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Home My WebLink AboutSUBDIVISION PRELIMINARY - QUAIL HOLLOW - 46-89B - SUBMITTAL DOCUMENTS - ROUND 1 - DRAINAGE REPORTOctober, 1989 • Preliminary Drainage Report for Quail Hollow P.U.D., Filings 4 thru 7 7r '# '4 .f 1 0 lJ PRELIMINARY STORM DRAINAGE REPORT FOR QUAIL HOLLOW P.U.D. FILINGS 4 THRU 7 PREPARED FOR d. JENSEN ENTERPRISES INC. P.O. BOX 1007 FORT COLLINS, COLORADO PREPARED BY RBD, INC. ENGINEERING CONSULTANTS 2900 SOUTH COLLEGE AVENUE FORT COLLINS, COLORADO 80535 (303)226-4955 • INDEX Introduction Location Purpose Existing Description Proposed Description Procedure Design Criteria Offsite Drainage Onsite Drainage Conclusion and Recommendations References • Page 1 1 1 3 4 Appendix "A" Vicinity and Offsite Basin Map Pipe and Pond Sizing 2 Year and 100 Year Historical and Developed Storm Discharge Cal- culations INTRODUCTION 0 � I I Location Quail Hollow P.U.D., Filings 4 thru 7; as shown in Appendix "A", is a parcel of land with approximately 60 acres planned for residential development and a site comprising approximately 20 acres to be developed by the City of Fort Collins as a park. The northern boundary of the site is located 1/4 mile South of Drake Road and the southern boundary lies 1/2 mile South of Drake Road. Filings 4 thru 6 lie east of; and Filing 7 lies west of the southerly extension of Overland Trail. More specifically this P.U.D. is located in the south half of the Northwest 1/4 of Sec- tion 28, Township 7 North, Range 69 West of the 6th Principal Meridian in Fort Collins, Colorado. Purpose The purpose of this report is to create an organized plan for fu- ture development within the P.U.D. This report will address passing the discharge from the 2-year and 100-year design storm through the site assuring safety of life and property. Existinq Condition The site can best be described by two parcels; divided by the southerly extension of Overland Trail. The site west of Overland Trail (7th Filing) is vegetated with natural Colorado grasses and slopes generally easterly at grades around 7% to 8%. Historically, flows in this area have been transported to Spring Creek via an unnamed tributary. The site east of Overland Trail (Filings 4 thru 6) presently ex- ' ists as either agricultural or remain as bottomland vegetated with native grasses. The eastern portion of the site is traversed by Pleasant Valley Lake and Canal while Spring Creek ' dissects the South Easterly portion of the site. Areas adjacent to either of these features are populated with numerous trees, shrubs and bushes. During storm events, flow from Spring Creek enters Pleasant Valley Lake and Canal until breaching occurs. The accompanying backwater turns the southeastern