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HomeMy WebLinkAboutCT 98-14; Thompson/Tabata; Tentative Map (CT) (88)WILSON ENGINEERING DEXTER S. WILSON, P.E. ANDREW M. OVEN, P.E. STEPHEN M. NIELSEN, RE. MEMORANDUM 615-006 To: Gregg Linhoff, Standard Pacific RECEIVED From: Andrew Oven, Wilson Engineering ejjrp gy CITY OF Date: September 7, 1999 PLANNft Subject: Offsite Sewer Analysis for the Thompson Property in Carlsbad The proposed Thompson property development is located in the southwestern quadrant of the City of Carlsbad. It is east of Interstate 5 and on either side of Poinsettia Lane west of Alga Road. It is bounded on all sides by existing single-family residential development. The purpose of this memorandum is to update the September 10, 1998 memorandum which provided the results of our preliminary offsite sewer analysis. The analysis was done to verify that existing gravity sewer system lines south of the Thompson property will have sufficient capacity to accommodate flows from the proposed development. The proposed Thompson property development and surrounding areas gravity sewer to the existing North Batiquitos Sewage Lift Station. This sewage lift station has been upgraded within the last three years to provide sufficient capacity for this entire service area. Therefore, there is not a concern about pumping station capacity for the proposed Thompson property project. However, the January 1992 Sewer Master Plan for the City of Carlsbad identified a trunk sewer improvement south of the proposed Thompson project. Since the 7O3 PALOMAR AIRPORT ROAD, SUITE 3OO • CARLSBAD, CA 92OO9 • (760)438-4422 • FAX (76O) 438-O1 73 Gregg Linhoff September 7, 1999 Page 2 Thompson property is one of the last to be developed within this portion of the sewer basin served by the North Batiquitos Sewage Lift Station, it is necessary to insure that additional flows generated by the Thompson property project will be accommodated within the existing gravity sewer system. Exhibit A attached to this memorandum shows the computer model sewer system which was used to evaluate available capacity in the existing system. Two computer run printouts are attached for your review. The first shows the existing system without the Thompson property, and the second shows the existing system with the addition of 268 proposed single-family dwelling units. This total includes 253 single family dwelling units within the Thompson property project, and an estimated 15 single family dwelling units that may be built sometime in the future within the two "Not-A-Part" parcels. Thus, this second computer run models the buildout condition for this portion of the North