMC0G.0 / ND SouPZ&JOBNO 9ooSoo PROJECC ��/7 TANY 1jVO4-L5 BY Dw<- H DATE �Q17�(0 9t� s,,Ecr Z I /r, Y G ew S- f,F,e / r7-A4) -/ � P St�ET NO. a OF P/oE @ DP ¢ 1'l �E @ p� FI piP� Df 2.7o F5 DES /G r /' 5� c�z S = o •o¢( Sx = o,oz Q- s -cam a Q = o,S;9 o,W Q� + v C,� o osq f o , 30 = o, 8q 1 1 1 1 1 1 1 [1 11 1 JR Engineering, Ltd. CLIENT �GO , �Nv Sue6CS LIDO Soo A `/ lOB NO. PROJECT _ 3 0-I71 /I N 7 KO o GGSQ y %J(i(/ K BY DATE 0 19 SUBJECT !i Y �� �GO(iiJ 5 /✓ Pi %%.4/�.l Y • SHEET NO. OF 4- FG01,U /NL07- & ,D.P� SE /I�zow f/�oX4 pioE & D P� 5 � TiPE FLOw. (F 5j- 8 ?d = /2, I� GAS is " AeP-avc 15�vTiD1-7 DF f3DXf i ff6le�l ro 2E C f,4-6 i ry i S ,4A-) D 4� (IU tL-L- U o Du7T J IV TO ,eirr��v�/ 0 �j ve , 1-(w Prrf - 2,5' �(w 2 . s / ( 7 C9-7 Foy /0'' r-6p = /D, 06FS rD - GFS /6Y7P4-5S To 75E A0DED TO / ZCc Cf=S F-010- 7T0r�L 03,l - PA -SS = 2 Cn 4 GFS Fo �?- Z YEfiP- 570 2M . No Text No Text No Text No Text No Text CHART 2 ISO 10,000 168 8,000 EXAMPLE (2) (3) 156 6, 000 D•42 inches (3.5 feet) 6• 6 144 5,000 D•Izo ds 6• 5• • 5. je 4,000 h1we Nw 132 3,000 D feet 5' 4• 120 (1) 2.5 6.8 (2) 2.1 7.4 4. 2,000 4• 108 (3) 2.2 7.7 3• ' 96 eD in feet 3' 3• 1,000 800 ' 84 600 --� -- 500 / 72 400 ; 2. N = N 300 �Y /) 91/D N 1.5 ' Z Z 60 u 200 / 1.5 V S4 a '7 J 48 � //Q 0Q 0 42 0 60 ;- /1 .. W 1.0 1.0 LL c N 50 HW ��� ENTRANCE 40 p SCAtE' ,TYPE- rc W 1.0 t- 36 30 (1)• Square edge with 4 9 9 W Q33 headwall 9 QQ / 12 j - Groove and with W 30 / headwall 2 .8 .8 ice' (3) Groove end •8 ' 27 / projecting 24 7 7 r 6 To use scale (2) or (3) project 21 5 horizontally to scale (1), then 4 use straight inclined line through D and 0 scales, or reverse as 3 illustrated. •6 •6 ' Z i 2 , ' 15 .5 5 1.0 .5 ' 12 HEADWATER DEPTH FOR CONCRETE PIPE CULVERTS ' HEADWATER SCALES 2a3 �. REVISED MAY1964 WITH INLET CONTROL BUREAU OF PUBLIC ROADS JAN. 1963 S-22 ' ��s Worksheet Worksheet for Irregular Channel ' Project Description Project File n:\brftl.fm2 Worksheet BRITTANY DRIVE - HALF STREET ' Flow Element Irregular Channel Method Manning's Formula 1 Solve For Water Elevation ' Input Data Channel Slope 0.021000 ft/ft Elevation range: 99.50 ft to 100.17 ft. Station (ft) Elevation (ft) Start Station End Station ' 0.00 100.17 0.00 4.00 4.00 100.09 4.00 8.50 8.50 100.00 8.50 34.00 ' 9.00 100.00 9.00 99.50 11.00 99.67 34.00 100.13 Discharge 9.87 ft'/s Results Wtd. Mannings Coefficient 0.016 Water Surface Elevation 99.94 ft Flow Area 2.51 ft' Wetted Perimeter .15.87 ft Top Width 15.42 ft Depth 0.44 ft Critical Water Elev. 100.02 ft Critical Slope 0.006318 ft/ft Velocity 3.93 ft/s Velocity Head 0.24 ft Specific Energy 100.111 ft ' Froude Number 1.72 Full Flow Capacity 44.78 ft3/s Flow is supercritical. 1 ' Oct 7, 1994 JR Engineering, Ltd. 11:00:04 Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Roughness 0.016 0.035 0.016 FlowMaster v4.1 b Page 1 of 1 I VS Cross Section Cross Section for Irregular Channel Project Description Project File c:\fmw\britl.fm2 Worksheet BRITTANY DRIVE - HALF STREET ' Flow Element Irregular Channel Method Manning's Formula ' Solve For Water Elevation ' Section Data Wtd. Mannings Coefficient 0.016 Channel Slope 0.021000 ft/ft Water Surface Elevation 99.94 ft ' Discharge 9.87 fp/s 100.2 ' 100.1 100.0 99.9 c 0 m 99.8 w ' 99.E ' 99.6 99.5 ' 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 Station (ft) 6, 1994 JR Engineering, Ltd. FlowMaster v4.1b 'Oct 16:10:19 Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1 Worksheet Worksheet for Irregular Channel Project Description Project File c:\fmw\britt.fm2 Worksheet BRITTANY DRIVE - HALF STREET Flow Element Irregular Channel Method Manning's Formula Solve For Water Elevation Input Data ' Channel. Slope 0.021000 ft/ft Elevation range: 99.50 ft to 100.17 ft. Station (ft) Elevation (ft) Start Station ' 0.00 100.17 0.00 4.00 100.09 4.00 8.50 100.00 8.50 ' 9.00 100.00 9.00 99.50 11.00 99.67 ' 34.00 100.13 Discharge 34.52 ft3/s Results Wtd. Mannings Coefficient 0.015 Water Surface Elevation 100.13 ft ' Flow Area 6.84 ftz Wetted Perimeter 32.41 ft Top Width 31.90 ft ' Depth 0.63 ft Critical Water Elev. 100.25 ft ' Critical Slope Velocity 0.005466 ft/ft 5.05 ft/s Velocity Head 0.40 ft Specific Energy 100.53 ft ' Froude Number 1.92 Full Flow Capacity 44.78 fe/s Flow is supercritical. 'Ocl s, 1994 16: 16:19:49 End Station 4.00 8.50 34.00 Roughness 0.016 0.035 0.016 JR Engineering, Ltd. FlowMaster v4.1b Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1 1 13/ s Worksheet Worksheet for Irregular Channel ' Project Description Project File c:\fmw\britt.fm2 ' Worksheet BRITTANY DRIVE - HALF STREET Flow Element Irregular Channel Method Manning's Formula ' Solve For Discharge Input Data ' Channel Slope 0.041000 ft/ft Water Surface Elevation 100.00 ft Elevation range: 99.50 ft to 100.17 ft. Station (ft) Elevation (ft) Start Station End Station 0.00 100.17 0.00 4.00 4.00 100.09 4.00 8.50 ' 8.50 100.00 8.50 34.00 9.00 100.00 ' 9.00 11.00 99.50 99.67 34.00 100.13 ' Results Wtd. Mannings Coefficient 0.016 ' Discharge 21.84 ft'/s Flow Area 3.55 ftz Wetted Perimeter 19.01 ft Top Width 18.50 ft Depth 0.50 ft Critical Water Elev. 100.16 ft Critical Slope 0.005480 fUft ' Velocity 6.15 ft/s Velocity Head 0.59 ft Specific Energy 100.59 ft ' Froude Number 2.47 Full Flow Capacity 62.57 ft'/s ' Flow is supercritical. ' Oct 6, 1994 JR Engineering, Ltd. 16:32:19 Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Roughness 0.016 0.035 0.016 FlowMaster v4.1 b Page 1 of 1 i 4�, ' Worksheet Worksheet for Irregular Channel ' Project Description Project File c:\fmw\britl.fm2 Worksheet BRITTANY DRIVE - HALF STREET ' Flow Element Irregular Channel Method Manning's Formula Solve For Water Elevation Input Data Channel Slope 0.041000 ft/ft Elevation range: 99.50 ft to 100.17 ft. Station (ft) Elevation (ft) Start Station ' 0.00 100.17 0.00 4.00 100.09 4.00 8.50 - 100.00 8.50 ' 9.00 100.00 9.00 99.50 11.00 99.67 34.00 100.13 Discharge 41.25 ft'/s Results Wtd. Mannings Coefficient 0.015 Water Surface Elevation 100.10 ft ' Flow Area 6.00 ft2 Wetted Perimeter 29.67 ft Top Width 29.16 ft ' Depth 0.60 ft Critical Water Elev. 100.29 ft Critical Slope 0.005419 ft/ft ' Velocity 6.88 ft/s Velocity Head 0.73 ft Specific Energy 100.84 ft ' Froude Number 2.67 Full Flow Capacity 62.57 fN/s Flow is supercritical. ' 0 'ct 16:28:58 s6: End Station 4.00 8.50 34.00 Roughness 0.016 0.035 0.016 JR Engineering, Ltd. FlowMaster v4.1b Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 Page 1 of 1 1 - IS�5 I 1 APPENDIX C-1 t 1 1 1 1 JR Engineering, Ltd. CLIENT�L42, Z-41vp 1"ooe6E oosoo JOB NO. t 4- PROJECT _ / TTA N Y F-�l D L L 5 D!N K eF' DATE /0 /O ?4- suwEcr �LO �tJ Y - PA- S S — f e / %TA/V v l/C SHEET NO. OF ' TU u T FA mot, )�--'D i N T Lows. LEAv/NG >5telT ' I e Nw forve-74"— lI-A) D 5 v G F-/A A) A-N S T� ctc--7 T ' Qy = Z, 64 GFS ( (oo = 34, 22 GFS DIFF6;?