portion of the site into a floodplain (reference Preliminary Drainage Plan). Proposed Description This site, in a fully developed condition, is proposed to be single family residences with two (2) on -site detention ponds and ' an open space drainageway meandering through the development. Buildout is planned as follows: Filing 4 - Complete by Winter 1990/Spring 1991 Filing 5 - Complete by Fall 1991/Spring 1992 Filing 6 - Complete by Fall 1992/Spring 1993 Filing 7 - Construction during Filings 5&6. The southern and eastern portions of the project will be bounded ' by a regional park, to be developed by the City of Fort Collins, approximately 20 Acres in size (reference Preliminary Drainage Plan) . PROCEDURE ' Design Criteria In accordance with the City of Fort Collins Storm Drainage Design Criteria, this residential development will be modeled for a 2 t year (minor) and a 100 year (major) storm event. The modeling method that will be used is the rational formula (see Section 3.2 in Fort Collins Drainage Criteria Manual). Also, detention storage will be calculated; using the Mass Diagram Method; per ' the City of Fort Collins Storm Water Utility as the difference between the 100 year developed flow and the 100 year historical flow. The detention ponds will be sized with staged outlet ' structures to release the historical rate of the occurring event. Pipe sizes were based on Concrete Pipe Inlet Control (Condition 1) with HW/D = 1 and 100 year developed flow rates (reference ' appendix). Offsite Drainage ' Discharge onto the site from property outside the P.U.D. comes from the area east of the hogback to the west edge of the P.U.D. Downstream facilities for safe transport of peak flows will be ' provided. Calculations for these facilities are included in Appendix. Onsite Drainage All on -site drainage will flow into one of two detention facilities which are part of the drainage way systems. The ra- tional method, mentioned above, is used to find peak discharge rates for sizing of transport systems. Detention facilities are sized using the Mass Diagram Method, the 100 year developed time ' of concentration, coefficients of permeability and frequency ad- justment factors and the 100 historical year release rate. For this study, the following coefficients of permeability were used; Historical Conditions C = .2 Filing 7 -(Estate Residential) C = .45 ' Filings 4-6 (Low Density Residential C = .5 See Appendix for Tabular Summaries of hydrologic parameters. � I Design Criteria PROCEDURE In accordance with the City of Fort Collins Storm Drainage Design Criteria, this residential development will be modeled for a 2 year (minor) and a 100 year (major) storm event. The modeling method that will be used