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28545-3 - LQ Resort and Club Entry Driver IE Co y I ? C---'�'\ 1 LA QUINTA RESORT AND CLUB 1 HYDROLOGY AND HYDRAULIC REPORT FOR ' ENTRY DRIVE IMPROVEMENTS PREPARED BY: STANTEC CONSULTING, INC. ' 73 -733 FRED WARING DRIVE, SUITE 100 PALM DESERT, CA 92260 PREPARED FOR: ' LA QUINTA RESORT AND CLUB 49 -499 EISENHOWER DRIVE ' LA QUINTA, CA. 92253 September 18, 2008 1 Prepared Under the Supervision of Brooks D. Franklin R.C.E,61887 Expiration Date: September 30, 2009 ' V:\2017\active\20171 10600 \civil\report\drainage\Hydrology and Hydraulic Report.doc 1 ` ' LA QUINTA RESORT AND CLUB HYDROLOGY AND HYDRAULIC REPORT FOR ' ENTRY DRIVE IMPROVEMENTS TABLE OF CONTENTS: ' I PURPOSE AND SCOPE II DESIGN OF PROPOSED IMPROVEMENTS III RATIONAL METHOD CALCULATIONS -100 YEAR IV CATCH BASIN SIZING CALCULATIONS ' V STORM DRAIN PIPE NETWORK ANALYSIS ' VI HYDROLOGY MAP r 1 V:\ 2017\ active\ 2017110600 \civil\report\drainage\Hydrology and Hydraulic Report'doc 1 I PURPOSE AND SCOPE The purpose of this report is to provide a hydraulic and hydrologic study to accompany the Entry Drive Improvement Plan for the proposed revisions to the La Quinta Resort's main entry drive. The resort is located on both sides of Eisenhower Drive in the City of La Quinta. The main entry drive is located off of Eisenhower Drive, on the west side, between Avenida Fernando (to the north) and Avenue 50 (to the south) and is a full movement, three -way intersection with no traffic signal. ' This report summarizes the hydraulic and hydrology requirements for the entry drive, and considers the existing site and future adjacent improvements. The existing entry drive is asphalt concrete and approximately 40' wide by 600' in length. The entry drive is not impacted by adjacent or off -site storm flows (see hydrology map). There are two existing 15 "x15" grated inlets at the westerly end of the entry drive which, intercept the tributary storm flows. The existing drive is essentially flat with similar elevations at the westerly and easterly ends. With regard to an emergency overflow, should the existing grated inlets become plugged, the storm flows would be directed along the entry drive (from west to east) and into Eisenhower Drive. An existing 24" storm drain pipe runs parallel to the entry drive, within the existing planning area to the north. This pipeline accepts the entry drive storm flows (as described above) as well as storm flows from two existing inlets in the hotel "drop off' area. The flows are conveyed via gravity eastward to a combination drywell and pump station wet well. No improvement plans for the 24" onsite gravity storm drain were available from the City or the hotel operator. However, the hotel operator was able to provide existing plans for the pump station wet well and associated 8" PVC force main. These plans indicate that storm flows are piped from the wet well (located behind the northerly curb return/entry walls at the entry drive) approximately 1,800 feet south along Eisenhower and then easterly to an existing golf course lake on the east side of Eisenhower. II DESIGN OF PROPOSED IMPROVEMENTS The proposed improvements consist of a new entry drive with two, twenty -foot lanes (with enhanced concrete pavement or pavers) ' divided by an eight -foot planted median. The existing drain inlets will be replaced with new catch basins and two additional inlets will be added near the middle of the drive. The proposed improvements will be "private ", but will meet the current City of La Quinta standards. Note that the proposed drainage improvements "tie into" a system which is over twenty years old, and is part gravity and part force main. Further, the existing and proposed storm flows at