-aNCC1-36�7r�v6�E.v �u�ooe.vT )DEV, FGowS ' ANDS St%wN /.V /�936 ,�� , 0 & & ��Po,p-T /� TST/G /DST0A)E� 4NoC25OeV(IeA)9e.Po ' Ce4,0e4�ti7- Fcows <6,:4-z,0v6 /TST1 ' QZ 2, (n4 GFS /,O(0 CFS + l Sg GFS ' 0(00 34, ZZ GFS Zo17S GFS f13.¢-7 GFS CA PACITof P3zITTA-AjV 2iVE Z--e Y (F2or- -Fsr ZIr,)ST-oNE ��NOE/z-5 ckP r Z -y2 = d, GFS > Z, CDC- �00- yam/--(cFs > 3¢,2Z GFs o,K. ' G�Pf46 i TY p G EFIfA-( Fr-©M Ts r/ .14, , Sf/ow 6, 8 C FS . ' INe,EO 7-0 l4c ro / S8 GFS (ADD, GOr.j FroN Fi 4-1 ti 6, 6 .2 FIC-'oM 4F o vE Tv ' �C-,r �-.vr Q2 ;=� Q2 = S g -f /,s = 7,3E3 GA P/! G ry A n A j CFS > (-7t3E GF5 t 1 1 1 1 1 1 1 JR Engineering, Ltd. CLEENT Coco Z40v0 a�Es 900S-00 u Joe NO. PROJECT //��/TT/�/'�N�s� D w �.�.E �7 --/7o q SUBJECT rI-O (�% rJ 7 �/7 S S / / TT�%N y ��y SHEET NO. L OF Z r /DO - j TST/G LI SIVOW ,/oo = 3e, S Gas, ; Ep To �o� /�, 4"7 Cf=S 7-07�- /S (A9P1 /od%tl-G F-1,OwS l G/L./Nlr A)c?, 2 pl- 14S L F,oD� ��3o v� 7-0 GET cue Zvi Qi00 Q(mo ' - 36. S t /3, 4-7 S/, 97 (5 CAP4e,iT ° 6100 — 2fvq S > mil, 9-7 CGS �Ex�sr/NU �o' Gu2� G /-off S )2o l4 isT/ G fI Qz C,4P,4c 1 i' = Ql oo �Po�T iso.o 6F5 Q(ov -::� /S-0, v c F s > Sl, I-7 CFS = 0r-✓ Z1�9 TURE 7-'r 77 T---TLZ SHEET OF -7 cpz: -- - ---- ------i. Z. 04, I , A-1 C7 oz 7-1 �t N i 4ri4p&1-47- ir i T�i jot 1-4 -i-.- i -- r l .0-•1 unC 8 AndCc:un Inc WHER—PROJECT By, DATE PROJECT —NO. EATURE CHECKED 87 DATE SHEET, OF Ir- i v / oa =tint M we : DcsnTi4 • .. � -r. r. � I_ � ._.. .. ��_.1 —}'�� .._._p._1{.'�.._.._...1! I 1_. - tom`' I G•i3 �� L-t .._ Lo, ?3.p - S' 3_. I 2: i I j I.S.L 771. I1 16 !! . S'�� ► t— � i I I —� --L1_4�_i_ I �., .w T`. —} �--- 1 1I II f .i_JCv_ties t ij ' 1__ TJ,+S p�/ar_slopt' _Ivy �►+-. �- -- --- - , N,o1x •i w�<! I e:�k 9�s�t-ar��c�, , m out OWNER -PROJECT By DATE PROJECT NO. EATURE CHECKED BY DATE SHEET OF 7 0-47:Lotf--1 ly--off !24 7 7. its 71 aF[7LL' 7 % Ida 0,44 'IT 14. _4 41-t Jt; T_ IT - fill _74k-�O 14 �12 4— _Yj FH T 7 If T S'Z 13 1 Lld-.luny 8 Andclson Inc R—R Y DATE PROJECTN. TORE CHECKED BY DATE SHEET OF dAg _ ? —cap 4Pow P , _ I� IF IL T • I � Q jnl / /- I �...._.�•_-�—___�.. —�- .. /V _ ..._ /�V._�-.._.-Y !.�_... .. .�_(/Y, � —ITV—.T .«�. . I 1 sg io TA ��_-+--��--�--_-i,--1-_.-LT_--��- _-�_�T•-�_-1--i- i i�—! � j -i� i� i I ' ( . if I _ i 1 _r- , I I 't JR Engineering, Ltd. 4812 South College Avenue ' Fort Collins, Colorado 80525 (303) 282-4335 • FAX (303) 2824340 ' August 21, 1994 Mr. Glen Schlueter ' Stormwater Utility City of Fort Collins ' 235 Mathews Street Fort Collins, CO 80522-0580 ' Re: Brittany Knolls Filing No. 1 Fort Collins, Colorado 4935 North 30th Street Colorado Springs, Colorado 80919 (719) 593-2593 • FAX (719) 528-6613 6110 Greenwood Plaza Blvd. Englewood, Colorado 80111 (303) 740-9393 • FAX (303) 721-9019 ' Dear Glen: The attached documentation is the Amendment Drainage Study which supplements the original t Kellogg Engineering, Inc. -1986 drainage study for the above referenced project. The attached study incorporates responses to all of the Stormwater Utility concerns either as a revision to the studies and plans or by direct response to each item of concern in the 'Exhibit A" at the end of the study. The ' attached study, revised historic and developed drainage plans, and the revised grading plan do respond to comments and concerns presented by Stormwater Utility in the Project Comment Sheets from October 15, 1993 forward to this date. ' As both you and Basil are aware, our design team met with you in your 6ffices on July 25, 1994 and reviewed the revised grading plan (attached in the study), at which time our understanding was that the concept of the grading was conforming to and addressing the areas of your concerns. We are presenting the following Amendment Drainage Study to bring the project current and to meet current requirements of the City of Fort Collins. We are submitting two (2) bound copies of the Amendment Drainage Study for your review and approval. With the approval, we are also requesting that the Development Agreement be amended ' to release Lots 16 through 25, Block 1 for full development including the building permits. 1 �cl 3l� Recycled Mr. Glen Schlueter August 21, 1994 Page 2 During your review of the attached, if you have questions please call me and I can either answer them by telephone or meet with you at your office. Sincerely, JR EneineefFnk. Ltd. Richar� M. Kellogg, Jr., P Principal BRITTANY KNOLLS FILING NO. 1, PHASE 1 FINAL DRAINAGE STUDY AMENDMENT DRAINAGE STUDY TO KELLOGG ENGINEERING, INC. 1986 REPORT Prepared for: COLORADO LAND SOURCE, LTD. 8101 E. PRENTICE AVE., SUITE # M - 180 ENGLEWOOD, COLORADO 80111 AUGUST, 1994 Prepared by: JR ENGINEERING, LTD. 4812 S. COLLEGE AVENUE FORT COLLINS, COLORADO 80525 (303)282-4335 Job Number 9005.00 9 ' TABLE OF CONTENTS ' CERTIFICATIONS........................................................I Owner's Certification .............. 0 ......... ....................... 1 ' Engineer's Certification ................................................ i INTRODUCTION . 2 PROJECT LOCATION ..................................................... 2 ' METHODOLOGY ................. ........................•2 HISTORIC DRAINAGE ............................3 DEVELOPED DRAINAGE .................................................. 4 Sub -basin F ......................................................... Design Points H. I, andnd E. 4 Swale..............................................................4 ' Sub -basins A,B:C and D...............................................4 Design Point 3 . 5 Sub -basin E.........................................................5 ' CONCLUSIONS .:............................ ................ ....... ......5 EXISTING DRAINAGE PLAN HISTORIC ..................................... 6 FINAL DRAINAGE PLAN DEVELOPED ...................................... 7 ' GRADING PLAN .......... ............. ..... .... ....:..................... 8 EXHIBIT A...............................................................9 APPENDIX...............................................................13 ' HISTORIC DRAINAGE CALCULATION . . 14 DEVELOPED DRAINAGE CALCULATION ........ _ ........................ 20 PROJECT COMMENT SHEET ............................................. 