is the rational formula (see Section 3.2 ' in Fort Collins Drainage Criteria Manual). Also, detention storage will be calculated; using the Mass Diagram Method; per the City of Fort Collins Storm Water Utility as the difference between the 100 year developed flow and the 100 year historical ' flow. The detention ponds will be sized with staged outlet structures to release the historical rate of the occurring event. Pipe sizes were based on Concrete Pipe Inlet Control (Condition 1) with HW/D = 1 and 100 year developed flow rates (reference appendix). Offsite Drainage ' Discharge onto the site from property outside the P.U.D. comes from the area east of the hogback to the west edge of the P.U.D. Downstream facilities for safe transport of peak flows will be ' provided. Calculations for these facilities are included in Appendix. ' Onsite Drainage All on -site drainage will flow into one of two detention ' facilities which are part of the drainage way systems. The ra- tional method, mentioned above, is used to find peak discharge rates for sizing of transport systems. Detention facilities are ' sized using the Mass Diagram Method, the 100 year developed time of concentration, coefficients of permeability and frequency ad- justment factors and the 100 year historical release rate. ' For this study, the following coefficients of permeability were used; ' Historical Conditions C = .2 Filing 7 -(Estate Residential) C = .45 Filings 4-6 (Low Density Residential C = .5 See Appendix for Tabular Summaries of hydrologic parameters. C ' • CONCLUSIONS AND RECOMMENDATIONS With the calculation methods used in this report, the detention ponds will be required to detain the amount of volume listed in the table below. Pond 1 100 year 100 year Offsite Required Historical Developed Area Flow Detention Basin Flow cfs Flow(cfs)es) cfs Volume (ft3) A-1 8.37 11.39 11.7 10,398 A-2 19.44 27.89 25.5 25,999 A-3 7.63 14.22 8.6 11,773 B-1 6.21 19.08 7.1 22,371 B-2 .95 .95 .7 -0- B-3 1.85 6.38 2.0 6,090 C 8.58 34.5 9.1 27,867 F-1 .93 3.25 1.0 3,035 Q = 53.96 Q=117.66 65.7 45.9 107,533/ 2.47 ac-ft. Pond 1 maximum release rate - (117.66 cfs-53.96 cfs)+45.9 cfs = 109.60 cT Pond 2 100 year 100 year Offsite Required Historical Developed Area Flow Detention Basin Flow (cfs) Flow(cfs) (Acres) cfs Volume (ft3) D 5.74 24.05 7.4 25,086 E 6.7 25.25 7.6 25,920 F 3.80 16.56 5.3 18,807 Q = 16.24 Q = 65.86 20.3 69,813 ft3/ 1.60 ac-ft. Pond 2 Maximum release rate = 65.86 cfs - 16.24 cfs = 49.62 cfs. 3 1 0 • REFERENCES Storm Drainage Design Criteria and Construction Standards by the City of Fort Collins, Colorado. May 1984. � I I I 11 11 11 11 11 11 I I 11 11 I I I I 11 I I 4 11 APPENDTX I\ I5.51It t (\`` �� } •.J� I. I ---+' "11 f t i 17 1 (� 4pj, a �'• , I \ �_ \, I ll_ .