DEPARTMENT OF LAND AND NATURAL RESOURCES
PETER T. YOUNG, CHAIRPERSON
Phone: (808) 587-0401
Fax: (808) 587-0390
For Immediate Release:
National Dam Inspection Act
The National Dam Inspection Act, Public Law 92-367 authorized the Army Corps of Engineers to inventory and inspect dams in the U.S. This act was Congress's response to a string of dam failures in the country.
Here in Hawaii the Army Corps of Engineers compiled an inventory of dams identifying a one-page description of critical features.
Between 1979-1981, after several more dam failures, additional funding for this Act was provided and the Army Corps of Engineers did more detailed investigations of the dam structures that were classified as having a high downstream hazard potential. Various local consulting firms assisted in this inspection effort and approximately 60 dams were inspected.
Hawaii's Dam Safety Program Budget and Staffing
In June of 1987, the Hawaii Dam Safety Act was passed and HRS 179D was adopted, identifying DLNR as the lead agency. Two years later in 1989 Administrative Rules chapter 190 was drafted.
The Administrative Rules authorized the Board of Land and Natural Resources
to inspect and require reports, require written approval for new dam
construction and alterations (permits), require emergency action plans
for high hazard dams, be authorized to enter private property, require
maintenance and repairs as required.
In 1999 DLNR lost the operational budget to contract out dam inspections and therefore initiated in-house inspections.
Since that time the program has suffered additional state funding reductions and had to rely on Federal Grants to sustain the expenditures within the program. The inventory was last updated in 2002 with minor updates beyond that.
The Engineering Division of the Department of Land and Natural Resources (DLNR) administers the Hawaii Dam Safety Program. Referred to as the Hawaii Dam Safety Act of 1987, it was part of a National Dam Safety movement that began as a result of several large dam failures in the mainland US during the mid-1900s.
Hawaii’s Dam Safety and Flood Control program budget is approximately $164,000 (all but about $2,000 is for salary). In the late-1990s, three positions (Program Engineer, Draftsman and Senior Engineer) were established to deal with Dam Safety and Flood Control.
The staff activities are evenly divided between these two programs: Dam Safety and Flood Control; meaning, the Dam Safety Program has the equivalent of approximately 1.5 FTE.
At the end of June 2005, the Program Engineer retired and the Senior Engineer assumed a temporary assignment as Program Engineer. Since the middle of 2005, the Dam Safety and Flood Control section has had one engineer.
Presently, there is a permanent Program Engineer in place and recruitment for the Senior Engineer position has finalized and the offer to fill the position should be completed soon.
The State Dam Safety Program does not do the construction or repairs to dams; dam owners are responsible for repairs of their dams.
No dam inspections were made during 2005 and early 2006 by DLNR. While Dam Safety and Flood Control activities continued during this time, attention was diverted to tsunami mapping for State Civil Defense and dealing with response to the Manoa floods.
DLNR has requested inspection, maintenance and operations information from all dam owners, so that we make sure that we have a complete record of these activities.
Rules require dam owners to provide for the adequate and timely maintenance, operation, and inspection of their dams and reservoirs and owners shall be responsible for any engineering and geologic investigations which may be required to insure public safety.
DLNR presents periodic dam safety workshops to address some of the operational and maintenance challenges and concerns of owners and operators of dams and reservoirs here in Hawaii.
The last round of workshops was conducted on Oahu, Kauai and Maui in 2002. Among the topics discussed was "various ways embankment dams typically fail" and "symptoms and initial signs of a possible dam failure."
Dam Installation/Modification Permit Process:
Most of the dams in Hawaii were constructed prior to any dam safety regulations being promulgated.
A Dam permit is only required if owners alter, enlarge, remove, construct or improve the dam structure or appurtenant features.
Typically, when someone alters a dam they get a County Building Permit, a Dam Construction/ Alteration Permit, National Pollutant Discharge Elimination System (NPDES) Permitting Program (NPDES) Permit and possibly a Commission on Water Resource Management (CWRM) Stream Channel Alteration Permit. Permitting for dams requires County, State and Federal permits.
Only dams of a certain size (height and volume) criteria are regulated under the Hawaii program. Generally, regulated dams have a dam height over 25 feet and impound more than 5 million gallons of water (some exceptions apply).
Dam owners must operate and maintain their dams in a safe manner to ensure its continued service and integrity as well as reducing the risk to public safety and the environment.
Dam Hazard Classifications
Federal Guidelines for Dam Safety
Common practice among federal and state dam safety offices is to classify a dam according to the potential impact a dam failure (breach) or mis-operation (unscheduled release) would have on upstream and/or downstream areas or at locations remote from the dam.
Three classification levels are adopted as follows: Low, Significant and High, listed in order of increasing adverse incremental consequences. The classification levels build on each other, i.e., the higher order classification levels add to the list of consequences for the lower classification levels.
This hazard potential classification system categorizes dams based on the probable loss of human life and the impacts on economic, environmental, and lifeline interests. Improbable loss of life exists where persons are only temporarily in the potential inundation area.
For instance, this hazard potential classification system does not contemplate the improbable loss of life of the occasional recreational user of the river and downstream lands, passer-by, or non-overnight outdoor user of downstream lands. It should be understood that in any classification system, all possibilities cannot be defined. High usage areas of any type should be considered appropriately.
Judgment and common sense must ultimately be a part of any decision on classification. Further, no allowances for evacuation or other emergency actions by the population should be considered because emergency procedures should not be a substitute for appropriate design, construction, and maintenance of dam structures.
Dam hazard classifications refer to the potential loss of human life or property damage in the area downstream of the dam in event of failure or mis-operation of the dam or appurtenant facilities. It is not related to the present condition of the dam nor its stability.