30 1 ' 1 71 u L I I I 11 11 t J CERTIFICATIONS OWNERS CERTIFICATION Brittany Knolls Land L.L.C., A Colorado Limited Liability Company hereby certifies that the drainage facilities for the proposed Brittany Knolls Filing 1, Phase 1 subdivision shall be constructed according to the design presented in this report. I understand that the City of Fort Collins does not and will not assume liability for the drainage facilities designed and/or certified by my engineer. I understand that the City of Fort Collins reviews drainage plans pursuant to Colorado Revised Statutes Title 30, Article 28; but cannot, on behalf of Brittany Knolls L.L.C., A Colorado Limited Liability Company guarantee that final drainage design review will absolve the Coventry Subdivision and/or their successors and/or assigns of future liability for improper design. I further understand that approval of the Final Plat and/or Final Development Plan does not imply approval of my engineer's drainage design. Brittany Knolls Land L.L.C., A Colorado Limited Liability Company Mr. Jam Xory ENGINEER'S CERTIFICATION I hereby certify that this report for The Final Drainage Study for the Brittany Knolls Filing 1, Phase 1 subdivision was prepared by me or under my direct supervision in accordance with the provisions of the City of Fort Collins "STORM DRAINAGE DESIGN CRITERIA and CONSTRUCTION STANDARDS" for the owners thereof. I understand that the City of Fort Collins does not and will not assume liability for drainage facilities designed by others. RicharcyM. Kellogg, Jr., P:E. Colorado Professional Engineer o. 9265 For and On Behalf of JR Engineering, Ltd. 1 INTRODUCTION ' The Brittany Knolls Filing No. 1 subdivision was originally subdivided in 1986 by the Dale C. Bullough Co. At that time, Kellogg Engineering, Inc. prepared the original construction engineering documents for that subdivision. Additionally, Kellogg Engineering, Inc. prepared and had recorded ' the plat for all of the Brittany Knolls Subdivision. Subsequent to 1986, portions of the Brittany Knolls subdivision have been developed and necessary revisions to originally approved plans and ' studies have been made over the ensuing period of time. At this time, Block 1, Lots 1 through 25 and Block 2, Lots I through 16 (total of 41 lots) are in the process of being completed and residential homes constructed upon. ' The City of Fort Collins statutes and regulations require that any approved construction plans that have not been utilized within a one year period of the date of original approval are subject to currency requirements, including update of drainage studies and update of the construction plans. Additionally, state laws have been established in the interim period since 1986, requiring erosion and sedimentation control studies and construction plans. Erosion and sedimentation control studies and plans have previously been submitted and approved with respect to the above referenced 41 lots; however, the Stormwater Utility division of the City of Fort Collins has required that the developed drainage study and grading of the 41 lots be revisited and upgraded with respect to current trends and requirements. The following submitted data and documentation has been prepared to meet the current requirements, and is submitted herein as an addendum and supplement to the original Kellogg Engineering, Inc. drainage report of 1986 and not as a complete replacement of that report. Since October of 1993, ' the Stormwater Utility division of the City has provided "Project Comment Sheets" which have been significantly helpful in the preparation of the following responses. ' PROJECT LOCATION ' Brittany Knolls Filing No. 1 subdivision which incorporates Block 1, Lots 1 through 25 and Block 2, Lots 1 through 16 (a total of 41 lots) is located in the Southeast One -Quarter of Section 12, ' Township 6 North, Range 69 West of the Sixth Principal Meridian, City of Fort Collins, County of Larimer, State of Colorado. More specifically, the project lies north of Trilby Road, west of Brittany Street, east of the City of Fort Collins TransFort facility, and south of the existing developed portions ' of Brittany Knolls ' METHODOLOGY Brittany Knolls Filing No. 1 is an approximate 10.5 acre tract of undeveloped land. Since the area ' of this tract of land is less than 200 acres, the Rational Method is being utilized to evaluate both the Historic and Developed drainage patterns and flows. The developed flows will be evaluated to assure the City of Fort Collins, existing development, and future residents that no damage to private or public property will occur as a result of the development. It has been assumed in the following 1 2 calculations that the minimum times of concentration are 5 minutes for the initial 2-year storm and 10 minutes for the major 100-year storm. Additionally, the existing 5' Type R curb inlet located ' northeasterly of the intersection of Courteney Circle and Brittany Street, on the westerly side of Brittany Street, will be utilized to intercept street flows to the limits allowed for both the 2 and 100 . year events. HISTORIC DRAINAGE ' The original Kellogg Engineering, Inc. historic topographic mapping was prepared in 1986 prior to ' any site development. Since 1986, portions of the Brittany Knolls subdivision have been developed, and consequently the topographic nature of the remaining property which is the subject of this report has been somewhat altered. Therefore, the 1993 aerial mapping prepared by Geonix for the City of Fort Collins has been utilized for the current existing topographic mapping of the project site. The attached reduced drawing (11" x 17", approximate half scale) of the Historic Drainage Plan shows that the existing site is comprised of generally six sub -basins, identified as A through E and 0-1. The ' relevance of these sub -basins is basically to Sub -basins A and B which have historically drained offsite to the west onto the now City of Fort Collins TransFort Facility property. As the attached calculations show, the historic offsite flows towards the TransFort Facility at Design Point 2 (combined accumulated flows for Sub -basins A and B) are: , ' Q(2) = 1.53 cfs, and the Q(100) = 5.61 cfs The other significant issue is related to Sub -basin E which includes existing developed lots to the north and east of the current project site. The historic mapping (attached Historic Drainage Plan) indicates that Sub -basin E drains onto existing lots to the east of this project; however, actual on -site observation of the project site shows that the undeveloped property to the west of the developed lots has created its own drainage ditch which intercepts Sub -basin E overland flows and diverts them to Brittany Street and not onto the developed lots. Discharge of Sub -basin E drainage flows is to ' Brittany Street near the existing curb inlet and not onto the existing developed lots. Existing routed offsite flows are generated along Trilby Road with an initial point of concentration ' at the southwesterly corner of the subdivision, draining east as curb flow to Brittany Street, then along the westerly curb line of Brittany Street to Design Point 1. The west side of Brittany Street combines flows with the Trilby Road flows and Sub -basins C, D, and E at Design Point 1. The accumulated drainage flows for the historic drainage at Design Point 1 (existing curb inlet) are Q(2) = 5.27 cfs and Q(100) = 16.96 cfs with Times of Concentration of 14.8 minutes and 17.1 minutes respectively. 