-aa= aJ 5 r2l • •• _ },JJ.. '- ✓ . ,P �-'!71] ) G'cl 'I • ST I fM 1I � .\� \ - _��"n 1 • 11 i 14'\ 1� N• �•Ioil ��' '1. �1 1. � I \I \ ` \ I j^ _� .• �• II-- f �c. \ )1 ' Y y 1�� `�'" '' �'�' l l ` ``1� �' ` • "' I • HIdium Q _»�-.�". -`T' I - ' d t •R �, 1 `--- ark.11 , '1y,"�+1' It}fir •� ` f �\' ; `t I IQ _. _ � _..; �� \'••II..� ��. � � / -• .�.�..•� 1 n" i I rit !) yy� f: -11•. t: a Nr fit (/ •` \Q � U� O - f' p ryr �; r �. \ ... � - 'k!•5?�. _• �Illc_ `,� �..t-0"\\r � \ � � Dixon '•. f PLEASANT ALL �' IIl 1i�ll�rt `` Cant LAKE 'AN D 'ANAL ` ' ,•\'��.��;,.'�. � :l � ri,�a dtiC, \'eRAICR_ ROAD I .. -.. �r sg9g `1� I IVV I' IN I .114 it L 1�• W 1 i � -1 - '' Calvet + 43 Trailer rafks 33Glaveh�• II - / .,��'+j Ovate' L.. Mt I - - N`_ u�)1'\' Lake F1t 1. '7'•� _ _ .. �. :I_. � ,•�1 t ,1, L ,�_.. CravPl `'�•is'�as� /- • • _ � ' - \ ,-t' Ida 1 � '�"'tir �i wr y.tt;rP�t't t lidsm• �99,; c sr'� � • rll' +rr<.1 `\ � •\YY�"i P Y�:1t� fib \\ t r� 1 . a 1t� l• .,r. , .\ •`i1�. �•_, t171�C4ti�y, Y1tily, ]��P, r f•i V- \ _ I�' - ,, + r - :• �.ryrgat. r jtr.' I� /% o i I 1 ) _,/' Itrlrte :6 �1 Me.:•" `vr,]!>4'y� j 1�;I `'I'o 1 '' =a�;\� J I �a j%�- CONCRETE PIPE INLET CONTROL 180 10,000 168 8,000 EXAMPLE (I) (2) (3) 156 — 6,000 D•42 inches (3.5 feet) 6. — 144 — 5,000 o•1zo cis - 5. — 4,000 �• nw 6. 132 D feet 3,000 — 5 4. 120 — 2,000 (2) 2.1 7.4 4,— 108 (3) 2.2 7.7 _ - 3. eD in feet 96 — 1,000 3• - — 800 - 04 — 600- - 500 / — 72 400 i 2. - = 300 1.5 c=Wi Z — 60 W U - 200 1.5 =— — Z / W - 54 / Tt a,- a w 48 j W — 100 > 80 �42 N — 60 H CL 1.0 O _ 50 HW ENTRANCE O W o 40 SCALE D TYPE Ir 10 - UJ J 36 30 W —.9 l (1) Square edge with Q 33 headwall 30 .9 Q — 20 (2) Groove end with QW — 30 headwall = ,8 (3) Groove end 8 — 2 7 projecting — 10 24 —8 —7_ — .7 — 6 To use scale (2) or (3) project 21 — 5 horlrontally to scale (1),then — 4 use straight Inclined line through 0 and 0 scales, or reverse as .6 3 illustrated. — .6 - - 2 15 5 [1.0 .5 5. 4. 3. 'm 1.5 W 9 .8 .6 I 12 HEADWATER DEPTH ,FOR HEADWATER SCALES 2133 CONCRETE PIPE CULVERTS BUREAU OF PUBLIC ROADS JAN.19E3 REVISED MAY 1964 WITH INLET CONTROL FORM 15A No Text 0 0 cr a. ------ M ----- ---------- - - O Lo L9 uml�lx,w.�„n� 1^ T — — — — — — — � t •i1'J w,u -- -- — -- — — o T VI 0 o 8 — d J � O FORD No Text 0 0 0 w COL. 0 J w w 0 Cc a w 0 0 HIM SON i FORM MASS I:).1'*)GPkAM ME-11-1CJI) to pET'I:EN-!":I:CJhI VOI....L.JsYll:':-f3 E='E;03(-(. I- - (:.)(.!A I l_ I--IC:1L_L_C. W FILING 7 t. OIYII~IE"N*'Fc:> ;; I-+AL:)1: I'� Al ' NIAX I lvl(..JI`1 RE=L..EAS)E (CF S) - E;AT I ("NAL_ E:_QUAT : ON - Q _= C I A "TIME-. OF C=ONCENTRC T T. ON (1..37 1a.7 T I (CIE CA 7: INFLOW _OW 0UTFI._0W S,T0RAGE (min (in/her•-) (C_U ft) (cu f•(_) (cu ft) {ac ft) :3 :.. 