Subchapter B. DAMS AND RESERVOIRS

§ 105.71. Scope.

 Except as provided in § §  105.3 and 105.12 (relating to scope; and waiver of permit requirements), this subchapter governs the construction, alteration, enlargement, repair, maintenance, operation and removal of a dam or reservoir regulated under the act.

   The provisions of this §  105.79 adopted August 11, 1978, effective August 28, 1978, 8 Pa.B. 2229; reserved September 26, 1980, effective September 27, 1980, 10 Pa.B. 3843. Immediately preceding text appears at serial page (47994).

PERMITS

§ 105.81. Permit applications for construction and modification of dams and reservoirs.

 (a)  In addition to the information required by §  105.13 (relating to permit applications—information and fees), permit applications under this subchapter for the construction or modification of dams and reservoirs shall give the following information:

   (1)  The name and address of the applicant.

   (2)  The location, type, size, height and purpose of the proposed dam and reservoir and appurtenant works.

   (3)  For projects involving storage of fluids or semifluids other than water, information concerning the chemical content, viscosity and other pertinent physical characteristics of the fluid or semifluid impounded.

   (4)  The storage capacity and reservoir surface areas for normal pool and maximum high water.

   (5)  Plans for purposed permanent monitoring of performance by instrument installations in the dam, including the purposes of the instrumentation. If no instrumentation is considered necessary, reasons for this judgment may be stated.

   (6)  As accurately as may be readily obtained, the area of the drainage basin, pertinent rainfall and streamflow records, and flood flow records and estimates.

   (7)  The proposed time for commencement and anticipated completion of construction.

   (8)  The method and schedule of operation of the dam including an emergency warning system and operation plan if required under §  105.134 (relating to emergency action plan).

   (9)  Plans for control of erosion and water pollution during the anticipated construction operations including plans for adequate measures to limit the erosion of the soil from exposed slopes after completion of construction. The plans shall indicate that adequate control measures will be taken during construction to protect the quality of stream flow below the project site. The application shall include a copy of a letter from the conservation district in the county where the project is located indicating that the district reviewed the erosion and sediment control plan of the applicant and considers it to be satisfactory.

   (10)  Proof of title or adequate flowage easements for land area below the top of the dam elevation that is subject to inundation.

   (11)  Other information the Department may require.

 (b)  The application shall be accompanied by a design report, construction plans and specifications, in sufficient detail to evaluate the safety, adequacy and suitability of the proposed work.

 (c)  The applicant shall conduct and submit the results of the investigations and tests as the Department, in its judgment, believes are necessary to determine the safety, adequacy and suitability of design, including but not limited to:

   (1)  Data concerning subsoil and rock foundation conditions and the materials entering into the construction of the dam or reservoir.

   (2)  Data concerning exploratory pits, drilling, coring and tests to determine seepage rates.

   (3)  Data concerning the strength tests necessary to measure the physical properties and behavior of foundation and embankment materials at the dam or reservoir site.

   (4)  Data concerning the geology of the dam or reservoir area, indicating possible hazards such as faults, weak seams and joints.

   (5)  Data concerning availability and quality of construction materials.

   (6)  Other information as may be necessary, including the design calculations for the dam, which shall be made available to the Department on request.

 (d)  Plans and specifications and the results of tests or investigations shall be prepared under the supervision of and certified by a registered professional engineer experienced in dam design and construction and assisted by qualified engineers, geologists and other specialists, when necessary.

 (a)  In addition to information required by § §  105.13 and 105.14 (relating to permit applications—information and fees; and review of applications), a permit application for the operation and maintenance of existing dams and reservoirs shall give the following information:

   (1)  The name and address of the applicant.

   (2)  The location, type, size, height and purpose of the existing dam and reservoir and appurtenant works.

   (3)  For projects involving storage of fluids or semifluids other than water, information concerning the chemical and physical characteristics of the fluid or semifluid impounded.

   (4)  The storage capacity and reservoir surface areas for normal pool and maximum high water.

   (5)  A description of facilities and plans for monitoring the performance of the dam.

   (6)  Information on the area of the drainage basin, rainfall and stream flow records, and flood flow records and estimates, when available.

   (7)  Information readily available regarding the foundation, specifications and construction of the dam.

   (8)  The method and schedule of operation of the dam, if deemed necessary by the Department.

   (9)  The emergency warning plan for the dam or reservoir, if completed, or work plan to prepare and submit an emergency warning plan in accordance with § §  105.131 and 105.134 (relating to operation and monitoring plans; and emergency action plan).