1 1 3 I F DEVELOPED DRAINAGE The proposed development has been divided into nine (9) sub -basins identified as Sub -basins A through I, and additionally includes off -site Sub -basins 0-1, 0-2, and 0-3 (which are generally tributary drainage from Trilby Road and Brittany Street). The concerns related to the developed flows relate to several significant areas, as follows: Sub -basin F - This sub -basin comprises the area which is offsite drainage flow towards the TransFort Facility in the developed condition (Sub -basins A and B on the Historic Drainage Plan). The following shows that the developed flows are less that the historic drainage flows, and therefore are not detrimental to the TransFort Facility due to the construction of the proposed development: Historic Q(2) = 1.53 cfs Q(100) = 5.61 cfs Developed Q(2) = 1.16 cfs Q(100) = 3.68 cfs Design Points H,1[, and E - These design points are the points of maximum discharge from rear lot swales in Sub -basins H, I, and E. The flows in these swales have been evaluated relative to the maximum 100-year drainage flows and also the 133 percent swale capacity flows have been evaluated. It has been demonstrated in the attached calculations and the proposed swale design shown on the Developed Drainage Plan, that the criteria of either 1 foot - freeboard or a capacity of 133 percent of the design flow can be accommodated in the designed swale. Additionally, a berm has been designed along the existing developed lots to the east of Sub -basin E which provides additional protection to the existing lots. We have limited as much as possible, cross lot drainage; however, it is impossible to eliminate cross lot drainage, totally. On the "Final Drainage Plan Developed" (attached as an I V x 17" approximate half -scale drawing) a "Typical Swale Section at Fence Crossing" has been detailed and shown. The swale section has been designed for the maximum depth of 6-inches; however, the actual maximum depth is 5-inches (0.42 feet) at Design Point E. ' Swale - The required grass -lined swale is a triangular swale 4 foot wide with a maximum depth of 6-inches at the center. This swale is to be used at all locations throughout the subdivision (not limited to Design Points H, I, and E). Sub -basins A. B, C. and D - These sub -basins drain to the front of the lots, and then travel by curb flow to their respect Design Points A, B, C, and D. The Sub -basin A, B, C, and D flows have then been accumulated with all other contributory Sub -basin flows from 0-1, 0-2, 0-3, G, H, and I to develop maximum flows at Design Points 1, 2, and 3. Design Points 1 (intersection of Brittany Street and Westbourne Circle), 2 (intersection of Brittany Street and Courteney Circle), and 3 (existing 5' Type R curb inlet) have been checked to verify that the 2-year maximum accumulated developed flows (3.73 cfs, 7.83 cfs, and 9.87 cfs, respectively) do not exceed the capacity of the curb flow of Brittany Street of approximately 12.5 cfs. 4 I I 0 l t 1 1 h Design Point 3 - At Design Point 3, the existing curb inlet accepts and pipes 5.92 cfs and 3.86 cfs for the 2-year and 100-year developed flows respectively (see calculations in Appendix). Bypass flow then becomes 3.95 cfs and 30.66 cfs respectively for the 2-year and 100-year developed flows. The capacities of Brittany Street for the 2-year and 100-year developed flows are approximately 12.5 cfs and 83.2 cfs. Both the 2-year and the 100-year developed bypass flows are well within the limits of the street capacity. Sub -basin E - Sub -basin E will discharge either the 2-year or 100-year developed flows of 0.51 cfs and 1.79 cfs directly to Brittany Street and will accumulate with the street bypass flows flowing to the northeast in the curb. Based on the above flows, the discharged flows will overland flow over the sidewalk and curb into the flowline of Brittany Street. CONCLUSIONS It is concluded that: 1?� The current developed drainage for the 2-year and 100-year events remains very close to the values of the original 1986 Kellogg Engineering, Inc. drainage report, 2. the revised grading plan has reduced significantly the impact of cross lot drainage, 3. required drainage swales of 4-foot width and a maximum 6-inch depth can be utilized throughout the subdivision, 4. the Brittany Street curb flow capacities for both the 2-year and 100-year developed events are not exceeded, 5. offsite flows towards existing development to the north and east have been eliminated, and 6. the offsite flows for both the 2-year and 100-year developed events discharging as sheet flow towards the TransFort Facility are less than the historic flows. Attached in the "Appendix" are supporting calculations and full size (24" x 36") prints of the Existing Drainage Plan I-Iistoric, Final Drainage Plan Developed, and the Grading Plan. The following reduced copies (11" x 17") of the above drawings are attached for reference during review of this report. (These reduced plans are not to scale). 5 I 1 I [l 1 1 EXISTING DRAINAGE PLAN HISTORIC BRITTANY KNOLLS FILING NO. 1 !A PORTION OF THE SOUTHEAST ONE -QUARTER OF SECTION 129 TOWNSHIP S HORTH9 RANGE 89 WEST OIL THE SIXTH PRINCIPAL MERIDIAN, CITY OF PORT COLLINS9 COUNTY OF LlAROMER9 STATE OF COLORlADO 11 1 _ 11 II ' \ / \ \\`\ \` \\\ \ 11 \\ \\\ \\ \ \\------- --_______ I II1111________- _ _ _ 1 1 IIII �_ \ ------------ I .9u------------------ ----- \ \ ------------- '_____ _ '�=_-=_-=- I - \ I , , \ \ \` \ -\ - - - --- ----- - ll\ \ \ \" _ -- - k A i y; �\ - 1 is --- /toy' av,rcnov — savv en4nwr ElACRIRAAtFD f19Y'GS90V PoN) lIt49W 4T.W/.Ii IiPP' W O. OYA9//RIAW AI AI \ - --------- \ 1 fF =87 1, \ -F- III, --- .__\__----'--- _ \-� _y/ ;' !I /` —�•`` • '; T-- - — —fP� �' \ 1 I ��� \ // -tT- II III _�� _ l -� —� i •►'/ / ` /~I , / l I \\ i _ ` �► ` 'sRs0j 1 III I — so as o so too i I 11 !___---_' / / _-_- / CA - _i % / SLEi l' = SO' r9as /------ ! DRAINAGE SUMMARY TABLE raw 1 11 I= ---- ; ' � i- - ; -/-' � ,- 1---- ------ ---- -I� ARE 0 0� 0 00 Tp( Tc (,00 [p C (79 'I III-'/ ------------- - - �` I ! : { �S -/ / ,-I POItIT Ela (AW&) x 1.09 ><1.28 LIN cMIR>' POFS3 (CFS4) II A A 1.55 0.20 0.20 0.25 11.8 10.1 0.73 2.75 fir 1 IIII 1.70 .2 0.20 .2 1.4 ,O.B 0. 