In addition to the terms defined by 85-15-105, MCA, the following definitions apply in this subchapter, unless the context requires and clearly states otherwise.

(1) "Act" means the Montana Dam Safety Act, Title 85, Chapter 15, MCA.

(2) "Breach flooded area" means the area downstream from a dam that would be inundated if the dam failed.

(3) "Commence construction" means the actual start of site preparation and on-site building, but does not include preliminary surveying work, site exploration, or engineering plans preparation.

(4) "Construction permit" means a written authorization issued by the department giving the owner authorization to construct a dam or reservoir in accordance with conditions that ensure construction of the dam and reservoir in a thorough, secure, and substantial manner.

(5) "Corps" means United States Army Corps of Engineers.

(6) "Days" means calendar days, including Sundays and holidays. If the final day in a time calculation falls on a holiday or weekend, the day shall be the next succeeding regular business day.

(7) "Department" means the Department of Natural Resources and Conservation and any of its employees, agents, or designees authorized by the director of the department to act on behalf of the department.

(8) "Emergency procedures and warning plan" means a predetermined plan of action to be taken to reduce the potential for property damage and loss of lives in an area affected by a dam break.

(9) "Height of dam" means the vertical distance from the lowest elevation of the dam crest to the lowest point of natural ground, including any stream channelalong the downstream toe of the dam.

(10) "Inundation" means water, regardless of depth, over the general level of the submerged ground adjacent to and including the stream channel.

(11) "Loss of life" means loss of human life.

(12) "Maximum normal operating pool":

(a) means the elevation of lowest uncontrolled principal spillway for on-stream reservoirs;

(b) means the elevation of the emergency spillway for flood control structures; and

(c) is defined on a case-by-case basis according to reservoir operation for off-stream reservoirs.

(13) "Operating permit" means a permit issued by the department for a period not to exceed five years to operate a high-hazard dam or reservoir.

(14) "Operation plan" means the written instructions prepared by the owner that prescribe:

(a) proper operation procedures;

(b) maintenance procedures;

(c) emergency procedures and warning plan; and

(d) any other features necessary to the safe operation of the dam or reservoir.

(15) "Permit" means construction or operation permit.

This rule has been repealed.

This rule has been repealed.

(a) violation of any permit condition;

(b) failure to fully disclose all relevant facts or obtaining a permit through misrepresentation;

(c) violation of the act or these rules; or

(d) change or newly discovered condition or circumstance that makes or would make the dam unsafe.

This rule has been repealed.

(1) An application for hazard determination must be made by an owner proposing to construct, including new construction, alteration, repair, enlargement, or removal of, any dam or reservoir that has or could impound to the maximum normal operating pool 50 acre-feet or more.

(a) Dams already classified as high-hazard are not required to reapply for a hazard determination.

(2) Applications for hazard determinations are not necessary for the following, as loss of life from dam failure is not likely to occur:

(a) wastewater pond dams that are subject to regulation under the Department of Environmental Quality (DEQ) and will be constructed according to DEQ regulations;

(b) naturally occurring reservoirs;

(c) an obstruction in a canal used to raise or lower water inside the canal, or to divert water from the canal;

(d) a flood levee on the bank of a natural lake or stream, the primary purpose of which is to control floodwaters;

(e) railroad fill structure and road or highway fill not intended to store or accumulate water for future use; and

(f) an obstruction in the channel of a stream, watercourse, or floodplain, which has the single purpose of spreading water within the bed of the stream or watercourse or floodplain upstream from the obstruction for irrigation of only that land containing the spread water.

(1) A single application may be submitted for more than one dam when the dams are:

(a) for the same reservoir or in series; and

(b) would flood the same drainage if failure should occur.

(1) An application for hazard determination must be submitted to the department.

(2) An application must be made on a form provided by the department and must contain at least the following:

(a) name, address, and phone number of the owner;

(b) reservoir and dam general description to include not less than the impoundment capacity, dam height, location, and purpose;

(c) maps showing the location of the proposed structure;

(d) signature of owner or owner's authorized representative and date of the signature; and

(e) an inspection fee of $125.

(3) Consideration of each alternative dam height and storage capability must be submitted in an additional application containing all relevant information for the alternative.

(a) notify the owner in writing within 10 days of receipt that an application has been received and advise the owner of any additional information required to complete the application;

(b) arrange for a field investigation with the dam owner to gather data or information to make a hazard determination;

(c) classify the hazard of the dam or reservoir based on the application, the site inspection, and evaluation of the potential flooded area caused by a dam failure; and

(d) notify the owner in writing of the hazard classification determination within 60 days of receipt of a complete application.

(2) A dam must be classified high-hazard if the impoundment capacity is 50 acre-feet or larger measured at the maximum normal operating pool, and it is determined that a loss of human life is likely to occur within the breach flooded area as a result of failure of the dam.

(a) Loss of life is assumed likely to occur if the following structures are present or planned for as a matter of public record or notice in the breach flooded area:

(i) occupied houses and farm buildings;

(ii) stores;

(iii) gas stations;

(iv) parks;

(v) golf courses;

(vi) stadiums;

(vii) ball parks; and

(viii) interstate, principal, and other paved highways, including railroads, highway rest areas, RV areas, and developed campgrounds. Excluded from this list are unpaved county roads and all private roads.