Batiquitos Sewage Lift Station gravity sewer basin. The results show that under ultimate conditions the maximum depth-to-diameter ratio within any reach of the gravity sewer south of the Thompson property is 0.71. This means that the pipeline is 71 percent full by depth. Typically for existing systems, a pipeline that is less than 75 to 80 percent full by depth is considered to be acceptable. Therefore, our conclusion is that no further upgrades are necessary within this gravity sewer basin upon buildout of the Thompson property project. This conclusion is consistent with the conclusion reached by the North Batiquitos Pump Station Service Area Report prepared by Wilson Engineering, dated October 23, 1992. This study concluded that based on the Master Plan buildout of the basin the maximum depth-to-diameter ratio within the gravity sewer would be 70 percent. Please let us know if you have questions regarding the information presented or if you need additional information or analysis. A0:lb Attachment ?/ 9/98 13:24546 PA6E i 3E8E8 ANALYSIS GEOMETRY City of Carlsbad - Thompson Property Se»er Analysis Down Slope n or L'Dia-s END OF STRIP — Design Criteria — d/D Flow i. 4 7 13 13 16 19 22 25 28 31 34 37 48 43 46 49 52 55 53 61 64 4tfH 46 78 73 76 79 82 .889533 .815508 .333488 .318983 .325833 .823138 .328688 .823838 ,834383 .323883 .835888 .851933 .117988 .832988 .334338 .852888 .863133 ,342880 .355388 .851783 .362388 .373338 •tt+tm+tw .858308 .877988 .851538 ,363738 .345883 .328883 4 7 13 13 14 19 22 25 23 31 34 37 48 43 46 49 52 55 53 61 64 183 •tttft-H-M 73 73 76 79 82 588 .313 .813 ,813 .813 .813 .813 .813 .813 .313 .813 .813 .813 .813 .313 .813 .313 .313 .813 ,813 .813 .313 .313 •tm END .813 .313 .313 .813 .813 .813 18 13 13 18 3 3 3 3 8 3 3 8 3 3 3 b 3 8 3 8 3 8 OF STRIP ++n 3 8 3 8 8 3 .93 .93 .93 .93 .93 .93 .93 .93 .93 .93 ,93 ,93 .93 .93 ,93 .93 .93 .93 .93 .93 .93 .93 H-TttftH-*« .93 .93 ,93 .93 .93 .93 1.5 1.9 1.4 1.6 1.3 1.3 1.2 1.2 1.5 1.4 1,6 1.9 2.9 1.5 .5 1.9 2.1 1.7 2.8 1.9 2.1 2.2 •mmw 2.8 2.3 1.9 2,1 1.8 1.2 4.3 5.5 4,1 4.7 6.1 5.8 5.5 5.4 7.1 6.4 7.2 8.7 13.2 7.3 2.4 8.3 9.6 7,9 9.3 8.7 9.6 18.2 t+tmt 9.3 18.7 8.7 9.7 3.1 5.4 37 232 235 288 211 214 217 223 223 .321638 .831288 .065888 .855833 ,378838 .822338 ,828338 ,319833 .819888 282 285 238 211 214 217 228 223 333 .813 .813 .813 .813 .313 .813 .813 .313 .313 3 8 3 8 8 3 3 3 8 .93 .93 .93 .93 .93 .93 .93 .93 .93 1.2 2.4 2.1 2,3 2.2 1.3 1.2 1.2 1.2 5.6 18.9 9.3 9.3 18.2 5.8 5.4 5.3 5.3 OF AREA • SE8ER ANALYSIS UNITS City of Carlsbad - Thompson Property Sewer Analysis DISTANCE DIfiftETER FLQ8 ELEVATION AREA FEET INCHES HSD FEET ACRES 9/ 9/93 13:24;52 PA6E 1 SE8D? ANALYSIS LOAD SOHSARY City of Carlsbad - Thoapson Property Sewer Analysis Sanbale Total Contributed Point Area Flow Source 7 11.38 .88 .88 13 16.00 .83 ,80 13 13.38 .88 .88 14 111. 