294 I_ -� -�I I 11 ,�` " / If -�\ /'.--- -' ,� ,' I--` ' '' �9� r -_ III\:2 0.2 2 12, 1. .7 160.2 1 I I / I I r-'_`j^� ,'� I-1:23- O:H� \ 4. 6.2 18.9 BRITTANY STREET_ �_�. � / ' � � _ � ' `' --\ ! `�— -- — ` —/= � - �/ -C---_ � I\ ♦ __ ,' � �' - `\ --� \\�\\\ \ /'� \� �- _-_ - ____ _� �r� \ �,� �\\\ � �h\\ Vim` �/ � . 85 BRITTANY KNOLLS SUBDIVISION y� ',\\ 1 �1 \\ Lr �I\ \\ , T— / 10JEC9T4 N0. 8005.00 -14812 South Collee Avenue 1 \ i / I I R Fort Collins, Colorado 80525 �� 1 1 I I / V / 1Tel. (303) 282-4335 10 /\ \\ \ \ \ \ / / / / I FAX (303) 282-4340 1 ENGINEERING/PLANNING/SURVEYING 0 I 1 1 t 1 J 1 TYPICAL SWALE SECTION N n�1pIQAO TSECTION NOT SCALE (SEE NOTE) FINAL DRAINAGE PLAN DEVELOPED (� BRIITT� A�t,RNY KNOLLS R (�FILING F�NO, 1 ` �//MG[^�Q R.POf�1PlUCH gOpRF 1�PpHE SOM�piP�WLS�L/7iIST OBV�[�=�p�Bl,1MLiI[L����v'/16y�WILR OF �&IRl/�al�n1P/�0®a�/�12 /�M t 4®VA/IIVc�'D1O 8 NORTH, Wy RANGE 69 EST OI! THE SOX Il W IF'WII1VlvJI1�4i1tL- IANERIDILiH9 C OTY OF FORT Cc:OO LLOMn S9 COUNTY OF LAA, ROWER9 STATE TE OF COLORADO TYPICAL DISCHARGE SWALE DESIGN POINT Q ((1 r p (FPS)) (FT) H 1.17 1.97 0.385 1. 0. 9 1.80 5 420 ----------------- - \ \ I\ LEGEND R4SW L1[9OVA B C A GTY/Frfdr .IAlA N AOKS amp IOU sasw AWDR4PF lACa4"A4Wft NLY519v PoWr ----- Gii1hC NV/K1t NS1119 Q]'/"NXX PROA0 FG C N7" Aft Y Ownw ACYX !iF Ov GGNZMrl1ANW PAN 51.1 x AIGIVPOWradVAAW 50 25 0 50 100 SCALE, 1' a 50' DRAINAGE SUMMARY TABLE DESIGN POINT AREA DESIG AREA (ACRES) C C2 x 1.00 CIOO x 1.25 T< f�) (MI Te (f IOU) A (p) gCfS) (� 0(CFS�) A A 2.19 0.45 0.45 0.56 12.9 12.9 2.23 7.90 1.1 0. 9.1 -10.6 1.32 4. 1 E 0. .4 - 0. 11.9 11. -0 5-7 7. F 0.92 -0. 1 1.1 .6 H H 0.2 .45 11.6 10.0 0.31 fi I .4 10.1 1 0.51 1. -3 - 5 1.W 0.24 1 0-1 + A 3.18 12.0 12.9 3.73 13.21 2 0-1 + A + B + C + 0 + H + I + 0-2 7.62 15.6 15.5 7.93 27.46 3 0-1 + A + B + C + 0 + E + G + H + I + 0-2 + 0-3 10.88 16.4 16.4 9.87 3.4.52 NOTE: WHERE 'TYPICAL SWALE SECTION' ARE RE- WIRED, ALL LOT OWNERS MUST MAINTAIN SWALE SECTION TO INSURE THAT NO BLOCKAGE WILL OCCUR. NOTE: LOTS SHALL BE SEEDED, AND SILT FENCE SMALL REMAIN IN PLACE AROUND NEWLY BUILT AREAS, UNTIL ALL LANDSCAPING IS INSTALLED IN NEWLY BUILT LOTS, I BRITTANY KNOLLS SUBDIVISION PROJECT NO. 9005.00 8/15/94 JREngineering, Ltd. 4012 South College Avenue Fort Collins, Colorado 80525 Tel. 303) 262-4335 FAX 303) 282-4340 ENGINEERING/PLANNING/SURVEYING VARIESPAPIEVARIES O 07 RowOwfcnov4VAME� O 1.SA (2A MIN.)ED GRADEIN,) f1MI5NE0 GRACE �- LVSIAG G17V)LYR ARQ' SO 23 0 SO 100 ERLpi GRADE OVERLOi GRADE ' TMIC/1 I� TVDICAL 'B' LOT I ,�•A "IrAL� WALK OUr LOT SCALE, ,' • 50' ® [or /HC45.00 �` y Musnw 41NA I!)CW ® mwwnov[or coS^�16 -___-- - -T■ -______ 53.6 X AWi/s��r e[fVAITQV cow p 4B4p \ \ ---- ------ ------ 4950 +ass I / 1 __ _ \ \ \ \ 4950 _____-\..�--_'_-� _ _—�_ �_ .a ip o5"a•`� 23 Nm 315 2'6rs TDF / 1 \ � 70I• S3. ____ _ :� \uA\ S3i\ ° ,.41 1 O I III 52.3 1 fF M87 ! / TOF- — ' 'WE—TBOURN_EIftC I 17, / 70pp // B 14 75i0 5't2 SFF. u 4.9 / 1 111 TGIF. ,l O / / \I / / ' TOF. \ i / I i / / \ 1 1 I 53.2 ->r _ �' / / / 13 ® 52.8 / I 1 III i '''2.0.i/ 51.2 ® GENERAL1. STREET ELEVATIONS SHOWN ON THIS DRAWING ARE APPROXIMATE \ �/ / > ; FINISHED GRADE. SEE STREET PUN AND PROFILE DRAWINGS 52.7 �� _ 18 5tl - _ 1 // l� / OR EXACT STREET GRADES. _ _ CFF 3283 / `S1.S ,P � 2. ALL AREAS SUBJECT TO GRADING OPERATIONS SHALL BE LET TGIF. 1$ so -tw SEEDED H SOON AFTER GRADING OPERATIONS ARE COMPLETE TGIF. I - 544 _ _ - / j _ 51S_� / AS WEATHER ALLOWS, OUT NOT TO EXCEED SIX WEEKS N7TNWT p \ / INTERIM MEASURES SATISFACTORY TO THE CITY OF FORT COWNS. 50.0 -®"' _ / / 12' - RESEEDING SHALL CONSIST OF A MIXTURE OF 35% SLENDER WHEATGRASS, 25% STREAMBANK WHEATORASS, 20% SMOOTH \ \ BROME AND 207 INTERMEDIATE WHEATGRASS APPLIED AT A RATE 4-� 3 3 - _ Q 7pF. \ !-\ \ lS -f /^I OF 30 LBS. PLUS PER ACRE FOLLOWED BY CRIMPED MULCH / _ TGIF- TGIF �49.6 APPLIED AT A RATE OF 2000 LBS, PER ACRE. ALL CHANNELS 54.5 482 18 \ U I /p-�/ AND DRAINAGE SWALES SHALL RECEIVE EXCELSIOR MATTING. /! \_I\\ 11 11\\ \ \ \\ �yj j- 2 TGIF• y D T'J4:J\'T I / l // 3. GRADE LINES SHOWN ON THIS DRAWING INDICATE APPROXIMATE FINISHED GRADE FOR LOTS AND TOP OF ASPHALT OR TOP OF CONCRETE FOR CURBS AND SIDEWALKS. ®0F• 1 r----�� // 4. PROPOSED SPOT GRADES SHOWN ALONG BRITTANY STREET AND i 7OF- 1 1 _ \ \ / / Qj 3• __ 1R LE 4 1 / I EXISTING SPOT GRADES SHOWN ALONG THE BACK OF LOTS 4g rp y 16-25, BLOCK 1 ARE APPROXIMATE ONLY. FINISHED GRADES - _ _ Tp'•- \ i__5Jl /I MUST MATCH EXISTING, AS -CONSTRUCTED GRADES. gi m 3 3 T r- 1 / _7 s 6 45. u•8 ` �' ® '� / 5. ALL EMBANKMENT COMPACTION SHALL MEET OR EXCEED DENSITY 0 \ r E2 AS STATED IN THE APPROVED SOILS REPORT FOR PROJECT, AND MUST MEET ALL FHA MINIMUM COMPACTION O REQUIREMENTS. y y y , F FF 48131 / I 6. BENCHMARK: � < `I 1 \ SPIKE IN POWER POLE. 34Y NORTH OF THE OF THE N E QUARTER OF SECTION S, TSN, R69W.• CORNER ���777fff m 0 m - 1_ _ _ �4 \ / 11/ 1 ELEVATION . 4281,33 _ I / ~ •8 J _ \ _`\-\//� / \ 7. WHERE TYPICAL SECTION SCALE' ARE REQUIRED, ALL LOT BRITt'ANY I / _�� _ 'i / TGIF _ \ / � ^\\ OWNERS MUST MAINTAIN SCALE SECTION TO INSURE � /\/ THAT NO BLOCKAGE WILL OCCUR. J \^ NOTE: (J \ \ \-�' '' '' -\r `h• /� - _ - -- - __-__- �^ \ !y \ / THIS SHEET REPLACES SHEET 5 OF 24 OF THE -\ \ l / .� - \ AAA / TGIF• _ . _ -\\ \ \ �9 \' Z. ORIGINAL BRITTANY KNOLLS FILING NO. 1. PHASE 1 UTILITY PLANS BY KELLOGG ENGINEERING, INC., ¢ O DATED 10/88. (L M O 'L7 0 City of Fart Collins, Colorado z z z L-r 1 1 - \ UTILITY PLAN APPROVAL Y Q e rsra� 3 ?Xp� k\ \\ f �' �✓ �� 1\ L` APPROVED: J 4' /�cA 4N�t\�\ .� �- ^\\\-' \- `.\ _ \ \ \.c \ `- Fonr cOlun- uon..nu 0m z L7 O souTH Faler caumssrwuil0�x IX ip m Q O \ \ \\•�•\\ \\/\ -\`G• \ N. \� \ CHECKED BY: Q �! \ \ UTILITY PLAN APPROVAL waev AwwM.e,r uany I,aM 0.5' \ \ CHECKED BY-.-,..m 0.5' l \ \\ \ �- \ I \ 1 I ,11 / 1 I APPROVED wmy O 4' \\ \ \ \ \ IRJO YANA9NR IJ DATE CHECKED BY:� TYPICAL SWALE SECTION APPROVED CHECKED BY: SHEET 5 OF'24 AT FENCE CROSSING +A TYPICAL SWALE SECTION A/ mrzuswaNEla o.a NOT TO SCALE " NOT TO SCALE °A� CHECKED BY: JOB N0. REV. (SEE NOTE 7 SEE NOTE 7 �� 9005.00 I 1 1 "EXHIBIT A" The following remarks are in direct response to the "redlined" print (attached, and being returned as requested) and the "Project Comment Sheet" dated July 9, 1994 and signed by Mr. Basil Harridan of the Stormwater Utility department. As you will note, on the redlined print, we have numbered the City's comments sequentially in order to respond to the areas of concern. Additionally, we have continued the numbering sequence on the Project Comment Sheet, similarly to respond to each area of concern presented. 