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Home My WebLink AboutCT 99-09; Rancho Carrillo Village N; Tentative Map (CT) (12)08/06/1999 10:33 7604382443 ~ " " o HOFMAN PLANNINGo Hofman Planning Associates PAGE 01 \ FAX Transmittal Planning Project Management Rscal Analysis Date: Project: FAX: No. Pages: 3 Attention: Anne Hysong August 6, 1999 D.R. Horton - Rancho Carrillo Village N If all pages are not received, please call {760) 438-1465. Message: Anne, Here is a letter from RECON explaining the analysis to achieve the 60 CNEL standard along Melrose Drive for Rancho Carrillo's Village N. Please call me if you have any questions or need further information. From:Patrick Zabrocki 5900 Pasteur Court • Sle 150 • Carlsbad • CA • 92008 • 760-438-1465 * Fax 760-438-2443 08/06/1999 10:33 7604382443 HOFMAN PLANNING PAGE 02 O My 27, 1999 Mr- Stefan LaCasse D.R. Horton San Diego 1010 South Coast Highway 101, Suite 101 Encinitas,CA 92024-5002 Reference: Noise Analysis forRancho Canillo Village N (RECON Number 3161N) 4241 Jutland Drive, Suite 201 San Oiego.CA 92117-3653 619/270-5066 fax 270-5414 Dear Mr. LaCasse: As requested by Troy Burns of Hunsakcr & Associates, t have reviewed the proposed grading and sound barriers shown on the revised Rancho CarriUo Village N Tentative Map dated May 24, 1999. The original goal of this review was to assess whether including the effects of the northern entrance wall in the analysis would reduce the seven-foot noise barrier height specified for Pad 23 in the acoustical report originally prepared for the property (RECON 1999). This entrance wall was not included in the original analysis. Additionally, the proposed noise barriers shown on the current tentative map were modeled to assess the effects resulting from differences between the barriers specified in the original analysis and those shown on the current tentative map. The current tentative map shows a six-foot-high wall on a one-foot-high berra (total barrier height of seven feet) for the pads adjacent to Melrose Drive (Pads 1 through 6), This agrees with the total barrier height of seven feet specified in the original acoustical report for these pads. A barrier height varying from five to six feet is shown for the pads along the northern project boundary (Pads 21 through 23). The original acoustical analysis specified a barrier height of seven feet for Pad 23, with the remaining barrier heights varying from four to six feet. Additionally, the original acoustical report specified a four-foot-high noise barrier for Pad 20. No noise barrier is indicated tor Pad 20 on the current tentative map. The height of the northern entrance wall was assumed to be six feet per a conversation with Troy Burns. Additionally, all pad elevations have increased slightly relative to Ihose used in the original analysis. As indicated in the acoustical analysis originally prepared lor the property (RECON 1999), it is a policy of the City of Carlsbad to discourage the use of noise walls in excess of six feet in height adjacent to circulation element roadways. With the proposed grading shown on the current tentative map, barrier heights in excess of six feet would still be required to reduce noise levels adjacent to Mclrose Drive (Pads 1 through 6) to 60 community noise equivalent level (CNEL), which is the City's exterior noise standard for residential properties. As with the previous analysis, for those pads immediately adjacent to Melrose Drive, the acceptable exterior noise level (with a condition for notification of future purchasers) was assumed to be 65 CNEL (RECON 1999). The City's 60 CNEL exterior noise standard was assumed for the pads on the northern property boundary. Results of this noise assessment indicate that noise levels for the pads adjacent to Melrose Drive will remain below 65 CNEL with the proposed noise barriers shown on the current tentative map. Noise levels along the northern project boundary will be at or below the City's 60 CNEL exterior noise standard except at Pad 23, Limiting the total noise barrier height to six feet at this pad as shown on the current tentative map will result in a projected exterior noise level of 61 CNEL at that location. 08/06/1999 10:33 7604382443 HOFMAN PLANNING PAGE 03 Mr. Stefan LaCassc Page 2 July 27.1999 This assessment indicates that the proposed northern entrance wall has little if any effect on the noise levels at Pad 23. A seven-foot-high barrier is required to achieve the 60 CNEL standard « Pad 23 as^ was concluded in the prior acoustical report (RECON 1999). In conclusion, with the exception of the barrier indicated for Pad 23, all noise barriers shown on the current tentative map will adequately reduce the projected exterior noise levels to the levels specified in the original acoustical report. A seven- foot-high noise barrier is required for Pad 23. No noise barrier is required for Pad 20. ...... "*"* Patrick Zabrocki of Hofman Planning Associates has subsequently requested that an analysis be performed to determine the required barrier heights to achieve the 60 CNEL exterior noise standard for the pads adjacent to Melrose Drive. Results of this analysts indicate that a total barrier height of K) feet is required to reduce the projected exterior noise levels on Pads 1 through 6 to 60 CNEL. This barrier height is relative to the final pad elevations and may be achieved through a bemV wall combination (e.g.. a six-foot-high wall on a four-foot-high berm). """ If I can answer any additional questions, please call Sincerely, David Gottfredson Acoustician DMG:sh cc: Troy Bums, Hunsaker & Associates Patrick Zabrocki, Hofman Planning Associates Reference Cited RECON 1999 Noise Technical Report for Rancho Carrillo Village N, City of Carlsbad, California. RECON Number 3 161N. May 12.