(3) For purposes of the hazard determination classification in this section, the following apply.

(a) The breach flooded area is the flooded area caused by a breach of the dam with the reservoir full to the maximum normal operating pool.

(b) The evaluation of the effects of flood inundation will continue downstream until the flood stage is equal to that of the 100-year floodplain.

(c) The breach flow hydrograph and downstream routing of the breach flows will be estimated by the department either by visual determination or dam breach modeling techniques.

(1) A high-hazard dam owner may request the department to reconsider a hazard determination.

(a) A request for reconsideration must include the data and analyses necessary to show that the dam is not a high-hazard dam.

(b) The owner shall pay for reasonable inspection costs incurred by the department as a result of the reconsideration.

(2) A classification of high-hazard dam is automatically rescinded if the dam is constructed to impound less than 50 acre-feet measured to the maximum normal operating pool, or if the dam is breached.

(a) A construction permit is necessary to perform the construction to reduce the impoundment capacity of the high-hazard dam or breach the high-hazard dam.

(1) The worst case scenario shall govern for determining the hazard classification of dams in series where more than one mode of failure is possible among the dams. Classification shall be based on potential for failure under combined and, if applicable, individual dam breach scenarios.

(2) The upstream dam must be classified as a high-hazard dam if:

(a) an upstream dam has the capability to create failure in a downstream high-hazard dam because of its failure flood wave; or

(b) the failure flood wave of the upstream dam will likely cause a loss of life, with or without failure of the downstream dam.

(3) Wastewater ponds that are separated by internal berms are not considered to be dams in series.

(2) Reservoir capacity due to excavation in the impoundment area is excluded from capacity calculations.

(3) This rule applies to multiple or a series of dams erected on a valley, basin, coulee, or ravine where each reservoir is less than 50 acre-feet, but all are operated singly as one reservoir containing more than 50 acre-feet. Whether the series is operated as a single reservoir will be a question of fact in each instance. Factors to consider include:

(a) whether all dams or reservoirs are under the same ownership and control;

(b) whether all dams or reservoirs operate as a unit (i.e., if one of the dams or reservoirs suffers a change, it will in most instances affect one or more of the other dams or reservoirs); or

(c) whether the dams or reservoirs are physically proximate and on the same valley, basin, coulee, or ravine.

(1) An owner who wishes to construct, alter, repair, enlarge, or remove a high-hazard dam shall apply for, and receive from the department a construction permit prior to any construction.

(2) A single application must be submitted for each dam, even if the dams are part of a single project or facility.

(3) An application for a construction permit must include:

(a) the engineering design report;

(b) the construction plans and specifications; and

(c) the application form provided by the department. The application form must:

(i) be signed by the owners of the dam or reservoir;

(ii) include the name, address, and phone number of the owner; and

(iii) include the name and purpose of the proposed dam or reservoir.

(4) The construction plans and specifications and engineering report must be prepared by or under the supervision of an engineer experienced in dam design and construction and shall be certified with the seal of the engineer.

(5) Within 30 days after receipt of the application, the department shall notify the applicant of any errors or omissions and request any additional information necessary to properly evaluate the application. The department may disapprove any application for failure to promptly submit the required information.

(6) The department shall issue a construction permit if the design and construction as proposed conforms to the design and construction criteria specified in these rules and to accepted practices and procedures of the engineering profession.

(1) The owner shall pay for the department's actual and necessary costs, excluding salary and travel expenses, incurred for occasional inspections during construction if a need arises from a particular circumstance to ensure a safe dam.

(2) The cost must be paid within 30 days of billing by the department.

(3) Failure to pay the costs billed within 30 days of mailing by the department will result in the automatic cancellation of the construction permit and a forfeiture of all rights acquired under the permit.

(1) An engineering design report for construction of a new dam must include:

(a) a summary describing:

(i) the name of the proposed dam;

(ii) the name of the engineer;

(iii) the mailing address of the engineer;

(iv) the location of the proposed dam;

(v) the type, size, and height of the proposed dam;

(vi) the storage capacity and reservoir surface area for normal and maximum water surface elevation;

(vii) a general description of the dam and appurtenances;

(viii) maps showing the location of the structure that include county and state roads, and access to the site and the outline of the reservoir (Aerial photographs or USGS maps may be used) ;

(ix) an outlet discharge capacity rating table(s) referenced to reservoir elevations indicating the discharge that can be safely released;

(x) a rating table(s) indicating spillway discharge capacity referenced to reservoir elevations;

(xi) a table showing the reservoir area (in acres) and storage capacity (in acre-feet) for each foot of elevation from zero storage to the crest of the dam (Indicate the elevation of the dead storage, outlet elevation, and the elevation of the spillway(s) . All elevations shall be given in feet above mean sea level) ; and

(xii) photographs of the proposed site;

(b) a geology report giving a summary of the geological factors of the local area and dam foundation and the reservoir site, including:

(i) faults and fault history that may affect the dam or reservoir site;