1. The flows for the Developed Area F are as follows: HISTORIC CONDITIONS: Q(2) = 1.53 cfs Q(100) = 5.61 cfs DEVELOPED CONDPITONS: Q(2) = 1.16 cfs Q(100) = 3.68 cfs As you can see, the developed flows are less than historic. There are no point discharges associated with these lots since all lots will be discharging by overland flow (as historic) to the offsite area (TransFort). 2. Items 2, 4, and 16 all relate to swales. Swale design is included within the most recent drainage calculations for developed flows. Not only in these specific locations but wherever else swales are required, they all will be triangular grass swales, four (4) foot wide, and have a depth of six (6) inches maximum at the center. Swale sections have been shown on both the current "Developed Drainage Plan" and the "Grading Plan". 3. There is a 'IfEgh Point (HP)" located at the end of the cul-de-sac in the flowline, and this has been reflected along with the Elevation on both the Developed Drainage Plan and the Grading Plan. 4. See Item 2., above. 5. There is no phasing associated with this project. 6. Existing and proposed contours have been shown as requested on the historic and developed drainage plans and on the grading plan. The existing contours have been taken from the City of Fort Collins aerial maps which were produced in 1993 by Geonix. The contours shown are significantly more current than the original topography and match the field shots of the lots along the northerly boundary of the subdivision. 7. Existing contours have been extended offsite, even though there is not expected to be off -site ' flow with the exception of Sub -basin F. 0 ' "Exhibit All 8. Subsequent to the redlined print review, the erosion and sedimentation control report and construction plan has been approved by Stormwater Utility, and is not required at this time. 9. See Item 8, above. 10. Cross sections of swales have been shown at the significant locations. All other swales shall be the same as the significant locations. See Item 2., above. 11. The "Developed Drainage Plan" and "Grading Plan" do not allow any concentrated flows onto offsite existing development or lots. 12. Finished lot foundation elevations have been shown on the plans. 13. It is not possible to eliminate entirely concentrated flows discharging to adjacent lots. However, during a meeting with both Glen Schlueter and Basil Hamdan on July 25, 1994 it was demonstrated that significant changes have been made to the grading plan to reduce and/or eliminate cross lot drainage. Additionally, the swales shown on the "Developed Drainage Plan" and the "Grading Plan", which are located at the point of maximum discharge, do not have significant 100-year discharges. The highest discharge is 1.82 cfs, which is controlled easily with the swale design described in Item 2., above. 14. Drainage "Summary Tables" have been shown on both the Historic and Developed Drainage Plans. , 15. See Item 8, above. ■ 16. See Item 2., above. ' 17. Addition of the design point is unwarranted with respect to the revised grading plan. The grading plan as revised, redirects the flow to the proposed Swale which starts at the easterly ' corner of Lot 21 and follows the rear lot property line through Lots 22 through 25 and discharges to Brittany Street at Design Point 3. ' 18. Existing lot lines have been shown, existing elevations at the comers of the proposed lots have been shown, and foundation elevations of the existing and proposed lots have been shown. 19. In the title block, the word "Erosion" has been changed as appropriate to "Developed" or "Historic". ' 20. We understand that the 1986 approved drainage and grading plans have expired. 10 I "Exhibit A" ' 21. In accordance with Stormwater Utility's request we have updated the grading and drainage plans. The erosion control plan has previously been submitted and approved as part of the ' Development Agreement. The revisions ensure that no harm is done to future and current homeowners in the Brittany Knolls Filing 1 area. 22. Existing contours have been shown on the adjacent existing lots. These contours are based on the 1993 City of Fort Collins aerial mapping prepared by Geonix. Additionally, finished top of foundation elevations and back lot corner elevations have been field surveyed by 7R ' Engineering, Ltd. and are shown on the plans. These elevations correlate with the Geonix aerial mapping. (See Item 18., above). ' 23. Easements have been prepared for all lots in the subdivision to include side lot and rear lot easements for drainage purposes. These easements will be 5 feet wide on the side of the lot ' and 7.5 feet on the rear lot line. The easements will be recorded with Larimer County by the current Owner of the property. As discussed earlier, the cross lot drainage is limited to the proposed subdivision and has been minimized by the revised grading plan. This grading plan ' has been discussed with Stormwater Utility, and the concept generally approved with appropriate details. There is no drainage discharge onto existing lots to the north of this subdivision. ' 24. The revised grading plan shows the high point elevations, direction of flow, lot corner elevations, and relationship with offsite development. Additionally, the grading plan shows ' schematically the different types of lots, e.g. Type A, Type B, Type W, and Type T. These schematics show the basic grading and direction of flow on these types of lots. ' 25. See Item 18., above. ' 26. See Items 7., 12., 18., and 22., above. These elevations are not remaining the same due to revisions of the grading plan. There are no concentrated discharges from the site onto existing developed lots, or otherwise. 27. The notes will be added to the grading plan; however, the erosion control plan has previously. been submitted and approved as discussed above. ' 28. Items 1 through 19 above address the redlined plans. ' The following comments are related to redlined prints received by our office on Tuesday, August 9, 1994. These redlines are identified with roman numeral delineation for comment herein. ' 11 I ' "Exhibit A" ' I. Ref. Sheet 5 of 24, entitled "Grading Plan", most current revision 4/94 - Retaining walls are not required. The Grading Plan has been revised and was reviewed in a meeting with Stormwater Utility (Glen Schlueter and Basil Harridan) on Tuesday, July 25, 1994. General ' consensus was that the revised grading plan would work and would be reviewed at the time of the submittal of the drainage study amendment to the original 1986 Kellogg Engineering, Inc. study. The revised grading plan has incorporated Type A and Type B, FHA lots which drain to the street or to a designed swale at the rear lot line. Additionally, the