276 9 884.;. a .11511 67" ;4. 2 i). 14`i417 1() . ' 7 67 . _. 1. A' ;4(3., C38 Cfj '.^:. '7.4 6 . roc; r) , 11.1. 1. c 15 ..1_/6 6 17/,9().4 `%,:J•:..' 1()1..J/.4 C..�_.:1l._1 ,'�7f_) " . '(:)44'4'. 24 100 4 i(:39S. _'4 C.. _:f:371�) •-� r- 27 /6 4.e:) n r� 1 w..�.b(:)A. � 2 cs' er 1._ a a..J n 1{)C4.=.4 2 •er - 7- � !i.�.,()/ Yri .'�'76 4. 1 'A•47:1...7? 1.`..'�(.)66 i-1(i�. 7 �).'1Gl�i _' ' 5 ;276 . £3 ::'.6142. 48 171577 85615. A•8 � i . 1966 6 •C) ... ...../l., ... .. ...1 .:../._J 1 i:S. 4.::.'S_)S_)�J (.7 /'T. l).4 S), 17 (_)J7C� 45 . ;?'76 . 25 2N T746. 9 2: C99 6147. 9 (.). 141 136 0 -_.?76 ^9Af3A' '.�:;1.1(:) 4v;74 C.1CC41 .J..J ._ .._ ....,,8 ';ii..:_IC).24 ,._!t:,. 1 .._6A9.,:_Il• (.),c_)E:1(=;L3:L8 6..) " ( ;) f.••) cL 7. 1:) -':; (C) :1. 5 . - 6 C . (C)1 ? 1. 9 8 ''76 r' f c'.,:'..•..S`.,.f.34 14(?.J.76 -794(�, 16 -(). 1f3a's'(.3 9i i . 2*76 1.. {:3v5. ;'7 :: 7 . '24 11.5198 -7 •-r i . ^862 3 L (!C) ._ . '2 1 1 . / ,.4.L `;..' L}+_).ti:a'(_) 168(')4. �, -) . •'C3J % 8 l 1. (.) ...:' I {, 1 ..`:�::1 _ .:.h.a i .:. 48 .`..J,`_la 4? ._? 1 1 ?8 . `J - C) . 49801 120 ..,.'.76 1.. A•`:; :?11^().L , 44' 6 )26A. -- 2606)2. 5 _(). 98.--'1 e MASS DIAGRAM METHOD for DETENTION VOLUMES PROJECT: QUAIL HOLLOW FILING 7 COMMENTS:BASIN A2 MAXIMUM ALLOWABLE RELEASE (CFS) = 19.44 RATIONAL EQUATION: Q = CIA C = 0.31 A(area) = 25.5 TIME OF CONCENTRATION = TIME CA I INFLOW OUTFLOW STORAGE (min) _____________________________________________________________________ (in/hr) (cu ft) (cu ft) (cu ft) (ac ft) 5 7.905 9 21343.5 5832 15511.5 0.356095 10 7.905 7.3 34623.9 11664 22959.9 0.527086 15 7.905 6 42687 17496 25191 0.578305 20 7.905 5.2 49327.2 23328 25999.2 0.596859 25 7.905 4.6 54544.5 29160 25384.5 0.582747 30 7.905 4.15 59050.35 34992 24058.35 0.552303 35 7.905 3.8 63081.9 40824 22257.9 0.510971 40 7.905 3.5 66402 46656 19746 0.453305 45 7.905 3.25 69366.37 52488 16878.37 0.387474 50 7.905 3 71145 58320 12825 0.294421 55 7.905 2.8 73042.2 64152 8890.2 0.204090 60 7.905 2.6 73990.8 69984 4006.8 0.091983 70 7.905 2.3 76362.3 81648 -5285.7 -0.12134 80 7.905 2.05 77785.2 93312 -15526.8 -0.35644 90 7.905 1.85 78970.95 104976 -26005.0 -0.59699 100 7.905 1.7 80631 116640 -36009 -0.82665 110 7.905 1.55 80868.15 128304 -47435.8 -1.08897 120 7.905 1.45 82528.2 139968 -57439.8 -1.31863 3 MASS DIAGRAM METHOD for DETENTION VOLUMES PROJECT: QUAIL HOLLOW FILING 7 COMIII ENV TS:BASIN A MAXIMUM ALLOWABLE RELEASE (CFS) = 7.63 RATIONAL EQUATION: Q = CIA A(area) TIME OF CONCENTRATION = TIME CA I INFLOW OUTFLOW STORAGE (in/hr> (cu ft) (cu ft) (cu ft) (a ft) 5 3.354 9 9055.8 2289 6766.8 0.155344 10 3.354 7.3 14690.52 4578 10112.52 0.232151 15 3.354 6 18111.6 6867 11244.6 0.258140 20 3.354 5.2 20928.96 9156 