88 .82 .80 25 41.88 .81 .88 31 39.88 .81 .00 37 1.88 .88 .88 43 1848.88 .23 .08 49 18.88 .88 .88 52 28.38 .31 .88 55 11,88 .08 .38 58 27.33 .81 .88 61 31.83 .11 .03 44 13.88 .33 .33 73 8,88 .38 .83 73 12.88 .33 .83 74 38,88 .31 .38 79 5.38 .88 .88 82 26.88 .81 .38 235 5.83 .88 .83 288 13.88 .83 .88 211 49.88 .82 .88 214 6.88 .83 .88 217 9.88 .88 .83 223 54.83 .81 .88 223 44.83 .31 .88 tit WARNISS ttt ZERO OR NEGATIVE FL08 !H THIS REACH ttti 9/ 9/98 13:24:55 PAGE 2 SESER ANALYSIS SANITARY LOAD APPLICATIONS City of Carlsoad - Thospson Property Sewer Analysis Slope Dias Capa- Area Flow Point Average Peak v'el- Depth Under Capacity Up 388 223 228 217 214 211 288 285 282 W 1 583 82 79 n 73 78 m & 133 64 61 53 55 52 49 73 BOW: ~T7 iii> 223 217 214 211 288 285 232 37 MHIW5 82 79 76 73 73 46 lARHISG 64 61 58 55 52 49 46 46 ,81988 .81988 ,32888 .82288 .37388 ,85588 ,36583 .38128 .82168 W ZERO .82388 .84583 .36373 .85158 .87798 ,85838 W ZERO .87888 .86238 .85178 .35588 .34288 .36318 .85283 3 8 3 3 3 8 8 8 3 OR 8 8 8 3 3 3 OR 8 8 3 8 8 3 3 city. 1,16 1.16 1.19 1.27 2.22 1.97 2.14 2.39 1.23 NEGATIVE 1.19 1.73 2.12 1.91 2.34 2.33 NEGATIVE •-, .-,.-.il.-ii, 2,13 1.91 1.97 1.74 2.11 1,93 Input Source .33 .33 .83 44.83 .81 .88 56.88 .81 .88 9.03 .38 .83 6.88 .33 .33 69.88 .82 .88 13.88 .38 .83 5.88 ,88 .88 .83 .33 .88 FLOS IN THIS .REACH Wi .83 .33 .33 26,83 .81 .38 5.38 ,83 ,38 33.38 .81 ,88 12.88 ,38 .33 8.38 .83 .33 FLGS IN THIS REACH JW .33 .33 .33 13,83 .38 .33 31.88 .81 .88 27.88 .31 .83 11.38 .88 ,83 23,88 .61 J8 18.38 M M Flew Flos ,33 .33 .81 ,83 .82 ,86 ,82 .37 .83 .87 .84 .11 .84 ,11 ,84 .12 ,84 .12 riin or r--rr>i r, .tnt/ or aihir * .38 .33 .81 .82 .81 .82 ,81 .34 .32 .34 .82 .85 CM« i"*C •"'Ttl1 T D 'cm/ ur olhir T .33 .38 .38 .81 .81 .83 .31 .34 .82 .35 .82 .86 .83 ,87 ,8 ocity ,8 2,1 2.6 2.3 4.3 4.4 4.7 5.3 3.3 .3 2.1 2.5 3.2 3.9 3.7 .3 2.4 2.9 3.3 3,2 3.3 3,8 Ratio Replace Relief Identification ,38 .12 .16 ,16 .13 .16 .16 .16 .22 .88 ,86 .36 .18 .18 ,12 .83 .86 ,89 .18 .12 ,12 ,13 .53 .27 .32 .43 9/ 9/93 13:25: I PA6E 3 SESES ANALYSIS SANITARY LOAD APPLICATIONS City of Carlsbad - Thospson Property Sewer Analysis HH SK Slope Dias Capa- Area Flow Point Average Peak V'ei- Depth Under Capacity Up Down 43 282 37 34 31 23 25 22 19 16 13 li 7 4 37 37 34 31 28 25 22 19 16 13 18 7 4 1 .11798 .35198 .83588 .82888 .83488 .82888 .82368 .82318 .82588 .81898 .88348 .81558 .88958 a 8 8 8 8 8 8 3 8 13 13 13 18 city, Input Source Flow 2.83 .88 .88 1.91 1.88 .88 1.57 M .88 1.41 