side slopes into the side lot drainage swales are maintained at a minimum of 4 (horizontal) to 1 (vertical), which is easily managed with landscaping and is not an unreasonable slope. ' II. Ref. Sheet 5 of 24, entitled Grading Plan", most current revision 4/94 - The proposed ' retaining wall shown on this drawing influences two lots, Lot 9 and Lot 10 of Block 2. The revised grading plan (copy attached to this amendment) has limited the retaining wall to only Lot 10, Block 2. The issue of "who builds the wall" and "what type and detail" was discussed on August 16, 1994 with Stormwater Utility (Basil Hamdan) and JR Engineering, Ltd. (Dick Kellogg). Based on this discussion: • The overlot grading operation to prepare the lots for a builder will only grade the sideslope (no retaining wall to be built at this stage), • the home builder will be responsible for the construction of the wall, ' the type of wall and its detail will be the responsibility of the home builder or the prospective home buyers (neither JR Engineering, Ltd. nor the City of Fort Collins should dictate the wall type), ' Stormwater Utility will incorporate into the Final Development Agreement Amendment the constraint to Lot 10, Block 2 which will require addressing the wall detail and construction by the home builder at the time of building permit, and ' no detailing or type selection is required by JR Engineering, Ltd. for the approval of the grading plan as revised and submitted herein. _ ' III. Ref. Sheet 5 of 24, entitled "Grading Plan", most current revision 4/94 - Further discussion on August 16, 1994 with Stormwater Utility (Basil Hamdan) determined that additional notes ' related to Lots 1-14, Block 2 and also the "GENERAL NOTE" would not be added to the current drawing. With the approval of the attached "Grading Plan", all of these lots; and additionally, Lots 16-25, Block 1 will be released for total infrastructure construction. ' IV. Ref. Sheet 1 of 24, entitled "Cover " - The request for an additional note concerning Block 2 is not required. See comments in Item III., above. [IPA 1 APPENDIX e 1 1 1 , ' 13 1 0 HISTORIC DRAINAGE CALCULATION 14 q m V) ' m N M N m v O U 0 U 0 a w N O h m ap O •- aD Q tVN�MC6IR m v> N �A Q V G C O N w O r- � � �- r• r. ,r O N N N N N O c Q:rK. 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(303) 282-4335 4812 South College Avenue, Fort Collins, CO 60525 PROJECT: Brittany Knolls PROJECT NO.: 9005M LOCATION: Bacidot Swale Design Point H Concrete NO Grass YES Grouted Riprap NO Swale calculation for triangular V channel Q S W D AREA WET. PER. HYD. RAD. n 1.16 2.02% 4.00 0.500 1.00 4.12 0.24 0.035 Q= 1.488/n"a2/3'S"1/2)= 2.35 CFS CAPACITY V= Q/A 2.35 FPS SET 9M TO BE A FUNCTION OF "D"/(must Set ratio of slope in W calc.) Q S W D AREA WET.. PER. HYD. RAD. n 1.16 2.02% 3.07 0.384 0.59 3.17 0.19 0.035 Q= 1.488/n(A'R;M*S"1/2)= 1.16 CFS ACTUAL Q V= Q/A 1.97 FPS Q(133%) S W D AREA WET. PER. HYD. RAD. n. 1.54 2.02% 3.42 0.427 0.73 3.52 0.21 0.035 Q(133%) 1.486/n(A-R"2/3'S^1 /2)= 1.54 CFS 133% OF ACTUAL Q= 1.16 V= Q/A 2.11 FPS x=o5W0 OPW%SWALES.WB1,08/27/94,11:47:31 I aq 1 1 1 1 JR Engineering, Ltd. (303) 282-4335 4812 South College Avenue; Fort Collins, CO 80525 PROJECT: Brittany Knolls PROJECT NO.: 900500 LOCATION: Ballot Swale Design Point I Concrete NO Grass YES Grouted Riprap NO Swale calculation for triangular "v" channel Q S W D AREA WET. PER. HYD. RAD. n 1.80 6.15% 4.00 0.500 1.00 4.12 0.24 0.035 Q= 1.486/n(A'R"2/3'S^1/2)= 4.10 CFS CAPACITY V= Q/A 4.10 FPS SET "W" TO BE A FUNCTION OF "D"/(must set ratio of slope in W calc.) Q S W D AREA WET. PER. HYD. RAD. n 1.80 6.15% 2.04 0.367 0.54 3.03 0.18 0.035 Q= 1.488/n(A"RA2/3"S"1/Z)= 1.80 CFS ACTUAL Q V= Q/A 3.33 FPS Q(133%) S W D AREA WET. PER. HYD. RAD. n 2-39 6.15% 3.27 0.409 0.67 3.37 0.20 0.035 0(133%) 1.486/n(A"R"2/3'S^1/2)= 2.39 CFS 133% OF ACTUAL Q' 1.80 V= Q/A 3.68 FPS X:\900500\QPW\SWALES.WB7 ,08/27/94,11:49:33 18 JR Engineering, Ltd. (303) 282-4335 4812 South College Avenue, Fort Collins, CO 80625 PROJECT: Brittany Knolls PROJECT NO.: 900500 LOCATION: BacMot Swale Design Point E Concrete NO Grass YES Grouted Riprap NO G Swale calculation for triangular V channel Q S W D AREA WET. PER. HYD. RAD- n 1.79 3.00% 4.00 0.500 1.00 4.12 0.24 0.035 Q= 1.488/n(A*RA2/3"S^1l2)= 2.86 CFS CAPACITY V= Q/A 2.86 FPS SET "W" TO BE A FUNCTION OF "137(must set ratio of slope in W calc.) Q S W D AREA WET, PER. HYD. RAD. n 1.79 3.00% 3.35 0.419 0.70 3.46 0.20 0.035 Q= 1.486/n( A7J3"S"1/2)= 1.79 CFS ACTUAL Q V= Q/A 2.54 FPS Q(133%) S 'W D AREA WET. PER. HYD. RAD. n 2.38 3.00% 3.74 0.467 0.87 3.85 0-23 0.035 0(133%) 1.486/n(A"R"2/3"S"1/2)= 2-38 CFS 133% OF ACTUAL Q=1.79 V= Q/A 2.73 FPS X:W005W0 QPW%SWALES.WB1,08/27/94,11:50:38 M ' PROJECT COMMENT SHEET 1 1 1 30 ' r PROJECT �, a � COMMENT SBEET ' DATE: 8 March 1994 DEPARTMENT: vwwekk- PROJECT: BRiTTANY Ili oLLs _ Fling 1 Phase 1 ' RECEIVED PLANNER: Kerrie Ashbeek JUL . 8 THIS PREVIOUSLY SUBMITTED,,NEEDS ' TO BE REVIEWED FOR CURRENT VALIDITY. Please respond to this project by. Friday March 1891"40 ' []No Problems "pis rev r j (#&bf t coements and ' to-,ur response we received comments that were submitted to the stormwat er ' oity on July 18t 1994. indicated earlier the previously approved drainage and grading Plans for the Brittany Knolls 1 *6nq have expired. �; a Stormwater Utility feels updated grading, drainage ��TT erosion controi�plan i essential in order to ensure that no is done to future current, homeowners in the Brittany Itnolls 1st Filing area. please existing contours and finished floor elevations on the neighboring existing lots and tie these into proposed contours on this phase of Brittany Rnolls Filing 1. ' Pleaso refer to the redlined basin plan for additional details t Headed on the grading and drainage plan. Oux main concern as was indicated earlier is that drainage not be directed from upstream lots onto existing or proposed lots. Cross lot drainage should be prevented whenever possible, if not pir Date: �/i' �- Si . ' CHECK YF YOU WISH TO RECErVE PLAN COPIES OF REVISIONS: L3 srrE t 0 LANDSCAPE' UTI zff ' COMA4UMI" PLANMc a PtitRO nt SYRV[CFS 2d1 No1rr8 COLLEGE i o 80C 580 POR2 COid P� tS, COLORApO �OS� f u21�� YI.A N1VT.Yr-P_ 1%7V heD A trrUsvr 3 1 ' then an easement would be re red Prom downstream to pass flows through these. lease give a typical ' for each type of lot that would be built so that bu know how the drainage is supposed to work on their (Back to front, grade break at the houses etc...)