Dams are classified with a hazard potential depending upon the downstream losses anticipated in event of failure. Hazard potential is not related to the structural integrity of a dam but strictly to the potential for adverse downstream effects if the dam were to fail.
High Hazard: Dams in the highest hazard potential category will be those located where failure will most likely result in the loss of life and cause serious damage to homes, extensive agricultural, industrial and commercial facilities, important public utilities, main highways, or railroads.
Significant Hazard: Significant potential category structures will be located in predominantly rural or agricultural areas where failure may result in the loss of life and damage isolated homes, secondary highways or minor railroads or cause interruption of use or service of relatively important public utilities.
Low Hazard: Dams conforming to criteria for the low hazard potential category generally will be located in rural or agricultural areas where failures may damage farm buildings, limited agricultural land, or township and county roads.
Conclusions of Task Force formed to recommend the Dam Hazard Potential system noted:
1. The proposed Hazard Potential Classification System for Dams provides a clear, simple, concise, and adaptable system to classify the hazard potential for dams.
2. The hazard potential rating does not reflect in any way on the current safety, structural integrity, or flood routing capability of the project water retaining structures.
3. The proposed classification system should be submitted to ICODS
with a recommendation for peer review by ASDSO, USCOLD, ASCE, and the
Canadian Dam Safety Association.
5. The proposed Hazard Potential Classification System should be adopted in lieu of existing numerical and alphabetical systems. This is necessary to eliminate confusion in the dam safety community and to educate the public on the importance of dam safety.
Classifications of Dams in Hawaii
There are 133 dams in DLNR’s Hawaii Inventory of Dams. A majority of dams are on neighbor islands: Kauai has 53 (13 State-owned/40 privately-owned), Oahu has 16 (1 State-owned/15 privately-owned), Maui/Molokai/Lanai have 51 (1 State-owned/50 privately-owned), and Hawaii has 13 (4 State-owned/9 privately-owned).
There are 75 high risk dams in the State, 21 significant risk dams, 20 low risk dams and 17 dams with an undetermined risk.
DLNR Instructing Dam Owners to Inspect Dams and Provide Reports
DLNR has instructed all dam or reservoir owners to immediately inspect and report back to the Department the nature and condition of their dams or reservoirs. In addition to the inspection update, all recent maintenance records and documentation of operations and inspections have been requested.
DLNR also instructed dam or reservoir owners to evaluate, and update if necessary, their emergency preparedness plans, including evaluation of potential downstream impacts should the dam or reservoir breach or partially breach.
Included in the letter are these types of requests:
· to update records of maintenance, operation and inspection activities on their dams and reservoirs;
· to update dam failure inundation maps, indicating downstream improvements that may be affected.
· to provide for the adequate and timely maintenance, operation, engineering and inspection of their dams and reservoirs and shall be responsible for any engineering and geologic investigations which may be required to insure public safety.
· to keep available and in good order records of original construction and any modifications, and shall report to the department their maintenance, operation and engineering activities, including piezometric data collection and geologic investigations.
· to advise the department of any sudden or unprecedented flood or unusual or alarming circumstance or occurrence existing or anticipated which may adversely affect the dam or reservoir.
Should an owner decide to remove a dam or reservoir, DLNR has offered to assist a property owner with the permit process and present the request to the BLNR or CWRM for action, as appropriate.
The USGS Pacific Islands Water Science Center is working with DLNR and Hawaii State Civil Defense to assist with the following:
1. Installation of radio-equipped water-level gages on reservoirs where overtopping is a concern. They have ordered equipment from the mainland, which should arrive on Kauai today or Saturday. USGS is planning to work over the weekend so that they can install the equipment as soon as the decision is made one where the gages are to be located. The decision will be made at the local level on Kauai. USGS should be able to install up to 4 gages by the end of next week.
2. Monitoring of dam structural integrity using laser (LIDAR) equipment. The equipment and trained personnel from USGS’s California center should be on Kauai soon.
LIDAR is an acronym for LIght Detection And Ranging. LIDAR is the technology of using pulses of laser light striking the surfaces of the earth and measuring the time of pulse return. LIDAR can measure distance, speed, rotation and chemical composition and concentration of a remote target where the target can be a clearly defined object. (In this case, it will measure any changes of a dam surface.)
3. Hydrologic and hydraulic assessment of the Ka Loko dam break flood:
· Document the distribution of rainfall in the area prior to
and during the event.
USGS headquarters has provided some funding from the national flood reserve to offset some costs of a hydrologic/hydraulic assessment and the local USGS office has some federal matching funds available. The State is expected to reimburse some of the USGS costs.
· Ka Loko Reservoir near Kilauea
All data will be displayed on our public web page at:
Assistance from Army Corps of Engineers
DLNR Engineers are teaming with engineers from the Army Corps of Engineers (Army Corps); these teams are inspecting all dams and reservoirs on the island of Kauai.
After inspections of the Kauai dams and reservoirs are completed, DLNR and Army Corps engineers will conduct inspections of all other dams and reservoirs statewide.
BLNR Takes Emergency Action To Mitigate Flood Damage Potential
The Board of Land and Natural Resources (BLNR) held an emergency meeting on March 16, 2006, to authorize the Department of the Attorney General and its agents, employees, consultants, and investigators, to enter upon private property for the purposes of investigating and inspecting dams and reservoirs located within the County of Kauai pursuant to Hawaii Revised Statutes Chapter 179D.
The Board unanimously approved the emergency measure.
Per HRS chapter 179D, the board maintains authority over dams and reservoirs, including dams and reservoirs located on private property. Kaloko Dam and Morita Dam, located on the island of Kauai, are dams as that term is used in Haw. Rev. Stat. chapter 179D.