(ii) seismicity of area and region; and

(iii) evaluation of reservoir perimeter for slide potential;

(c) a geotechnical report describing the investigation and evaluation and design of the foundation, abutments, embankment of the dam, and the borrow materials. Include an analysis to indicate that the dam, spillway, and appurtenances will be stable during construction, filling, and under all conditions of reservoir operations, including design earthquake loading;

(d) a hydrologic and hydraulic report that gives the design procedure(s) , calculations, and data for the reservoir and appurtenances;

(e) a drainage design report describing the data and evaluation of the seepage expected and the drainage and instrumentation design. The report must include criteria, design data, and references to show that seepage flow through the embankment, foundation, abutments, and appurtenant structures will be monitored and controlled so that no internal erosion will take place and so there will be no sloughing in the area where the seepage emerges;

(f) a quality control plan describing the extent and nature of the quality control during the proposed construction. The plan must include the responsibilities of the owner and engineer, the frequency of inspection, and any other items not already stated in the construction plans and specifications that are necessary to ensure compliance with the approved plans and specifications and construction of a safe dam;

(g) a plan for monitoring the performance of the dam. The plan must describe the assumptions, design considerations, and the proposed construction for the aspects of the dam to be monitored; and

(h) a report of other design data, assumptions, and

analysis data pertinent to individual dams and site conditions.

(1) The construction permit application for the construction of a new dam must be made on plan sheets no larger than 24 x 36 inches or smaller than 21 x 30 inches. Construction details on the plans should be sufficiently complete to accurately lay out the structure and build it.

(2) The plans must be detailed illustrations that include as a minimum the following:

(a) a cover sheet indicating the name of the project, index of drawings, designated access to the project, and the location with respect to highways, roads, and streams;

(b) certifications by the engineer and the owner must be placed on the title sheet (first sheet) of the drawings. The certifications must be similar to those presented in examples 1 and 2.

(i) EXAMPLE 1

Certification by Engineer

I hereby certify that these plans for the (insert the correct word or words choosing from: construction of the; repair of the; enlargement of the; alteration of the; or removal of the)                                                  Dam were

                     Name of Dam

prepared by me (or under my direct supervision) for the owners thereof.

(                ENGINEER'S   )                                                                                                            

(                                           )                                                     Firm Name

(                  SEAL              )                                                                                                             

(                                           )                                                     Engineer

(ii) EXAMPLE 2

                   Certification by Owner

I,                                                                                                             , owner, whose

                                         Name of Owner

Post Office Address is,                                                                                                      ,

                                                      Owner's Address,

Zip                               , do hereby accept and approve these plans and will cause the dam to be constructed pursuant to these plans and specifications and any authorized changes.

                                                                      Owner

(c)site maps that include but are not limited to:

(i) plan view of site including embankment, and emergency spillway;

(ii) topography of structure site including all topographic features;

(iii) land ownership;

(iv) base lines;

(v) center line of embankment and emergency spillway;

(vi) property lines and fence lines;

(vii) construction limits;

(viii) utility lines and pipelines;

(ix) roads, highways, and railroads (with names) ;

(x) bench marks to mean sea level;

(xi) borrow areas and waste areas;

(xii) clearing and grubbing areas;

(xiii) waterways, diversions, and channel improvements;

(xiv) wells;

(xv) fence removal and construction;

(xvi) scale and north arrow;

(xvii) location of springs, seeps, underground mines, mine drainage and openings, the sub drain system; and

(xviii) project stationing, cross-sections, borings and test pits, instrumentation, reference points and other pertinent data shall be included;

(d) a profile along the dam axis and borrow area showing the locations, elevations, and depths of borings or test pits, including logs of bore hole(s) and test pits;

(e) a maximum cross-section of the dam showing elevation and width of crest, slopes of upstream and downstream faces, thickness of riprap, zoning of earth embankment, location of internal drains and filters, core trenches, elevation size and type of outlet conduit, valves, operating mechanism, and dimensions of all other essential structural elements;

(f) details of the outlet works. This should include the intake structure, the gate system, drawings that show conduit details, the trash rack, and the downstream outlet structure;

(g) plan, profile, and control section of all the spillways, including details of any concrete work, complex control structures, concrete chutes, or energy dissipating devices;

(h) drawings showing sub drains, anti-seep mechanisms, and other pertinent structures;

(i) foundation plan showing limits of excavation, construction keying the dam to the foundation and the abutments, and construction to control seepage:

(j) details of diversion scheme if applicable;

(k) location and types of instrumentation of drainage and/or seepage control facilities; and

(l) other drawings, schedules, and notes required for construction and technical review of appurtenant structures.