11772.96 0.270269 25 3.354 4.6 23142.6 11445 11697.6 0.268539 30 3.354 4.15 25054.38 13734 11320.38 0.259880 35 3.354 3.8 26764.92 16023 10741.92 0.246600 40 3.354 3.5 28173.6 18312 9861.6 0.226391 45 3.354 3.25 29431.35 20601 8830.35 0.202716 50 3.354 3 30186 22890 7296 0.167493 55 3.354 2.8 30990.96 25179 5811.96 0.133424 60 3.354 2.6 31393.44 27468 3925.44 O.090115 70 3.354 2.3 32399.64 32046 353.64 0.008118 80 3.354 2.05 33003.36 36624 -3620.64 -0.0B311 90 3.354 1.85 33506.46 41202 -7695.54 -0.17666 100 3.354 1.7 34210.8 45780 -11569.2 -0.26559 110 3.354 1.55 34311.42 50358 -16046.5 -0.36837 120 3.354 1.45 35015.76 54936 -19920.2 -0.45730 m �� MASS DIAGRAM METHOD for N� DETENTION VOLUMES PROJECT: QUAIL HOLLOW FILINGS 4 THRU m� COMMENTS:BASIN B1 MAXIMUM ALLOWABLE RELEASE (CFS) = 6.21 RATIONAL EQUATION: Q = CIA | N� C = 0.625 1 A(area) = 7.1. TIME OF CONCENTRATION = TIME CA I INFLOW OUTFLOW STORAGE (in/hr) (cu ft> (cu ft> (cu ft) (ac ft) 5 4.4375 9 11981.25 1863 10118.25 0.232283 10 4.4375 7.3 19436.25 3726 15710.25 0.360657 15 4.4375 6 23962.5 5589 18373.5 0.421797 20 4.4375 5.2 27690 7452 20238 0.464600 25 4.4375 4.6 30618.75 9315 21303.75 0.489066 30 4.4375 4.15 33148.12 11178 21970.12 0.504364 35 4.4375 3.8 35411.25 13041 22370.25 0.513550 40 4.4375 3.5 37275 14904 22371 0.513567 45 4.437538939.06 16767 22172.06 0.509000 50 4.4375 3 39937.5 18630 21307.5 O.489152 55 4.4375 2.8 41002.5 20493 20509.5 0.470833 60 4.4375 2.6 41535 22356 19179 0.440289 70 4.4375 2.3 42866.25 26082 16784.25 0.385313 80 4.4375 2.05 43665 29808 13857 0.318112 90 4.437544330.62 33534 10796.62 0.247856 100 4.4375 1.7 45262.5 37260 8002.5 0.183712 110 4.4375 1.55 45395.62 40986 4409.625 0.101231 120 4.4375 1.45 46327.5 44712 1615.5 0.037086 9 MASS DIAGRAM METHOD for DETENTION VOLUMES PROJECT: QUAIL HOLLOW FILINGS 4 THRU 7 COMMENTS:BASIN B3 MAXIMUM ALLOWABLE RELEASE (CFS) = 1.85 RATIONAL EQUATION: Q = CIA C = 0.625 A(area) = 2 TIME OF CONCENTRATION = TIME CA I INFLOW OUTFLOW STORAGE (min) _____________________________________________________________________ (in/hr) (cu ft) (cu ft) (cu ft) (ac ft) 5 1.25 9 3375 555 2820 0.064738 10 1.25 7.3 5475 1110 4365 0.100206 15 1.25 6 6750 1665 5085 0.116735 20 1.25 5.2 7800 2220 5580 0.128099 25 1.25 4.6 8625 2775 5850 0.134297 30 1.25 4.15 9337.5 3330 6007.5 0.137913 35 1.25 3.8 9975 3885 6090 0.139807 40 1.25 3.5 10500 4440 6060 0.139118 45 1.25 3.25 10968.75 4995 5973.75 0.137138 50 1.25 3 11250 5550 5700 0.130853 55 1.25 2.8 11550 6105 5445 0.125 60 1.25 2.6 11700 6660 5040 0.115702 70 1.25 2.3 12075 7770 4305 0.098829 80 1,25 2.05 12300 8880 3420 0.078512 90 1.25 1.85 12487.5 9990 2497.5 0.057334 100 1.25 1.7 12750 11100 1650 0.037878 110 1.25 1.55 12787.5 12210 577.5 0.013257 