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Home My WebLink AboutCOM 0407.001 2018-2020Aaron S Y. Chung Chair Hawai `i County Council Council Member District 2 Phone No.: (808) 961-8272 Fax No.: (808) 961-8912 aaron.chung@hawaiicounty.gov HAWAII COUNTY COUNCIL County of Hawai `i Hawai `i County Building 25 Aupuni Street Hilo, Hawai `i 96720 DATE: September 4 2019 too!) TO: Council Members Hawai `i County Council FROM: °baron S. Y. Chun g RE: Resolution 253-19 I have just received an email from the Department of Public Works regarding the above - referenced resolution. Please see attached abstract for the 2010 United States Geological Survey (USGS) regarding Flood -Frequency Estimates for the State of Hawaii. Please note that the 130 - page report itself is not included. ASYC:awm cc: L. Murashige comms No. 1407, Ref. To: Ref, Date .SEP A d 20t9' Hawai `i County Is An Equal Opportunity Provider And Employer Flood -Frequency Estimates for Streams on Kaua'i, O'ahu, Moloka'i, Maui, and Hawai'i, St... Page 1 of 3 acUSGS science for a changing world USGS Home Contact USGS Search USGS U.S. Geological Survey Scientific Investigations Report 2010-5035 " , - - '> SIR 2010-5035 Prepared in cooperation with the State of Hawaii Department of Transportation Flood -Frequency Estimates for Streams on Kauai, Oahu, Molokai, Maui, and Hawaii, State of Hawaii By Delwyn S. Oki, Sarah N. Rosa, and Chiu W. Yeung ABSTRACT Regional regression equations were developed for peak discharges with 2-, 5-, 10-, 25-, 50-, 100-, and 500 -year recurrence intervals for unregulated streams (those for which peak discharges are not affected to a large extent by upstream reservoirs, dams, diversions, or other structures) in areas with less than 20 percent combined medium- and high-intensity development on Kauai, Oahu, Molokai, Maui, and Hawaii. The generalized -least-squares (GLS) regression equations relate peak stream discharge to quantified basin characteristics (for example, drainage -basin area and mean annual rainfall) that https://pubs-usgs.gov/sir/2010/5035/ Last modified August 11, 2010 First posted June 21, 2010 ■ Report PDF (8.4 MB) ■ Tables 4,, 6, il,, and 12 folder. In addition to being in the report PDF linked above, these four tables are available here as spreadsheets in different formats (4.1 MB total) ■ This report is available only on the Web. ............................................. For additional information contact: Center Director, Pacific Islands Water Science Center U.S. Geological Survey 677 Ala Moana Blvd., Suite 415 Honolulu, HI 96813 htto://hi.water.usos.gov/ 9/4/2019 This study provides an updated analysis of the --�---•��--� magnitude and Fk*d - FrequencV Estimates for Streams on Ksua'c frequency of peak O'afw. M a'i. Maui. and NNWat'►. State of Nawal'i stream discharges in Hawaii. Annual peak - discharge data collected by the U.S. Geological Survey during and before water year 2008 (ending September 30, 2008) at stream-gaging stations were analyzed. ` p'T The existing generalized -skew value for the State of Hawaii was retained, although three methods were used to evaluate whether an update was needed. Regional regression equations were developed for peak discharges with 2-, 5-, 10-, 25-, 50-, 100-, and 500 -year recurrence intervals for unregulated streams (those for which peak discharges are not affected to a large extent by upstream reservoirs, dams, diversions, or other structures) in areas with less than 20 percent combined medium- and high-intensity development on Kauai, Oahu, Molokai, Maui, and Hawaii. The generalized -least-squares (GLS) regression equations relate peak stream discharge to quantified basin characteristics (for example, drainage -basin area and mean annual rainfall) that https://pubs-usgs.gov/sir/2010/5035/ Last modified August 11, 2010 First posted June 21, 2010 ■ Report PDF (8.4 MB) ■ Tables 4,, 6, il,, and 12 folder. In addition to being in the report PDF linked above, these four tables are available here as spreadsheets in different formats (4.1 MB total) ■ This report is available only on the Web. ............................................. For additional information contact: Center Director, Pacific Islands Water Science Center U.S. Geological Survey 677 Ala Moana Blvd., Suite 415 Honolulu, HI 96813 htto://hi.water.usos.gov/ 9/4/2019 Flood -Frequency Estimates for Streams on Kaua'i, O'ahu, Moloka'i, Maui, and Hawai'i, St... Page 2 of 3 were determined using geographic information system (GIS) methods. Each of the islands of Kaua`i3O`ahu, Molokai, Maui, and Hawaii was divided into two regions, generally corresponding to a wet region and a dry region. Unique peak -discharge regression equations were developed for each region. The regression equations developed for this study have standard errors of prediction ranging from 16 to 620 percent. Standard errors of prediction are greatest for regression equations developed for leeward Molokai and southern Hawaii. In general, estimated 100 -year peak discharges from this study are lower than those from previous studies, which may reflect the longer periods of record used in this study. Each regression equation is valid within the range of values of the explanatory variables used to develop the equation. The regression equations were developed using peak -discharge data from streams that are mainly unregulated, and they should not be used to estimate peak discharges in regulated streams. Use of a regression equation beyond its limits will produce peak -discharge estimates with unknown error and should therefore be avoided. Improved estimates of the magnitude and frequency of peak discharges in Hawaii will require continued operation of existing stream - gaging stations and operation of additional gaging stations for areas such as Molokai and Hawaii, where limited stream - gaging data are available. Suggested citation: Part of this report is presented in Portable Document Format (PDF); the latest version of Adobe Reader or similar software is required to view it. Download the latest version of Adobe Reader, free of charge. Oki, D.S., Rosa, S.N., and Yeung, C.W., 2010, Flood -frequency estimates for streams on Kauai, Oahu, Molokai, Maui, and Hawaii, State of Hawaii: U.S. Geological Survey Scientific Investigations Report 2010-5035, 121 p. Contents Abstract Introduction Setting Data Frequency Analysis at Gaged Sites Regression Analysis Application of Regression Equations Comparison with Previous Estimates Summary References Cited one Appendix Accessibility FOIA Privacy Policies and Notices U.S. Department of the Interior I U.S. Geological Survey URL: http:// pubs.usgs.gov/sir/2010/5035/index.html L `'A gov... . https://pubs.usgs.gov/sir/2010/5035/ 9/4/2019 Flood -Frequency Estimates for Streams on Kaua'i, O'ahu, Moloka'i, Maui, and Hawai'i, St... Page 3 of 3 Page Contact Information: USGS Publications Team T•,K PtP 11Dt Page Last Modified: Thursday, 10 -Jan -2013 19:12:29 EST https://pubs.usgs.gov/sir/2010/5035/ 9/4/2019