(2) The specifications must include the following provisions:

(a) the technical provisions describing the method of construction and quality control for the project including, at a minimum, the following:

(i) clearing and grubbing and other site preparation;

(ii) foundation preparation and construction requirements;

(iii) spreading and compaction requirements to include lift thicknesses, moisture content, and degree of compaction with appropriate compaction curves, slopes, and grades;

(iv) material and gradation and construction requirements for filters and drains;

(v) material and installation requirements for pipes and fittings;

(vi) material and placement requirements for concrete;

(vii) installation of monitoring devices;

(viii) revegetation and permanent erosion control, including slope protection;

(ix) public safety;

(x) construction erosion and sediment control; and

(xi) material and installation requirements for equipment;

(b) general provisions that specify the rights, duties and responsibilities of the owner, engineer, builder, and the prescribed order of work;

(c) provisions for adequate observation and inspection by the engineer during construction;

(d) provisions that the plans and specifications must not be materially changed without prior written approval of the engineer;

(e) provisions that certain stages of construction must not proceed without the engineer's approval. Those stages requiring approval are:

(i) after clearing and excavation of foundation and prior to placing any fill material;

(ii) after installation of outlet conduit and before placing any backfill material around conduit;

(iii) after construction is completed and before any water is stored in reservoir; and

(iv) at such other times as determined necessary by the engineer;

(f) provisions that all materials and workmanship must be subject to inspection, examination, and test by the engineer at any and all times during manufacture or construction, and at any and all places where such manufacture or construction are carried on;

(g) provisions that allow the owner or engineer to reject defective material and workmanship and require its correction or replacement with proper material; and

(h) Provisions that the engineer may suspend any work that may be subject to damage by weather conditions.

(a) engineering design report - The report must address and provide specific information pertaining to the following as appropriate or as specified by the department:

(i) a summary, including those items in ARM 36.14.303 (1) , and a general description of the proposed work, and for repair must include the specific measures to be taken to reasonably ensure the problem will not recur or the solution is the most reasonable and will not impact the safety of the dam;

(ii) appropriate geotechnical, hydrologic, and hydraulic calculations and assumptions relative to design of repairs, enlargement, or alteration of the dam or its appurtenances;

(iii) calculations and assumptions relative to design of repairs, enlargement, or alteration to the structural elements of the dam;

(iv) reservoir operation during the construction, including drawdown and refill schedules; and

(v) seepage control, including complete description of measures taken to protect the integrity of the dam during the construction; and

(b) plans and specifications - Detailed construction plans and specifications must be submitted and must include as a minimum the following:

(i) a cover sheet indicating the name of the project, name of owner, certification by the engineer and the owner pursuant to ARM 36.14.304 (2b) , designated access to the site, and the location with respect to highways, roads, streams, and the dam(s) that are affected by the structure;

(ii) drawings showing appropriate cross section and profile views of the proposed work with center lines and horizontal and vertical control points clearly identified in a sufficiently large scale to clearly indicate the extent and complexity of the work to be performed;

(iii) technical provisions, as may be required, to describe the method of construction and quality control for the proposed work; and

(iv) general provisions that specify the rights, duties, and responsibilities of the owner, engineer, and contractor.

(a) removal of brush or weeds, or cutting of trees, removal of slash from the embankment or spillway, and removal of small stumps is included, provided no deep excavation into the embankment occurs;

(b) repair of erosion gullies or minor rodent damage on the embankment or in the spillway (Large gullies that have already weakened the dam must be repaired in accordance with ARM 36.14.306) ;

(c) surface grading of the embankment crest or spillway to eliminate potholes and provide proper drainage, provided that the freeboard is not reduced; and

(d) placement of additional riprap and bedding on the upstream slope, or in the spillway, in areas that have sustained minor damage. This would involve restoring the original riprap protection and maintaining the original capacity where the damage has not yet resulted in weakening of the dam.

(2) Plans and specifications must include as a minimum the following:

(a) a cover sheet indicating the name of the project, name of owner, certification by the engineer and the owner pursuant to ARM 36.14.304 (2b) , designated access to the site, and the location with respect to highways, roads, and streams;

(b) method of draining the reservoir during removal and statement of the sequence of operations;

(c) method of disposal or stabilization of the sediment;

(d) disposition of the dam materials;

(e) description of the reclamation actions to be applied to the dam and impoundment area; and

(f) means for removal of the dam to prevent future impoundment.

(1) The following are standard terms and conditions included in any approval of a construction permit application for construction:

(a) construction work must be started within one year from date of approval, unless an extension is granted;

(b) the owner shall provide the department evidence that a performance bond has been obtained by the contractor for the completion of construction of the dam in the amount of at least 100% of the estimated cost of the project;

(c) the owner shall engage an engineer to provide engineering services during construction and the engineer shall:

(i) be responsible to determine if and when the actual conditions do not conform to the design, and that the construction was carried out in substantial compliance with the approval plans and specifications;

(ii) submit to the department in writing, 30 days before start of construction:

(A) the estimated time to complete the construction activities; and

(B) the inspection force, independent from the construction contractor, by which quality control will be achieved;

(iii) submit to the department in writing within 10 calendar days of the reporting period construction progress reports during the construction period at intervals of 30 days, or more frequent if specified by the department in the permit or upon order of the department.