39.88 .81 1.55 .88 .88 1.19 61.88 .81 1.21 .88 .88 1.28 .88 .88 1.33 111.88 .82 1.59 13.88 .38 1,48 16.88 .88 1.93 11.88 .33 1.43 .33 .33 .88 .27 .8 .88 .32 .88 .32 .88 .33 .38 .33 .88 .34 .88 .34 .83 .34 .83 .37 .88 .37 .88 .37 .88 .37 .08 .37 Flow ocity Ratio .66 .76 .76 .78 .78 .81 .81 .81 .87 .87 .88 .88 .33 9.3 7,5 6.5 6.1 6.5 5.4 5.4 5.7 5.9 4.4 3.9 5.3 4.2 .34 .46 .51 .56 .52 .64 .63 .61 .62 .55 .68 .58 .58 AREA il 9/93 14;55;59 SE»ER ANALYSIS GEOMETRY City of Carlsbad - Thospson Property Seser Analysis FASE 1 HH DSHfi i 4 7 113 13 16 19 22 25 28 31 34 37 43 43 46 49 52 55 58 61 64 HH — Design Criteria — Slope .889588 .315588 .388483 . 818988 .825888 .823188 .828688 .828888 .834888 .823888 .835888 .851988 .117988 .332988 .884888 .852888 .863188 .842888 .855888 .851788 .862388 .878888 Up 4 7 18 13 16 19 22 25 28 31 34 37 48 43 46 49 52 55 58 61 64 188 n or C .813 .813 .813 .813 .813 .813 .313 .813 ,813 .813 ,313 .813 .813 .813 .813 .813 .813 .813 .813 .813 .813 .813 44444444444444444444444444444444 END Of 46 78 73 76 79 82 .858388 .877938 .851588 .863708 J45888 .828888 78 73 76 79 82 588 ,813 .313 .313 .813 .313 .813 44444444444444444444444444444444 END OF 37 282 285 288 211 214 217 22g 223 .mm .881283 .865883 .055008 .078888 .822888 .828888 .819088 .§19388 202 285 283 211 214 217 228 223 383 ,313 .813 .813 J13 .313 .813 .313 .113 .813 Bias 13 11 18 18 3 8 a 8 8 3 8 8 8 8 8 3 8 8 8 8 8 3 STRIP 8 8 8 3 8 3 STRIP 3 8 8 8 3 8 3 8 3 d/D .93 .93 .93 .93 .93 .93 .93 .93 .93 .93 .93 .93 .93 .93 .93 .93 ,93 .93 .93 .93 ,93 .93 Flow 1.5 1.9 1.4 1.6 1.3 1.3 1.2 1.2 1.5 1.4 1.6 1.9 2.9 1.5 .5 1.9 2.1 1.7 2.8 1.9 2.1 2.2 Veloc 4.3 5.5 4,1 4.7 6.1 5.8 5.5 5.4 7.1 6,4 7.2 8.7 13.2 7.3 2.4 8.8 9.6 7.9 9.8 8.7 9.6 13,2 44444*4f 4444444444444444444+444 .93 .93 .93 .93 .93 .93 2.3 2.3 1.9 2.1 1.8 1.2 9.3 18.7 8.7 9.7 3.1 5.4 4444444444444444444444444444444 ,93 .93 .93 .93 .93 .93 .93 .93 ,93 1.2 2.4 2.1 2.8 2.2 1.3 1.2 1.2 1.2 5.6 18.9 9.8 9.0 1§.2 5.8 5.4 5.3 5.3 ft(g, : f\([ l/U 4444444444444f44444444444f444444/ENi/ OF AREA 4444T44444444444t44444444444-H4f •SEMES AfWLYSJS UNITS City of Carlsbad - ThospsDR Property Sewer Analysis DISTANCE OIABETER FLGS ELEVATION AREA FEET INCHES HSJ> FEET ACRES 9/ 9/98 14:56: 5 PAGE I SEIES ANALYSIS LOAD SUBBARY City of Carlsbad - Thoipson Property Sewer Analysis Hanhole Total Contributed Point Area Flow Source 7 11,88 .§8 ,83 10 16,88 M M 13 13.88 .88 .88 16 111.88 .82 .88 25 61.88 .81 .08 31 39.88 .81 .83 37 1.88 .38 M 43 1848.N .23 .83 4'? 