120 1.25 1.45 13050 13320 -270 -0.00619 MASS DIAGRAM METHOD for DETENTION VOLUMES PROJECT: QUAIL HOLLOW FILINGS 4 THRU 7 COMMENTS:BASIN C MAXIMUM ALLOWABLE RELEASE (CFS) = 8.58 RATIONAL EQUATION: Q = CIA C = 0.625 A(area) = 9.2 TIME OF CONCENTRATION = TIME CA I INFLOW OUTFLOW STORAGE (min) _____________________________________________________________________ (in/hr) (cu ft) (cu ft) (cu ft) (ac ft) 5 5.75 9 15525 2574 12951 0.297314 10 5.75 7.3 25185 5148 20037 0.459986 15 5.75 6 31050 7722 23328 0.535537 20 5.75 5.2 35880 10296 25584 0.587327 25 5.75 4.6 39675 12870 26805 0.615358 30 5.75 4.15 42952.5 15444 27508.5 0.631508 35 5.75 3.8 45885 18018 27867 0.639738 40 5.75 3.5 48300 20592 27708 0.6360B8 45 5.75 3.25 50456.25 23166 27290.25 0.626497 50 5.75 3 51750 25740 26010 0.597107 55 5.75 2.8 53130 28314 24816 0.569696 60 5.75 2.6 53820 30888 22932 0.526446 70 5.75 2.3 55545 36036 19509 0.447865 80 5.75 2.05 56580 41184 15396 0.353443 90 5.75 1.85 57442.5 46332 11110.5 0.255061 100 5.75 1.7 58650 51480 7170 0.164600 110 5.75 1.55 58822.5 56628 2194.5 0.050378 120 5.75 1.45 60030 61776 -1746 -0.04008 I MASS DIAGRAM METHOD for DETENTION VOLUMES PROJECT: QUAIL HOLLOW FILINGS 4 THRU 7 COMMENTS:BASIN MAXIMUM ALLOWABLE RELEASE (CFS) RATIONAL EQUATION: Q = CIA C = 0.625 A(area) = 1 TIME OF CONCENTRATION = TIME CA I INFLOW OUTFLOW STORAGE (min) _____________________________________________________________________ (in/hr) (cu ft) (cu ft) (cu ft) (ac ft) 5 0.625 9 1687.5 279 1408.5 0.032334 10 0.625 7.3 2737.5 558 2179.5 0.050034 15 0.625 6 3375 837 2538 0.058264 20 0.625 5.2 3900 1116 2784 0.063911 25 0.625 4.6 4312.5 1395 2917,5 0.066976 30 0.625 4.15 4668.75 1674 2994.75 0.06875 35 0.625 3.8 4987.5 1953 3034.5 0.069662 40 0.625 3.5 5250 2232 3018 0.069283 45 0.625 3.25 5484.375 2511 2973.375 0.068259 50 0.625 3 5625 2790 2835 0.065082 55 0.625 2.8 5775 3069 2706 0.062121 60 0.625 2.6 5850 3348 2502 0.057438 70 0.625 2.3 6037.5 3906 2131.5 0.048932 80 0.625 2.05 6150 4464 1686 0.038705 90 0.625 1.85 6243.75 5022 1221.75 0.028047 100 0.625 1.7 6375 5580 795 0.018250 110 0.625 1.55 6393.75 6138 255.75 0.005871 120 0.625 1.45 6525 6696 -171 -0.00392 I MASS DIAGRAM METHOD for N� DETENTION VOLUMES PROJECT: QUAIL HOLLOW FILINGS 4 THRU 7 m� COMMENTS:BASIN D MAXIMUM ALLOWABLE RELEASE (CFS) = RATIONAL EQUATION: Q = CIA N� C = 0.625 A(area) = | TIME OF CONCENTRATION = 5.74 7.4 TIME CA I INFLOW OUTFLOW STORAGE __..... ________________________________________________________________ (in/hr) (cu ft) (cu ft) (cu ft) (ac ft) 5 4.625 9 12487.5 1722 10765.5 0.247141 10 4.625 7.3 20257.5 3444 16813.5 0.385984 15 4.625 6 24975 5166 19809 0.454752 20 4.625 5.2 28860 6888 21972 0.504407 25 4.625 4.6 31912.5 8610 23302.5 