(iv) The construction reports must summarize the detailed daily log of all construction operations, including written and photographic records, documenting:

(A) the date, location, and results of tests performed on construction materials;

(B) a narrative of problems encountered during construction and inspection and the manner in which they are resolved; and

(C) the foundation excavation and placement of backfill in the core trench;

(v) have the engineering report, plans, specifications, and all previous construction progress and inspection reports available at the construction site for reference;

(vi) notify the department at least 3 days in advance of material placed in the foundation, cutoff trench, outlet foundation, and any other area requested by the department; and

(vii) conduct a final inspection;

(d) the department may conduct unscheduled and periodic inspections during construction as deemed necessary to ensure that the structure is being built in conformity to the approved plans and specifications and will result in a safe dam. The department inspections do not relieve the owner and/or the engineer in charge of the responsibility of providing adequate inspection of the work;

(e) the department shall be promptly advised of all changes in the approved design, plans, or specifications. There shall be no change in the approved design, plans, or specifications without approval of the engineer. All such approved changes shall be recorded on the complete set of as-built drawings;

(f) the owner shall notify the department of the completion and certify that the work has been performed in accordance with the provisions of the permit. Within 30 days after completion, the owner shall submit written certification by the engineer that the structure has been constructed in conformance with the plans, specifications, and changes. Also within one year of completion, the owner shall submit certification by the engineer that the dam and appurtenances are functioning as designed;

(g) the owner, except for construction involving removal of a dam, shall maintain one set and submit one set to the department of as-built drawings and descriptive matter prepared by the engineer showing and describing the dam or reservoir as actually constructed and any other items that may be of permanent value and have a bearing on the safety and performance of the dam or reservoir;

(h) if a dangerous or emergency condition including but not limited to flood during construction, slope failure, or earthquake develops during construction, the project engineer and owner shall initiate a plan and act to immediately correct the dangerous condition and give notification pursuant to ARM 36.14.702; and

(i) for dams where a low level conduit drain is required or has been included, the drain must remain open and no water shall be stored in the reservoir until approval has been granted by the engineer.

(2) If, after the review, the department determines that the work has not been performed in accordance with the provisions of the permit, the department shall specify the deficient items or necessary work in writing to the owner, who shall cause the work to be completed in conformity with the permit.

(2) If the owner or the surety decides to abandon the project, the owner or the surety shall immediately notify the department in writing and, if during construction, submit suitable plans and render the dam safe.

(1) If at any time during construction of any dam or reservoir the department finds that the work is not being done in accordance with the provisions of the permit, including revisions, it shall give a written notice and order by certified mail or by personal service to the owner.

(2) The notice and order must state the particulars in which the permit is not being or has not been complied with and shall order the immediate compliance.

(3) The department may order that no further work be done

until evidence of compliance has been submitted to the department.

(4) If a permittee fails to comply with the permit after receipt of a notice, the permit is deemed canceled, and all rights acquired under the permit are forfeited.

(5) If, after any inspections, investigations, or examinations, or at any time as the work progresses, it is found by the department that amendments, modifications, or changes are necessary to ensure safety, the department may order the owner to revise the plans and specifications.

(6) If, after any inspections, investigations, or examinations, or at any time as the work progresses, conditions are discovered that will not permit the construction of a safe dam or reservoir, the department shall cancel the permit.

(1) For all high-hazard dams not exempt pursuant to the act and ARM 36.14.103, the department shall require an operation permit and impose such reasonable conditions as are necessary to ensure that high-hazard dams are safely operated and maintained, and that the operation and maintenance of high-hazard dams are consistent with the act and all implementing orders and administrative rules. An application for an operation permit to operate a high-hazard dam must be submitted to the department:

(a) before operation of a high-hazard dam for which a construction permit has been issued; and

(b) by the date specified in the permit for renewal of an operation permit for a permitted high-hazard dam.

(1) Applications, including applications for renewal of a permit to operate high-hazard dams must include:

(a) an operation plan pursuant to ARM 36.14.403; and

(b) notification that an inspection has been completed, except for a new dam for which a construction permit has been issued.

(2) A report of the inspection pursuant to ARM 36.14.603 must be submitted to the department within 90 days of the inspection, before the application can be considered complete. The inspection must be of the dam in its condition and configuration at the time of the application.

(3) Within 30 days of receipt of a permit application, the department shall:

(a) notify the applicant of any errors or omissions, and request any additional information necessary to properly evaluate the application; and

(b) establish a reasonable time frame for the applicant to submit the necessary information.

(4) After receipt of all required information, the department shall issue or deny the permit within 90 days, but not before approval of any construction pursuant to a construction permit.

(a) the operation procedures;

(b) maintenance procedures; and

(c) emergency procedures and warning plan.