18.88 .88 .88 52 23.00 .31 .BB 55 11.28 .88 .38 58 27.88 .31 M 61 31,88 .31 ,88 64 18.88 .88 .88 73 9.88 M J8 73 12.88 .88 .88 76 .38.33 .81 .88 79 5.38 .88 .88 82 24.88 .31 .88 285 5.88 .83 .88 2S9 13.83 .33 ,88 211 69.38 ,82 .83 214 6.88 .88 .88 217 9,88 .38 .88 223 56.88 .81 .88 223 44.88 .01 .80 588 268.88 .36 .83 UJ WARNING W ZERO OR NEGATIVE FLQB IN THIS REACH tW 9/ 9/98 14:56; 3 PASS 2 3E5O ANALYSIS SANITARY LOAD APPLICATIONS City of Carlsbad - Thcspson Property Sewer Analysis M HH Slope Sias Capa- Area Flow Point Average Peak Vel- Depth Under Capacity Up Bonn 388 223 228 217 214 211 283 285 282 A, ' LT T T 533 82 79 76 73 73 223 228 217 214 211 238 235 282 37 32 79 76 73 78 46 m HARMING 133 64 61 58 55 52 49 73 46 64 61 58 55 52 49 46 46 43 .81988 .81908 .32338 .32280 .37388 .85588 .36538 .88128 .82168 .32388 .34533 .36373 ,85158 .37798 .85838 tit ZERO .87333 .36233 .85173 .85583 .34288 .86313 .85238 .33488 8 8 3 8 8 8 3 3 3 3 a 8 8 8 8 OR 8 8 8 3 8 8 3 3 city: 1.16 1.16 1.19 1.27 2,22 1.97 2.14 2.39 1.23 1.19 1.78 2.12 1.91 2.34 2.83 NEGATIVE 2.22 2.13 1,91 1.97 1.74 2.11 1.93 ,53 .33 44.88 56.33 9.88 6.38 69.88 13.88 5.38 .33 268.88 26.83 5.83 38.88 12.88 3.33 FLOS I« .88 13.33 31,33 27.88 11.88 28. U 13.33 .83 Input Source Flos Flow .83 .38 ,83 .33 .81 .88 .81 .83 .81 .38 .82 .36 .88 .88 ,32 .87 .33 .83 .83 .37 .32 .38 .34 .11 .38 .S3 .34 .11 .38 .88 .84 .12 .88 .88 .34 .12 .36 .88 .86 .15 .31 .83 .36 .17 .88 .83 .87 .17 .81 .83 .87 .19 .38 .83 .83 .19 .33 .33 .33 .28 THIS REACH Wi .83 .83 .38 .33 .38 .88 .83 .31 .31 ,88 .81 .83 ,31 ' .88 .31 .84 .38 .88 .82 .85 .81 .83 .82 .86 .88 .§8 .83 .37 .1 .88 .38 .18 .26 ocity Ratio Replace Relief identification .3 2,1 2.6 2.8 4.3 4.4 4.7 5.3 3.3 3,4 4.8 5.4 5,1 6.8 5.4 .3 2.4 2.9 3.3 3.2 3.3 3.8 2,2 .38 .12 .16 .16 .13 .16 .16 .16 .22 .25 ,22 .23 .22 .23 .22 .88 .36 .89 .18 .12 .12 .13 .52 $3 48 *,33298 1.52 1048,38 .33 6.5 .54 ' * 9/ 9/93 14;56:17 pfiSE 3 SESER ANALYSIS SANITARY LOAD APPLICATIONS City ef Carlsbad - Tlwspson Property Seser Analysis HH HH Slope Dia» Capa- Area Flos Paint Average Peak Vel- Depth Under Capacity Up Down 43 282 37 34 31 28 25 22 19 16 13 13 7 4 37 37 34 T<01 23 25 22 19 16 13 13 7 4 1 .11790 .85198 .83588 .82388 .33433 .32833 .32263 .82318 .32538 .81§?8 .00348 .31558 .88958 3 3 3 3 3 3 3 3 3 18 13 18 18 city 2.83 1.91 1.57 1.41 1.55 1,19 1.21 1.23 1.33 1.59 1.48 1.98 1.43 Input Source ,38 1.33 .83 39.88 .38 61.33 .38 .33 111.38 13.88 16.33 11.38 M M M M ,81 .38 .81 .33 .83 ,82 .38 .38 .33 .33 .88 .33 .33 .83 .38 .38 .38 .33 .38 .88 .38 .38 .33 FlON .33 .8 .38 .38 .39 ,39 .43 .43 .43 .42 .43 .43 .43 .43 Flow ,79 ,39 .89 .91 .91 ,94 .94 .94 1.33 1.38 1.01 1.82 1.82 AREA t ocity Ratio Replace Relief Identification 18.2 7,9 6.8. 4.3 6.3 5,5 5.6 5.3 6.1 4.5 4.1 5.2 4.3 .37 f .53 .57 .62 .53 .71 .73 .67 .68 .68 .66 .54 .64