., corner ele ti in order image plan rs would icula�r lot va ons of each lot on the ale show ' finished floor elevations. grading plan as well as [� lease add details to the grading and drainage plan showing what [•� the proposed contours on the lots that are to be built are compared to existing corner lot lines and finished floor elevations in the already built portion of the site. Are these ' going -to remain as they were on the original plan ? If so, it is our position that 5pots ading needs to be changed in order to avoid having concentrows discharging onto neighbouring downstream property ownsease add notes to the drainage and ' erosion plan indicating will be seeded and silt fence will be kept around the newly built areas (especially in those lots adjacent.to. existing homes, until ALL landscaping is ' installedinnewly built lots. . 2P ease address the comments that were rediined on the plan that s submitted showing basin delineations. Please be advised that we will work with you in order to most your July 18 overlot grading start date, but soma restrictions may be imposed on portions of the site until all grading and ' utility plans are approved. This process can be.extended if we any additional are found at a later date so do not consider these as the only and final ones on this project. 3a c a yS9 M d EXISTING DRAINAGE PLAN HISTORIC BRITTANY KNOLLS FILING NO. 1 A PORToOOM OF THE SOUTHEAST Oafs=QUARTER OF SCCTOOM 5129 TWWHSHOP 6 MORTH9 MMC 89 WEST OIL THE BONTH PROMC OPAL PAERomug COTY OF FORT COWN89 COUNTY OF dARO ER9 STATE OF COOLOoRADO /��� _ I _ ♦ y � I„I Aa-_ r I' ilk II v _�,,;�lvvv�' %�����` -------„'I��' - . -_--_ - - --- - 1,70 Js 1.5so.z --------- II 'ilk 95 0.2 1� 000 -- �_ ef \/x IsI� 1 � I — — — uw ewA.oAnr o 11(6 [OWEI/MAMI/YAd 50 25 0 50 100 t- �Ero0mw®MEME�� ss® 111011M�®® a�aisa�ufa� MEAM MIUM - -- BRITTANY STREET-r--��-� \ K \- e 'ev \ 1 I I / I I BRITTANY KNOLLS SUBDIVISION PROJECT NO. 9005.00 8/15/94 JREngineering, Ltd. 012 South CoUge Avenue Port Cee v, Colorado 80525 ra. (aril 2U-4335 F" 202 282-430 NNGDWE G/PLANNMG/SURVEYSIG 3 T ICAL SWALE SECTION i I I 7 .45 FINAL DRAINAGE PLAN DEVELOPED BRITTANY KNOLLS FILING NO. 1 A PORTOOM OI: THE BOU'rHEA34 OME=OMAf TER OF SEC TOOM 12, SPOI�/A HSHEP 8 MOG9T TH9 RANGE (59 WEST OIL THE SOXTH PROMC MK WEROMM9 C MY OF FORT COLLOM89 COUNTY UNTY OIL dAMMER, STL%7E OF COLOO RADO 56 t�F SPIN Rk ak 1 El 63 I 1 us i sai.s N `. BRMANy STREET C 1- .26 .95 Lure MI TYPICAL (DOIpSCHAR(G�OEp SWALE PEgNi' 0(fi5)' YIFPSII IE» .�., 'Y H 0.385 _ A TYPICAL SWALE SEcnON 'A ,08 .95 NOT TO SCALE (SEE NOTE) 13 EN pDRq GNr A RAsWOOMM W 8 C RYpVY CMEAMN/ ARU M ACRES ROM 01WVMYI MOUNI OAIXtYpARD ROM[CR'N /CWr _ FJ smc CLW)q/R. EVS7Wc cav IX MttY —' MaY1VD LW]IXW PNNIID MV1pN M �� leF 0f 41]N9/M/MNM]/: 51.1 % Raw iWr EU:W %v 7 ps—sz('e] t �/ _ w,77 1.78 - �. 17, .45 - - TOE -TO'. 5 S SAI9J I s3.a Y4 I 52.0}2' S TOE- 520 13. 51.2 / v 18 f 52] .45 .4S 1.5 TOF- �. M.m / lili! I)/1 /IMail FIR FAA WWI 50 25 0 90 100 SCALES V - 50' g vvE�J�d:7�E:��.Ib.�F3i.iYi,lS1• ����t'6.7tbS�td1'7th' 1'>ifl3" f61M a OEM=�tEJtdI�tE3/Immmm*dfmumm iaY �td'F7♦td'ka=9:m1&XmmL1!mK& Lsomm �ra��a�a'��ara�u'>•�:�Ea�>.ira�ixcfca'z. s9"m E NOTE WHERE "TYPICAL SWALE SECTIONmARE RE- i OUIRED, ALL LOT OWNERS MUST MAINTAIN ' \� a SWALE SECTION TO INSURE THAT NO \f 1 BLOCKAGE WILL OCCUR. I 1 I 1 1 �\ 1 i NOTE: --' / / , LOTS SHALL BEA SEEDED, AND alli BUILT SHALL REMAIN IN PLACE AROUND NEWLY BUILT AREAS iiAAAA�✓///// UNTIL UILT ALL LANDSCAPING 15 INSTALLED IN NEWLY 1 BUILT LOTS BRITTANY KNOLLS SUBDIVISION PROJECT NO. 9005.00 8/15/94 Engineering, Ltd. JR 4812 South College AYevue Port Collius, Colorado 60626 Ssl. (303) 281 TAIL (303) 282-4340 ENGI4EERDH3/PLANNQ.`G/SURVEYING N J I I vq� eo GRAPHIC SCALE ( W RT /Jj•Cl �yy_ c.1.;o-i'c .�bv..Y� ... {Q.>.�-+1.� �' °� g� O � 3 � �Y§� NOe6 yn�e.:.9.Q y. �-� a2eas ,a4 rs. rt.I c; F� �I•.� �80NifA0y�� Sy�.u�4/�a�rYl NSn L E0 EN0 S. a(1 l.ctAJ 93 Flew a 1 VARIES E VARIES O ,.Ss mm"HOD GAME r IZX MI 44 OWAI9T WADE /1 TYPICAL 'A' LOT I a. I O � ; lIi< . O N� ri MSOI -� VARIES O OS nwsND aM �(2XYN) OY OT WADE rH\ TYPCAI 'B� InT `\ 13RITTANY -1 TYPICAL SWALE SECTION AT FENCE CROSSING NOT TO SCALE XVMIESGE TYP CAL �W 111(-OILY LCr �e�eee S�E 50 25 0 50 IN SCALE, V = 50' 4950 FT =8> LEGEND 2GIpML --�_..� mFAM tvmnnwRP -" -� a16me [xWraw Wm' �� ARaPMsa mvTour ��� nrma+eo mvraw evax ® LOT FIVE MVRWD LiLl41d/ AA00 ORION; 011WROW ® SM9AM'Lor 53.6X ILM;/a'FEIn,I>.w . o 5 � age M E$ � 0 3 �OaB NAaKgn� b0ltOggNgggi coin h��� � e v yo a em q eUI WIN N OWN tY 11 ot �IT R"52,; . FF=Saa9 3 ® szB GENERAL NOTES Q 51.2 ® y 1. STREET ASHOW ON THIS DRAWING E APPROXIMATE U - 18 51't _ / FINISHED GRADE. SEE GRADES. PLAN AND PROFILE DRAWINGS RXACTRDE. WN 5195 / 5 ( 51.5 15 u T�= - 2. ALL AREAS SOON A M GRADING OPERATORSOPERATIONS SHALL BE RE - AS EO AS SOON WFTER GRADING OPERATIONS ME COMPLETETHOU F5 IN WEATHER ALLOWBUT NOT TO THE SIX WEEKS WTHOUT INTERIM MEASURES SATISFACTORY OF TO THE CITY OF FORT SLE COLLINS. R /J 12 p� ® (" - _ ♦9:5. ./ RE -SEEDING SHALL TREAMB OF A MATURE S. 0X RENDER rc WNEATGAND X I INTERMEDIATE WHEATGRASS. SOl D AT TH BROME AND 20R INTERMEDIATE MOWED ASS APPLIED AT A RAZE / 5}i —�' TOF AP U AT PLUS PER ACRE FOLLOWED ED ACRE. CRIMPED MULCH TOF- '4 A- - �p.R FF�S1.J5 , APPLIED AT A RAZE aF SHOO LRE PERXCELALL ATTICHANNELS 54.5 4&4 16 \ AND DRAINAGE SWALES SHALL RECEIVE E%CFISGV MATTNH. lie ® 4 .W _ / 3. GRACE UNES SHOWN ON THIS DRAWING INDICATE APPROXIMATE FINISHED GRADE FOR LOTS AND TOP OF ASPHALT OR TOP OF CONCRETE FDA CURBS AND SIDEWALKS. - 53. 4. PROPOSED SPOT GRACES SHOWN ALONG BRITTANY STREET AND �fF I811 I - EXISTING SPOT GRACES SHOW ALONG THE SAM OF LOTS 1855. BLOCK CARE APPROXIMATE ONLY. FINISHED GRADES o m MUST MATCH EMSTNG AS -CONSTRUCTED GRADES. b K�j 3 Y 3 21 5. ALL EMBANKMENT COMPACTOR SHALL MEET OR EXCEED DENSTY �I m It 4 �F - I �. AS STATED IN THE APPROVED SCHS REPORT FOR PROJECT. AND O a)J �'/' _ MUST WEE ALL FHA MINIMUM COMPACTION REQUIREMENTS. m m m 23 FF=1625' e. BENCHMARK: i 494 _ Ta I SPIKE IN POWER POLE. 30' NORTH OF 1N.W. CORNER OF a o i N.E. QUARTER OF SECTION 13, MIN.. RBBW. 6-E ELEVATON 4981.33 94Hj p _2 ) WHERE "TYPICAL SWALE SECTION" ARE REQUIRED, ALL LOT OWNERS MUST MAINTAIN SWALE SECTION TO INSURE J THAT NO BLOCKAGE WILL OCCUR. ZS NOTZTHISSHEETREPPLCESSHEES OF 24 OF NSORIONAL BRI LING NO. 1, PHASE 1 DUTILITY ATED ID PLAINS BY KELLOGG ENGNEERINC, INC., ZQ O r�l CRy of Fart CGNIME, COIMOCo Z H O UTILITY PLAN APPROVAL Y ¢ g APPROVED: } K FORT CRISIS - LOWIM) WArtx DT I».nw a nyn..ny IIw Z O \ \ 1\\ \\ AMTAnPI RUN FORT MILKS SDISTRICT Q Q \\\\\ \ — \ \ ✓`\ S A CHECKED BY. Q UTILITY PLAN APPROVAL wN. A nH..aI. ININY CHECKED BY: m I APPROVED 'Slwm.n. MAY DN. Q ANN I / / MANAGER I Q / / DALE CHECKED BY: Per ItReslbn DOM APPROVED CHECKED BY: wM SHEET 5 OF 24 sums waIIMR DAME CHECKED BY: JOB FRO