(a) procedures for safe drawdown rate of the reservoir;

(b) a description of the capabilities and limitations of the outlet facilities, spillways, and other dam appurtenances;

(c) a description of the authority granted to the dam tender and the training and direction or instruction necessary to properly and safely operate the gates and other dam appurtenances during normal, flood, and emergency conditions;

(d) a description of the availability of the dam tender, means of communication between the dam tender and his supervising authority, and method of gate operation, for example, manual, automatic, or remote control;

(e) a plan to monitor and anticipate unusual weather and hydrologic conditions and incorporate these conditions into the operation plan;

(f) a plan including the method and frequency for routine inspections conducted by an engineer, or owners or dam tender, at least once per year as well as inspections after critical events identified in the plan, for example, during and after heavy runoff, a severe rainstorm, a severe wind storm, or after an earthquake, and during periods of high storage. The plan must identify an inspection checklist and other directions to complete the required inspections. Inspections following critical events must be performed by an engineer, who may also be the owner or the dam tender, experienced in dam inspection. The completed inspection checklist and any other report must be maintained in the owner's records;

(g) a plan for permanent monitoring of the dam, for example, instrument installations, seepage collection systems, and water levels necessary to ensure the safe operation of the dam. The plan must identify the frequency of the data collection and the data value(s) that would constitute an unsafe or watch condition. If no monitoring is considered necessary, the reasons for this judgment must be stated; and

(h) a plan for interaction with operations of other dams and reservoirs, upstream and downstream, that may affect or be affected by the dam or reservoir operations during normal and emergency releases.

(1) Maintenance procedures of the high-hazard dam and its

appurtenant works must include:

(a) the method and frequency of routine inspections and maintenance of the dam necessary to:

(i) remove and prevent the growth of trees or brush on the embankment of the dam and on the spillway system;

(ii) remove and prevent the accumulation of debris, obstructions, or other deleterious materials from upstream face of the dam and the spillway system;

(iii) ensure that all gates, orifices, dissipators, trash racks, and other appurtenances--including monitoring devices--that affect the proper operation of the dam and reservoir are kept in good repair and working order;

(iv) maintain adequate and suitable vegetation to prevent the erosion of the embankment and earth spillway for the dam; and

(v) determine that any seepage on the downstream slopes of the dam does not present a situation indicative of potential dam failure; and

(b) a plan for a detailed record of all maintenance required, including dates and results of inspections and complete information on all maintenance, rehabilitation, and improvements. This record must also include data, including photographic documentation, on the structural behavior of the dam embankment and spillway system for all major flood and seismic events.

(2) The plan must be developed in cooperation with those designated by the owner for carrying out the plan in an emergency, such as county disaster emergency coordinators, county sheriff, city police, engineer, and others. A written statement of agreement to participate in the plan must be signed by those responsible and be attached to the plan.

(3) The owner shall file the plan with the appropriate disaster and emergency services coordinator after approval by the department, and the owner shall provide certification of its filing to the department.

(4) The plan must include but not be limited to:

(a) a map of the evacuation area downstream of the dam based on the estimated inundation caused by a sudden breach of the dam during the design flood and non-flooding failure conditions. The evacuation area must be depicted on a USGS quadrangle map with the approximate travel time indicated at significant locations;

(b) an up-to-date notification directory with phone numbers of key county or municipal and emergency management officials, an engineer familiar with the dam's characteristics, downstream residents requiring immediate notification within the inundation area (listed in order by those affected first) , and the department;

(c) the current name of the owner or representative responsible for giving notification of a threat of failure;

(d) the general sites and availability of materials for emergency repairs such as filling erosion gullies and controlling seepage; and

(e) a list of CONTRACTORS and others that could provide assistance before, during, and after a dam failure or reference that the county resource book for disaster and emergency services has been examined and contains the necessary CONTRACTORS and others.

(5) The owner shall annually review and update the emergency procedures and warning plan.

(a) The owner of the dam or reservoir shall at all times follow the operation plan of the dam or reservoir, including the reservoir operation procedure, maintenance procedure for the dam and appurtenant works, and emergency procedures and warning plans as approved by the department;

(b) the initial filling of a completed new dam or repaired dam must be controlled by the owner and observed by the engineer at frequent intervals;

(c) a copy of the current and approved operation plan must be provided to the dam tender or operator;

(d) except in an emergency, no construction other than that necessary for the normal operation, maintenance, investigation, and monitoring of the dam and reservoir must be allowed on the dam or its appurtenant works unless a construction permit for such work has been approved by the department;

(e) an application for renewal of an operation permit must be submitted to the department before the operation permit lapses;

(f) the sale or conveyance of a permitted dam or the land on which the dam is located must not affect the validity of the permit. The owner in whose name the permit is granted must notify the department in writing of such change of ownership within the 30 days of such transfer; and

(g) permits must not be transferred from one dam to another.

(2) The department may cancel an operating permit whenever it determines that the dam or reservoir constitutes a danger to life. Whenever the department deems it is necessary to safeguard life, the department may amend the terms and conditions of any permit by issuing a new permit containing the revised terms and conditions. Such modifications are effective 90 days following issuance by the department of a revised permit, except when the department finds that a state of emergency exists, and that life would be endangered by delay. In case of an emergency declared by the department, the new conditions are effective immediately.

(3) Operating permits are renewed for a definite period of time, not to exceed 5 years, as determined by the department. In determining each period of approval, the department shall consider the circumstances pertinent to the situation, including the size and type of dam, hydraulic appurtenances, topography, geology, soil conditions, hydrology, climate, use of reservoir and the lands lying in the floodplains downstream from the dam, and results of the inspection reports.

(4) The department may issue or renew an operation permit if there is reasonable assurance that remedial measures identified in the periodic inspection report be completed within a period of time established in the operation permit or renewal.

