USACE Participation in High Hazard Dam Evaluations in Hawaii Following the 2006 Kaloko Dam Failure

USACE Participation in High Hazard Dam Evaluations in Hawaii Following the 2006 Kaloko Dam Failure Michael F. Wong, PE USACE Honolulu District September 2016 Alexander Res, Kauai

Inventory/Chronology 135 (132) Regulated Dams in Hawaii. ( 25 ft in height and 50 acre-ft) 1972 Federal Dam Inspection Act (PL 92-367). 1978-1981 Phase 1 inspections conducted by USACE on 52 highhazard dams. 1987 Hawaii Revised Statutes 179D aka Hawaii Dam Safety Act. 14 Mar 06 Kaloko Dam failure on Kauai. March 2006 Inspections (PL 84-99). USACE inspected 54 dams on Kauai at 100% Federal cost. April 2006 Inspections (Interagency and International Services). USACE inspected 83 dams on Hawaii, Oahu, Maui, and Molokai. Also reinspected 4 dams on Kauai. 100% State cost. 15 Oct 06 M6.7 earthquake with M6.0 aftershocks. October 2006 Initial Inspections on Hawaii and Maui by UH, consultants, and Bureau of Reclamation. Oct/Nov 2006 Inspections (Stafford Act). USACE inspected 86 dams on Hawaii, Kauai, Maui, Molokai, and Oahu at 100% FEMA cost. 2

Dams in Hawaii Constructed during Plantation Era for Irrigation Water Storage. Most privately owned. Wahikuli Res, Maui 3

March 14, 2006 Kaloko Dam Failure On March 14, 2006, at about 5 a.m. the privately-owned Kaloko dam failed. Kaloko dam was not one of the dams inspected between 1978 and 1981 as it was not considered high-hazard at the time. 400 MG of water rushed d/s over Morita Dam, through homes, and finally reaching the ocean. 7 people killed. 44 ft 1,400 acre-ft Kaloko Dam, Kauai dimensions 4

Inspections as a Result of the March 2006 the Corps of Engineers, under the authority of PL 84-99 Emergency Flood Protection Act of 1965 conducted visual condition surveys of 54 dams on Kauai. April 2006 the Corps of Engineers assisted the State of Hawaii under the IIS program, conducted visual condition surveys of 83 dams on Oahu, Maui, Molokai, and Big Island to assess if there were any immediate threats to the public. Kaloko Dam Failure Kaloko Dam, Kauai March 2006 5

October 15, 2006 Earthquake October 15, 2006, Hawaii experienced a M6.7 earthquake with aftershocks as great as M6.0. Estimates now at $200M damage to public buildings, roadways, churches, landslides, schools, and homes mostly on the Big Island and Maui. Hwy 19 (outside of Hilo), Hawaii (photo Honolulu Advertiser) 6

Dam Inspections as a Result of October 2006, the State of Hawaii, along with the University of Hawaii, Bureau of Reclamation, Natural Resources Conservation Service, and Corps of Engineers under various authorities conducted visual condition surveys of 135 high-hazard dams throughout the State. 9 GT dam safety personnel from Buffalo, SF, Sacramento, Philadelphia, Louisville, ERDC, Albuquerque, and Honolulu Districts. the Earthquake 7

Dam Inspections as a Result of the Earthquake 86 dams inspected throughout the State under the Stafford Act (100% Federal funding) by USACE between 30 Oct 8 Nov 06. No definitive earthquake damage found on Oahu, Kauai, and Molokai. Some damage found on the Big Island and Maui dams. Generally, findings the same as the March/April 2006 inspections. Paauilo Reservoir, Hawaii crack in perimeter of dam 8

Inspection Procedure & Documentation Assistance requested by State Dept of Land & Natural Resources (DLNR). Assemble team; deployment of Corps of Engineers Dam Safety Personnel. Schedule inspection dates/times with dam owners. Preparatory meeting including safety brief. Review of existing information. Fill in State DLNR Inspection Form. Quality control of inspection data. 9

Inspection Procedure & Documentation Immediate notification of DLNR if major problem exists. Inspector completion of report and photo record in the office. QA check by the PM. Compilation and advance transmittal to the DLNR. Official transmittal to the DLNR and State Civil Defense. State in turn notifies each dam owner of the inspection findings and requests response from owner on remedy and schedule. 10