the entry drive are essentially the same, and the emergency overflows are also the same. Therefore, no analysis of the pump station or other onsite existing facilities is included in this report. V:\2017\active\201 7110600 \civil\report\drainage\Hydrology and Hydraulic Report.doc III RATIONAL METHOD CALCULATIONS —100 YEAR In accordance with the Riverside County Flood Control Hydrology Manual and City of La Quinta Engineering Bulletin #06 -16, Rational Method calculations are typically used to estimate flow rates to model street flow capacities and size catch basins. However, since the tributary areas are small (varies from 0.12 acre to 0.18 acre) and the proposed inlets are all in sump conditions, we have utilized a simplified approach to developing storm flows as suggested in Engineering Bulletin #06 -16. Conservatively using 5cfs /acre for a 100 -year storm event, we have: INLET INLET TYPE INLET SIZE TRIBUTARY 100 -YEAR AREA FLOW CB -1 COMBINATION 2'x3' 5,010 S.F. 0.6 cfs INLET IN A SAG CB -2 COMBINATION 2'x3' 5,980 S.F. 0.7 cfs INLET IN A SAG CB -3 COMBINATION 2'x3' 7,800 S.F. 0.9 cfs INLET IN A SAG CB -4 COMBINATION 2'x3' 7,800 S.F. 0.9 cfs INLET IN A SAG IV CATCH BASIN SIZING CALCULATIONS According to the Federal Highway Administration's (FHWA) guidelines for Drainage of Highway Pavements (HEC -12), the interception capacity of.the combination inlet in a sag condition is essentially equal to that of a grate alone in weir flow, unless the grate opening becomes clogged. In the event that the grate portion of the inlet becomes clogged, the inlet acts as an orifice and the curb opening portion of the inlet is used to provide the inlet capacity. Combination inlets are considered advisable for use in sags because of their ability to continue to provide inlet capacity even when clogging of the grate occurs. All combination curb opening — grate inlets proposed at the La Quinta Resort entry drive are Nyloplast 2' X 3' Diagonal Curb Inlet Grates with 7" hood settings (7" from top of curb to top of grate). A copy of the inlet capacity chart for inlets in sump conditions (from FHWA HEC -12, Chart 11) is attached. The chart shows that the inlet capacity for a grated inlet is 5.7 cfs after a recommended factor of safety of 2.0 (or 50% clogging) is applied. Therefore, all inlets have the capacity to intercept the 100 -year storm flow. V:\ 2017\ active\ 2017110600\ civil\report \drainage\Hydrology and Hydraulic Report.doc V STORM DRAIN PIPE NETWORK ANALYSIS The storm drain pipe network analysis (or hydraulic calculations) were prepared using the ' StormCAD software. The catch basins and pipe segments are named so that the report and plan correspond. Catch basins are identified as CB -1 to CB -4 and pipe segments are ' identified as P -1 to P -4. The "tie -in" pipe is the existing 24" storm drain pipe north of the entry drive. t Note the analysis was performed only for the 100 -year event since all of the inlets were in sump condition. Further, since the existing 24" "tie -in" pipe drains into a drywell, with an overflow connection to the pump station wet well, we utilized this overflow elevation in our ' calculations as the corresponding depth of ponding in the "tie in" pipe, for both pipe segments P -2 and P -4. Based on an elevation of 38.17, the hydraulic grade line for P -4 at the "tie -in" is above the pipe soffit. ' The hydraulic calculations indicate that proposed 12" pipes are satisfactory to convey the storm flows to the existing 24" storm drain. Note that the existing piping is only 6" diameter ' PVC pipe. Velocites for the proposed pipe vary between 5.4 to 12.5 fps. See attached StormCAD reports. ' VI HYDROLOGY MAP ' See attached hydrology map. V:\2017\active\20171 10600 \civil\report\drainage \Hydrology and Hydraulic Report.doc 1 l4ests Vvere. ot �and ckaWdown occurs'� I- t&Dthmeasurements from eip9h'i In '.1aken' theveh, menta IN 1w Ve here 4heasurernentstiwere,rna�de-ah'd the weir.'