(2) Design as well as preparation of the construction plans and specifications must be prepared by or under the direction of an engineer experienced in dam design and construction.

(3) An earthfill dam must be safe and stable during all phases of construction and operation of the reservoir. To accomplish this, the following criteria must be met:

(a) the embankment must be safe against overtopping during occurrence of the inflow design flood by the provision of sufficient spillway and outlet works capacity;

(b) the slopes of the embankment must be stable during construction and under all conditions of reservoir operation, including rapid drawdown of the reservoir;

(c) the embankment must be designed so as not to impose excessive stresses upon the foundation;

(d) seepage flow through the embankment, foundation, and abutments must be controlled so that no internal erosion or piping takes place and so there is no sloughing in the area where the seepage emerges;

(e) the embankment must be safe against overtopping by wave action;

(f) the upstream slope must be protected against erosion by wave action, and the crest and downstream slope must be protected against erosion due to wind and rain;

(g) the design must be such that the most severe earthquake that can be reasonably anticipated will not cause catastrophic failure and loss of life; and

(h) construction of the dam and its appurtenants must be constructed utilizing proper methods and control.

(4) Except as otherwise specified in ARM 36.14.501 to 36.14.504, concrete dams must be designed and constructed in accordance with principles at least equivalent to United States bureau of reclamation Design of Small Dams to its specified limits, or Design of Gravity Dams and Design of Arch Dams.

(5) Except as otherwise specified in ARM 36.14.501 to 36.14.504, earth dams retaining a flood water capacity of less than 12,500 acre-feet or a total capacity of less than 25,000 acre-feet measured to the primary emergency spillway must be designed and constructed in accordance with principles at least equivalent to United States soil conservation service TR-60, Earth Dams and Reservoirs. In this paragraph, total capacity means the total volume of space available for water and sediment upstream from a dam below the elevation at which discharge begins in the primary emergency spillway. In this paragraph, floodwater detention capacity is the capacity between the crest of the principal spillway and the elevation at which discharge begins in the primary emergency spillway sediment.

(6) Except as otherwise specified in ARM 36.14.501 to 36.14.504, earth dams greater than the limits specified in (5) must be designed and constructed at least equivalent to the United States bureau of reclamation Design of Small Dams to its limit of a 50-feet dam height, and to the corps standard beyond a 50-feet dam height.

(1) Spillway conveyance for high-hazard dams will be based on estimated loss of life downstream from the dam caused by spillway failure.

(2) The minimum inflow design flood for an estimated loss of life of 0.5 or less shall be the 500-year recurrence interval flood.

(3) The minimum inflow design flood recurrence interval for estimated loss of life greater than 0.5 and less than or equal to 5 shall be determined by multiplying the estimated loss of life by 1,000.

(4) The minimum inflow design flood for estimated loss of life greater than 5 and less than 1,000 shall be determined from the design precipitation derived using the following equations:

P_s = P_5,000 (10^rd) where

r = -0.304 + .435 log₁₀ (lol)

d = log₁₀ (PMP) - log₁₀ (P_5,000)

lol = estimated loss of life

PMP = probable maximum precipitation

P_5,000 = 5,000-year recurrence interval precipitation

P_s = design precipitation to meet spillway standard

(5) The minimum inflow design flood for estimated loss of life greater than or equal to 1,000 shall be the probable maximum flood.

(6) The reservoir and spillway must safely store and pass the runoff resulting from the minimum inflow design flood.

(7) As a minimum, the reservoir will be assumed at normal operation pool before the minimum inflow design flood begins.

(8) The spillway capacity may be smaller if an analysis shows that there is no additional loss of life expected from the dam failure flood than that observed for the minimum inflow design flood.

(2) Any dam that exceeds 50 feet in height must have a sufficient number of piezometers adequately monitoring the piezometric surface within the dam to identify unusual changes in seepage characteristics of the dam.

(3) All dams must have an adequate seepage monitoring and collection system.

(4) The department shall specify any other necessary instrumentation in the permit based upon the design being implemented and the information acquired during an investigation.

(2) The sides of the breach must be excavated to a slope that is stable and consistent with the natural angle of repose of adjacent material abutting the dam or as determined by the engineer.

(2) Periodic inspections must be made and a report completed on a frequency of at least once every 5 years or within the period stated in the terms of an operation permit for a high-hazard dam.

(3) The frequency of periodic inspections shall be set by the department after considerations including the condition of the dam, proximity to population centers, current design technology, and type of construction.

(4) The owner shall retain records of all inspections, including records of actions taken to correct conditions found in such inspections.

(5) Within 90 days of the periodic inspection, the owner shall deliver a copy of the report to the department, together with a statement of the owner's intent in regard to any deficient or unsafe items identified by the report, and a time schedule to remedy the items. The original copy of the report shall be retained by the owner.

(6) The owner shall bear the cost of the inspection.