Typical Findings Vegetation overgrowth on all features of the dam. Large trees on dam structure. Unimproved or lack of spillway. Inoperable outlets. Sloughing of reservoir sides. Erosion on dam face or abutments. No staff gage. Seepage in dam or abutment. No documentation on the dam. Abandoned dams can still impound water. 11

Findings Opaeula 15, Oahu - localized slide Lalakea Reservoir, Hawaii d/s slope heavily vegetated 12

Findings Opaeula 2 Res, Oahu - slope heavily vegetated Alexander Res, Kauai rockslide in abutment 13

Findings Opaeula 2 Res, Oahu panoramic view of deep soil erosion from a spillway overflow gate 14

Findings Opaeula 2 Res, Oahu the downstream toe is wet (at full reservoir level) and a bubbling sound could be heard, but no flow of water was observed. Continue monitoring. 15

Findings Opaeula 1 Res, Oahu a tunnel (spillway) collapse 16

Earthquake Damage? 86 dams inspected 13 on Hawaii 52 on Kauai (Kaloko dam not inspected) 16 on Oahu 4 on Maui (reinspected those dams that Bureau of Reclamation found damage) 1 on Molokai 7 appear to have damage caused by the earthquake Waikoloa 50 MG Res 1, Hawaii boils at toe 17

Exposed liner Crack occurring at the limit of the liner liner Earthquake generated crack Embankment Paauilo Res, Hawaii half inch wide crack with the liner exposed inside the crack. The cracks are likely occurring at the limit of the liner on the crest of the embankment. 18

Earthquake Damage? Waikoloa 50 MG Res 2, Hawaii cracks in crest Puu Kapu Reservoir, Hawaii rip rap slide 19

Earthquake Damage? Kehalani Offsite Ret Basin, Maui slope failure Hanakaoo Res, Maui movement in crest 20

Earthquake Damage? Kumano Reservoir, Kauai rock wall collapse 21

Follow-on Dam Break Studies $2M provided by Congress in the FY06 Emergency Supplemental Appropriation to conduct dam break analyses of selected dams. Purpose is to establish the downstream inundation area under various dam failure scenarios. Hydrologic and hydraulic studies; no structural or geotechnical investigations. Corps of Engineers Dam Break Training January 2007 22

Follow-on Dam Break Studies 7 dams on Kauai, 1 dam on Maui, 1 dam on Molokai, and 2 dams on Oahu will be studied. Work includes: hydrologic studies; various dam failure scenarios; hydraulic analysis; preparation of detailed downstream hazard inundation maps. Maps to be used to develop emergency action plans including warning systems. Complete studies in 1 year time frame Common methodology Technical Advisory Group Training by HEC Identify potential beak directions and inundation areas Data gaps -Topographic data IFSAR data; limited use LIDAR data contract Aerial and satellite imagery GPS and ground survey 24

Dam Safety Experts Ray Kong, Honolulu Henri Mulder, Sacramento Rick Britzman, Sacramento Pat Fitzgerald, Alaska Jerry Raychel, Alaska Dwayne Lillard, Albuquerque Art Maestas, Albuquerque Dr. Joe Koester, ERDC Troy Cosgrove, Philadelphia Troy O Neal, Louisville Bill Empson, Kansas City John Dillon, Kansas City Jon Kolber, Buffalo Ken Harrington, San Francisco Tim O Leary, Louisville Dr. Rick Olsen, ERDC Bruce Rogers, Philadelphia Assistance and support from State agencies, NRCS, counties, and dam owner reps. 25

DAM BREAK ANALYSES TEAM USACE, Honolulu State of Hawaii, DLNR USACE, HEC USACE, Rock Island PB Americas & Northwest Hydraulic Consultants SSFM & WEST Consultants Tetra Tech Oceanit Upper Helemano Reservoir, Oahu 26

Follow-on Dam Break Studies Dams Studied: Kauai Twin, Waita, Elua, Puu Lua, Aepo, Halamanu Field 21, and Upper Kapahi reservoirs Oahu Nuuanu and Wahiawa reservoirs Maui Reservoir 24 Molokai Kualapuu reservoir 27