   (10)  Proof of title or flowage easements for land areas below the top of the dam elevation that is subject to inundation.

   (11)  Reports of the most recent inspections of the dam conducted by the owner or by the State or Federal government agencies.

   (12)  Other information as the Department may require.

 (b)  The Department may waive or modify one or more of the application content requirements set forth in subsection (a) if the information required is not available and is not essential to determining the safety of the dam or reservoir or compliance by the dam or reservoir with the requirements of this chapter.

   The provisions of this §  105.87 adopted August 11, 1978, effective August 28, 1978, 8 Pa.B. 2229; reserved September 26, 1980, effective September 27, 1980, 10 Pa.B. 3843. Immediately preceding text appears at serial page (38865).

CLASSIFICATION AND DESIGN CRITERIA

§ 105.91. Classification of dams and reservoirs.

 (a)  A dam or reservoir shall be classified in accordance with size and the hazard potential which might occur in the event of an operational or structural failure. In approving a hazard potential classification, the Department will consider, without limitation:

   (1)  The height of the dam and storage capacity of the reservoir.

   (2)  The physical characteristics and extent of actual and projected development of the dam site and downstream areas.

   (3)  The relationship of the site to existing or projected industrial, commercial and residential areas and other land uses downstream which may be affected by a dam failure.

 (b)  The following shall be the classifications and descriptions as used in this subchapter:

SIZE CLASSIFICATION*

Class	Impoundment Storage (Acre Feet)	Dam Height (Feet)
A	Equal to or greater than 50,000	Equal to or greater than 100
B	Less than 50,000 but greater than 1000	Less than 100 but greater than 40
C	Equal to or less than 1000	Equal to or less than 40

   *Note: Size classification may be determined by either storage or height of structure, whichever gives the higher category.

HAZARD POTENTIAL CLASSIFICATION
Extent of Development

Category	Loss of Life	Economic Loss
1	Substantial	Excessive (extensive residential, commercial, agricultural and substantial public inconvenience)
2	Few (no rural communities or urban developments and no more than a small number of habitable structures)	Appreciable (damage to private or public property and short duration public inconvenience)
3	None expected (no permanent structure for human habitation)	Minimal (undeveloped or occasional structures with no significant effect on public inconvenience)

   The provisions of this §  105.91 amended under the Dam Safety and Encroachments Act (32 P. S. § §  693.1–693.27); The Clean Streams Law (35 P. S. § §  691.1—691.1001); section 7 of the act of June 14, 1923 (P. L. 704, No. 294) (32 P. S. §  597); sections 514, 1901-A, 1908-A, 1917-A and 1920-A of The Administrative Code of 1929 (71 P. S. § §  194, 510-1, 510-8, 510-17 and 510-20); and the Flood Plain Management Act (32 P. S. § §  679.101—679.601).

   The provisions of this §  105.91 adopted September 10, 1971, effective September 11, 1971, 1 Pa.B. 1804; amended August 11, 1978, effective August 28, 1978, 8 Pa.B. 2229; amended September 26, 1980, effective September 27, 1980, 10 Pa.B. 3843; amended October 11, 1991, effective October 12, 1991, 21 Pa.B. 4911. Immediately preceding text appears at serial pages (117680) and (149139).

 (a)  The foundation of a dam or reservoir shall be stable under all probable conditions.

 (b)  In analyzing the stability of the foundation of a proposed or existing dam or reservoir, the applicant shall consider all of the following factors:

   (1)  The seismic forces at the site.

   (2)  The shearing strength of the foundation.

   (3)  Settlement and subsidence.

   (4)  Leakage, permeability and solubility.

 In the construction of dams and reservoirs, allowable stresses shall conform to the current standards accepted by the engineering profession.

 (a)  Every dam shall be provided with a spillway system which is capable of safely conveying the design flood of the dam without endangering the safety or integrity of the dam.

 (b)  Each spillway shall include a satisfactory means of dissipating the energy flow at its outlet to assure conveyance of flow without endangering the safety and integrity of the dam or the natural environment of the stream.

 Sufficient freeboard may be required to prevent overtopping of the dam and to allow for wave and ice action.

   The provisions of this §  105.95 amended under the Dam Safety and Encroachments Act (32 P. S. § §  693.1–693.27); The Clean Streams Law (35 P. S. § §  691.1—691.1001); section 7 of the act of June 14, 1923 (P. L. 704, No. 294) (32 P. S. §  597); sections 514, 1901-A, 1908-A, 1917-A and 1920-A of The Administrative Code of 1929 (71 P. S. § §  194, 510-1, 510-8, 510-17 and 510-20); and the Flood Plain Management Act (32 P. S. § §  679.101—679.601).