(1) The inspection must include, but not be limited to:

(a) review and analysis of previous inspection reports and available data on the design, construction, operation, and maintenance of the dam and its appurtenances;

(b) visual inspection of the dam, its appurtenances, the downstream area, and all other areas affected by the structure;

(c) evaluation or plan for a full evaluation over no more than a 5-year period of the general conditions of the dam, spillways, and other appurtenances, including an assessment of the hydrologic and hydraulic capabilities, structural stability, and any other conditions that constitute or could constitute a hazard to the integrity of the structure;

(d) evaluation of operation, maintenance, emergency, and inspection procedures employed by the owner;

(e) analysis of piezometric levels or other data from any instrumentation or monitoring of the dam;

(f) review and analysis of the rate and volume of seepage and condition and maximum flow capability of any seepage collection system;

(g) review and documentation of the condition of surfaces and vegetation on the crest and slopes of the dam and area beyond the downstream toe of the dam;

(h) review of maximum operating water surface elevation and amount of freeboard;

(i) review and documentation of the condition of spillways and water level control structures, including all conduits exiting the dams; and

(j) other items the engineer determines are necessary to document and determine the safety of the dam.

(1) The engineer shall prepare a written report and photographic record of the inspection. The report must contain the following:

(a) the date and findings of the inspection and an assessment of the conditions of the dam and reservoir based on the visual observations, available data on the design, construction, operation, and maintenance of the structure, and hydrologic, hydraulic, stability, and other evaluations;

(b) recommendations for any critical or emergency measures or actions;

(c) recommendations for corrective measures or actions relating to design, construction, operation, maintenance, and inspection of the structure;

(d) recommendations for time periods appropriate for implementing any necessary emergency or corrective measures or actions to improve the safety of the dam to an acceptable level;

(e) recommendations for additional detailed studies, investigations, and analyses;

(f) recommendations for the safe storage level of the dam or reservoir; and

(g) recommendations for the time of the next inspection by an engineer.

(2) The engineer shall deliver the report and discuss it with the owner within 60 days of the investigation.

(a) failure of the dam; or

(b) the occurrence of a critical condition such that the integrity of the dam or any of its appurtenances is immediately threatened, including for example:

(i) excessive and unusual seepage on the outer slope or downstream from the toe of the dam or near or around a conduit through the dam as indicated by unusual damp areas, boils, cones, and deltas;

(ii) bulging of the downstream slope of the dam;

(iii) subsidence or cracking of the crest on either slope of the dam and slopes in the reservoir area;

(iv) substantial or threatening surface erosion, gullying, or wave erosion on the upstream or downstream slope of the dam, including berms and the area beyond the downstream toe of the dam and below or around conduits exiting the dam or spillways; and

(v) an inflow that equals or exceeds the maximum inflow design flood.

(a) immediately take remedial measures, notify the local sheriff, and notify the department of the emergency action or repairs or breaching to be instituted by the owner; and

(b) for dams being operated under an operation permit, the owner shall immediately implement the emergency action plan.

(a) the condition of a dam or reservoir or appurtenant work is so dangerous to the safety of human life or property as not to allow time for the issuance and enforcement of an order; or

(b) the owner fails to comply with an emergency order or emergency action plan or it cannot be ascertained if the owner has complied with the order or if the owner can't be found.

(2) The department may enter and conduct such investigations, tests, and analyses and take such corrective action as required to carry out the purposes of the act and this chapter.

(3) In applying emergency measures, the department shall direct the owner by order or, if conditions warrant it, the department may perform any of the following:

(a) lower the water level by releasing water from any impoundment or reservoir;

(b) completely empty the impoundment or reservoir;

(c) remove the dam; or

(d) take other steps as may be essential to safeguard human life or property.

(4) The department may continue to control such dam, impoundment, reservoir, and appurtenant works until they are rendered safe or the emergency occasioning the action has ceased.

(5) Orders must be sent to a dam owner by certified mail or served personally.

This rule has been repealed.

(a) name, address, and telephone number of the owner of the dam or reservoir;

(b) estimated capacity of the reservoir in acre-feet or dam crest height and surface area of the full pool;

(c) factual description of the complaint and any supporting information or data;

(d) location of the dam or reservoir;

(e) name, address, and telephone number of complainant; and

(f) notarized signature of the complainant.

(1) If an emergency condition does not exist, the department shall submit the affidavit of complaint to the owner for review and response within a reasonable time set by the department.

(2) If an emergency condition pursuant to ARM 36.14.701 exists, the department shall proceed pursuant to ARM 36.14.703 if the owner fails to immediately act.

(3) Upon review of the affidavit of complaint, owner's response, and all other pertinent department records, the department may conduct or order an inspection. If the department has insufficient data or information, the department shall conduct an inspection.

(4) Prior to the department-ordered inspection, notification must be given to the dam owner and complainant of the date and estimated cost of the inspection.

(a) Within a reasonable time, the owner shall provide all readily available engineering design and performance data to the department or inspector.

(b) The owner shall allow access and operate the dam and its facilities as directed by the inspector or the department for the inspection.

(5) If upon inspection the department finds the dam to be defective, the department shall order the necessary remedial action to eliminate the defect and make the dam, reservoir, or appurtenant works safe. The order must be in writing and delivered to the owner either personally or by certified mail.

(a) Remedial action may include submittal of an engineering design report, plans, and specifications.