. een� -poi�fw 4.N N, _openihg.inlet is, at the,(5dge'-of thd"gijttdr, d#4,th6effd6tiv'e.weirc. eir:16,patiow, -v-depi�s§ed'cuih- 7is 46pc`.Aden1,6fi,t 4=t .a th6"6urb opening: The'w6ir Me ;6�idth, 6fthe', d6p-t `U- esse gutter oc I aii _-f& a curb -openmginlet thaftis4fi&,de'pi6se&is at the lip of the. curb "o'p'en'i'n"g,,,aild,,,its 16 '49 rth" 'IS.''.1 �ualthat ot-the:ifilk. Liffiited:63�periments andgkiro6lation"of the results bf te'sts'Ofi'aePressedinieis,.,I .,to nd i t'e-,4 h a t, t „ -i1.4. - e i r, cc .'b e fti cent -, foF' curb- opening ' - .'I " - inlets ' '-ididly'equd ! I'to,thdt" withbut.i. epression- isapprox"in k v, A r - G' -A.dep'fessed ciirb.�.oD'e'n'i"ng",in"ie-'t'.*,,.,.;�. A, :L le,equation fio-P fhe`-,Intefcdption dapacity•of d'dpprdsse'&cu' rb-'6-v'Te­n'jn_g' Inl6f6perating-a§ a,weir.js:_ "I)*;. IiN 4Z J4 V • It I ti Err a4 Za ILI �Z L lIr' t 03 wr 14 f .-It— uti:L 3t.( .40 14' -4� f4 ".77- Al 4 M + "4: 14 1 v _V. It. r v, k 'A "41t, 47 1`A, IN j+EC-_ _IS jo S -ie Y-i 1%P fait'�e t capacity in sump C n n, Cfi�rt, 1 L inie 6 dit 4 A Qla t • tw(v+ 1 1% 13 (P I'd 441 `4 3+ - ns A It - 0 a LN- ?z - YN 'WI tn- t 4 .7 1 opt -*4, Z 4 L v "1 4 AI, V "I , _ • If T. + '.0 It wr 14 f .-It— uti:L 3t.( .40 14' -4� f4 ".77- Al 4 M + "4: 14 1 v _V. It. r v, k 'A "41t, 47 1`A, IN j+EC-_ _IS jo S -ie Y-i 1%P fait'�e t capacity in sump C n n, Cfi�rt, 1 L inie 6 dit 4 A Qla t • tw(v+ 1 1% 13 (P I'd 441 `4 3+ - ns A It - i CB -2 [Tie In -2 ci Vi Z r N ' li r N X ' Ul ' Bentley Systems, Inc. Haestad Methods Solution Bentley StormCAD V8 XM Edition Pipel.stc Center [08.09.081.00] 27 Siemon Company Drive Suite 200 W Page 1 of 1 ' 9/22/2008 Watertown, CT 06795 USA +1- 203 - 755 -1666 .� rr' �cBenFAngle°. � ���< � ,;Bend Loss:C oefficient,, Kb'', ,u. Calculation Detailed Summary 0 15 (CB -1, CB -2, P -1 AND P -2) 30 Element Details 45 0.47 60 ID 13 Notes 90 Label Base Calculation Options Hydraulic Summary Flow Profile Method Backwater Analysis Average Velocity Method Actual Uniform Flow Velocity Number of Flow Profile 5 Minimum Structure 0.00 ft Steps Headloss Hydraulic Grade 0.001 ft 5.000 min Convergence Test Inlets Neglect Side Flow? FALSE Active Components for Grate and Curb Combination Inlets In Sag Neglect Gutter Cross TRUE Active Components for Grate and Curb Slope For Side Flow? Combination Inlets on Grade HEC -22 Elevations Considered 0.5 ft 1 Equal Within Consider Non -Piped False Half Bench Submerged 0.95 Plunging Flow Flat Submerged 1 0.15 Flat Unsubmerged 1 0.75 Depressed Submerged 1 0.07 AASHTO Expansion, Ke 0.35 0.5 Contraction, Kc 0.25 1.3 Bend Angle vs. Bend Loss Curve �cBenFAngle°. � ���< � ,;Bend Loss:C oefficient,, Kb'', ,u. 0 0 15 0.19 30 0.35 45 0.47 60 0.56 75 0.64 90 0.7 Generic Structure Loss Governing Upstream Pipe Pipe with Maximum QV Selection Method Catchment Summary Labe) Area' Time of;Concentraaon Retignal C. Catchment,CA -: (acres) (min) (acres) Catchment Intensity Catchment RAbna['Flow'. (in /hr. Conduit Summary Label Conduit Descripbon , :Conduit Shape Branch ID Subnetwork OutfaI Flow,: .. ,,. ft3 S= P -1 Circular Pipe - 12.0 Circular Pipe 1 Tie In 0.7 CB -2 in Tie In 0.6 1.3 P -2 Circular Pipe 12.0 Circular Pipe 1 Tie In 1.3 in Veloaty (Average):: Hydraulic Grade Hydraulic Grade Depth (In) .Depth (Out)' ' l (ft/s) Line (in) ft 5.44 40.35 39. 