0.534951 30 4.625 4.15 34548.75 10332 24216.75 0.555940 35 4.625 3.8 36907.5 12054 24853.5 0.570557 40 4.625 3.5 38850 13776 25074 0.575619, 45 4.625 3.25 40584.37 15498 25086.37 0.575903 50 4.625 3 41625 17220 24405 0.560261 55 4.625 ` 2.8 42735 18942 23793 0.546212 60 4.625 2.6 43290 20664 22626 0.519421 70 4.625 2.3 44677.5 24108 20569.5 0.4�2210 80 4.625 2.05 45510 27552 17958 0.412258 90 4.625 1.85 46203.75 30996 15207.75 0.349121 100 4.625 1.7 47175 34440 12735 0.292355 110 4.625 1.55 47313.75 37884 9429.75 O.216477 120 4.625 1.45 48285 41328 6957 0.159710 I MASS DIAGRAM METHOD for DETENTION VOLUMES PROJECT: QUAIL HOLLOW FILINGS 4 THRU 7 COMMENTS:BASIN E MAXIMUM ALLOWABLE RELEASE (CFS) = 6.7 RATIONAL EQUATION: Q = CIA C = 0.625 A(area) = 8 TIME OF CONCENTRATION = TIME CA I INFLOW OUTFLOW STORAGE (min) _____________________________________________________________________ (in/hr) (cu ft) (cu ft) (cu ft) (ac ft) 5 5 9 13500 2010 11490 0.263774 10 5 7.3 21900 4020 17880 0.410468 15 5 6 27000 6030 20970 0.481404 20 5 5.2 31200 8040 23160 0.531680 25 5 4.6 34500 10050 24450 0.561294 30 5 4.15 37350 12060 25290 0.580578 35 5 3.8 39900 14070 25830 0.592975 40 5 3.5 42000 16080 25920 0.595041 45 5 3.25 43875 18090 25785 0.591942 50 5 3 45000 20100 24900 0.571625 55 5 2.8 46200 22110 24090 0.553030 60 5 2.6 46800 24120 22680 0.520661 70 5 2.3 48300 28140 20160 0.462809 80 5 2.05 49200 32160 17040 0.391184 90 5 1.85 49950 36180 13770 0.316115 100 5 1.7 51000 40200 10800 0.247933 110 5 1.55 51150 44220 6930 0.159090 120 5 1.45 52200 48240 3960 0.090909 ^ .x 0 MASS DIAGRAM METHOD for DETENTION VOLUMES PROJECT: QUAIL HOLLOW FILINGS 4 THRU 7 COMMENTS:BASIN F MAXIMUM ALLOWABLE RELEASE <CFS> = 3.8 RATIONAL EQUATION: Q = CIA C = 0.625 A(area) = 5.3 TIME OF CONCENTRATION = TIME CA I INFLOW OUTFLOW STORAGE (min) _____________________________________________________________________ (in/hr) (cu it) (cu it) (cu it) (ac it) 5 3.3125 9 8943.75 1140 7803.75 0.179149 10 3.3125 7.3 14508.75 2280 12228.75 0.280733 15 3.3125 6 17887.5 3420 14467.5 0.332128 20 3.3125 5.2 20670 4560 16110 0.369834 25 3.3125 4.6 22856.25 5700 17156.25 0.393853 30 3.3125 4,15 24744.37 6840 17904.37 0.411027 35 3.3125 3.8 26433.75 7980 18453.75 0.423639 40 3.3125 3.5 27825 9120 18705 0.429407 45 3.3125 3.25 29067.18 10260 18807.18 0.431753 50 3.3125 3 29812.5 11400 18412.5 0.422692 55 3.3125 2.8 30607.5 12540 18067.5 0.414772 60 3.3125 2.6 31005 13680 17325 0.397727 70 3.3125 2.3 31998.75 15960 16038.75 0.368199 80 3.3125 2.05 32595 18240 14355 0.329545 90 3.3125 1.85 33091.87 20520 12571..87 0.288610 100 3.3125 1.7 33787.5 22800 10987.5 0.252238 110 3.3125 1.55 33886.87 25080 8806.875 0.20217B 120 3.3125 1.45 34582.5 27360 7222.5 0.165805