54 0.35 0.48 8.51 39.54 38.17 0.48 0.6 Node Summary :Label Element Type Subnetwork Outfall- _ Flow (Total Surface) Flow (Total Out) ft3s ft3s CB -1 Catch Basin Tie In 0.7 0.7 CB -2 Catch Basin Tie In 0.6 1.3 Elevation_(Ground) Elevabon;,(Invert), Energy Grade.Une(In) Energy Grade Une`(qut (f1). _. (�)� 43 40 40.48 40.1 43 39.06 39.73 39.E Inlet Summary Label: Inlet Type Inlet TYpe {Inlet),' Inlet 71710 w (Total Intercepted): a (ft3 /S) CB -1 Percent Capture (N /A) (N /A) 0 CB -2 Percent Capture (N /A) (N /A) 0 Flog (Total Bypassed),., Bypass Target Capture Effiuency �,,; Guttei De' p ft h Gutter,SSpread (ft3 /s) Q -(Calculated o .. ,. 0 <None> 100 0 0 0 <None> 100 0 0 Pipel.stc Bentley Systems, Inc. Haestad Methods Solution Center 9/22/2008 27 Siemon Company Drive Suite 200 W Watertown, CT 06795 USA +1- 203 - 755 -1666 Bentley StormCAD V8 XM Edition [08.09.081.001 Page 1 of 1 1 1 1 1 1 1 1' 1 I, I I CB-4 Tie In e 7 N UT Z 1-� W Bentley Systems, Inc. Haestad Methods Solution Bentley StormCAD V8 XM Edition Center [08.09.081.00] 27 Siemon Company Drive Suite 200 W Page 1 of 1 Watertown, CT 06795 USA +1- 203 - 755 -1666 Calculation Detailed Summary (CB -3, CB -4, P -3 AND P-4) Element Details ID 13 Notes Label Base Calculation Options Hydraulic Summary Flow Profile Method Backwater Analysis Average Velocity Method Actual Uniform Flow Velocity Number of Flow Profile 5 Minimum Structure 0.00 ft Steps Headloss Hydraulic Grade 0.001 ft 5.000 min Convergence Test Inlets Neglect Side Flow? FALSE Active Components for Grate and Curb Combination Inlets In Sag Bend Angle Behd Loss Coefficient, Kb- de' ees Neglect Gutter Cross TRUE Active Components for Grate and Curb 0.19 Slope For Side Flow? Combination Inlets on 45 ' 60 Grade 75 0.64 90 0.7 HEC -22 ' Elevations Considered 0.5 ft 1 Equal Within Consider Non -Piped False Half Bench Submerged 0.95 Plunging Flow ' Flat Submerged 1 0.15 Flat Unsubmerged 1 0.75 ' Depressed Submerged 1 0.07 AASHTO Expansion, Ke 0.35 0.5 Contraction, Kc 0.25 1.3 ' Bend Angle vs. Bend Loss Curve Bend Angle Behd Loss Coefficient, Kb- de' ees 0 0 15 0.19 30 0.35 45 0.47 60 0.56 75 0.64 90 0.7 Generic Structure Loss Governing Upstream Pipe Pipe with Maximum QV Selection Method Catchment Summary Label Tirne,oft6hcentratibn Catchment a- Q!qes),�',, I CatchmentIntensity ,,.,", Catchment Rational onal� I ow Conduit Summary Description Conduit -Shape 08 Subnetwork — '. q I'll XonduitDe§c 6rid 1 5 pe, F'T ft3 S) P-3 Circular Pipe - 12.0 Circular Pipe 1 Tie In 0.9 CB-4 C in e In 0 0.9 1 1.81 P-4 Circular Pipe - 12.0 Circular Pipe 1 Tie In 1.8 in I Velocity Hydraulic Grade Depth (In) Depth (Out) .r (Average) rade (ft/s) Line (In) Line (out) 0 j 5.851 40.41 39.631 0.41 0.57 12.53 39.63 38.17 0.571 2.52 Node Summary La bel len e t'T ype Subnetwoi Outfall' �Fld (Total Surface) Flow ff6fahbdt MIA) -B-3 Catch Basin T Tie In 0 0.91 0 0 CB-4 C Catch Basin e e In 0 0.9 1 1.81 �Elevation (Ground) 77--, Elevat on,,(Invet) Energy Grade Line (In) gY,GFade Line (Out MY 431 411 40.551 40.! 43 39.06 39.87 391 Inlet Summary Inlet +,jpw:(Totarjhteh!epted) Inlet ,, n e Type "(Inlet): '71t p CB-3 Percent Capture (N/A) (N/A) 0 0 CB-4 Percent Capture I (N/A) (N/A) 1 Flow,(Total. Bypassed Target 1 Capture U Eff c e n 05ffer Gutter Spread (ft3 /s) (Calculated) {in) 01<None> 100 0 1 0 0 1 100 1 0 <None> 1 Pipe2.stc Bentley Systems, Inc. Haestad Methods Solution Bentley StormCAD V8 XM Edition Center [08.09.081.00] 9/22/2008 27 Siemon Company Drive Suite 200 W Watertown, Page 1 of 1 CT 06795 USA +1-203-755-1666 IN THE CITY OF LA QUINTA, STATE OF CALIFORNIA HYDROLOGY, MAP LA QUINTA RESORT AND CLUB PARCEL MAP 28545-1 LOCATED IN A PORTION OF THE SE 1/2 OF SECTION 36, T5Sj R6E, SBM CITY OF LA QUINTA LEGEND SUBAREA BOUNDARY Q=5,47 . CFS SUBAREA RUNOFF FOR 100 YEAR. EMERGENCY OVERFLOW - DIRECTION OF FLOW DIRECTION OF STORM FLOW CIB-# CATCH BASIN NUMBER (CORRESPONDS TO REPORT/PLAN) PA PIPE SEGMENT NUMBER (CORRESPONDS TO REPORT/PLAN) HYD DROLOGY MAP SCALE: 1"=30'