 (a)  Dams shall include a device to permit the draining of the reservoir within a reasonable period of time as determined by the Department unless the Department determines that an outlet works is not feasible for a specific dam.

 (b)  In determining the reasonable time period for drainage of the reservoir, the Department may consider, without limitation, the following factors:

   (1)  The damage potential posed by possible failure of the dam.

   (2)  The risk and nature of potential failure and the time likely to be available to avert the failure after notice of conditions threatening the safety or stability of the dam.

   (3)  The purpose of the dam and reservoir.

   (4)  The capacity and stability of available drainage courses to convey the waters released from the reservoir in the event of emergency drainage.

   (5)  The influence of rapid drawdown on the stability of the dam, its appurtenant works and the upstream natural slopes of the reservoir.

 (c)  Each outlet works shall include a means of dissipating the energy of flow at its outlet to assure conveyance of flow without endangering the safety and integrity of the dam or the natural environment of the stream.

 (a)  Dams shall be structurally sound and shall be constructed of sound and durable materials. The completed structure shall be stable under all probable conditions of operation.

 (b)  In reviewing the stability of a structure, the Department may consider, without limitation, the following:

   (1)  The physical properties of the materials available for construction.

   (2)  The seismic and hydraulic forces affecting the structure.

   (3)  The methods of construction.

   (4)  The conditions of operation of the dam and reservoir.

 (a)  The discharge capacity or storage capacity, or both, shall be capable of safely accommodating the recommended design flood for the size and hazard potential classification of the dam as determined by §  105.91 (relating to classification of dams and reservoirs). The design flood is intended to represent the largest flood that need be considered in the evaluation of a given project. When a range of design flood is indicated, the magnitude that most closely relates to the size and hazard potential shall be selected. Design flood criteria shall be as indicated in the following table:

 (b)  The Department may, in its discretion, require consideration of a minimum design flood for a class of dams or reservoirs in excess of that set forth in subsection (a) when it can be demonstrated that the design flood requirement is necessary and appropriate to provide for the integrity of the dam or reservoir and to protect life and property with an adequate margin of safety.

 (c)  The Department may, in its discretion, consider a reduced design flood for a class of dams or reservoirs when it can be demonstrated that the design flood provides for the integrity of the dam or reservoir and protects life and property with an adequate margin of safety.

 Whenever a dam or reservoir is proposed to be constructed in or as a part of an existing or proposed subdivision development, the Department will include in the permit the conditions as are necessary to prevent construction of structures on lands which may be subject to flooding caused by the maximum pool of the dam and to require the permittee to adequately inform potential buyers or lessees of the restrictions.

   The provisions of this §  105.99 adopted September 26, 1980, effective September 27, 1980, 10 Pa.B. 3843.

CONSTRUCTION REQUIREMENTS AND PROCEDURES

§ 105.101. Notices and reports.

 At least 15 days prior to commencement of construction, the permittee shall notify the Department, in writing, of the proposed time for commencement of work. Thereafter, a detailed report on the status of construction shall be submitted monthly to the Department of Environmental Resources; Division of Dam Safety; Post Office Box 2357, Harrisburg, Pennsylvania 17120, until construction work has been completed.

   The provisions of this §  105.101 adopted September 10, 1971, effective September 11, 1971, 1 Pa.B. 1804; amended August 11, 1978, effective August 28, 1978, 8 Pa.B. 2229; amended September 26, 1980, effective September 27, 1980, 10 Pa.B. 3843. Immediately preceding text appears at serial page (47996).

 (a)  Work shall be conducted under the oversight and supervision of a competent engineer approved by the Department, and the engineer or a competent representative shall be on the work site during significant construction activities until the completion of the dam.

 (b)  The permittee shall file with the Department at least 15 days prior to the commencement of construction a statement setting forth the name of the contractors conducting the work authorized by the permit and the names and employers of personnel responsible for the supervision of construction.

   The provisions of this §  105.102 adopted September 10, 1971, effective September 11, 1971, 1 Pa.B. 1804; amended August 11, 1978, effective August 28, 1978, 8 Pa.B. 2229; amended September 26, 1980, effective September 27, 1980, 10 Pa.B. 3843. Immediately preceding text appears at serial page (47997).

 (a)  No earth or other embankment material which is in a frozen condition may be covered or placed in embankments.

 (b)  Masonry and concrete may not be placed in freezing weather except under conditions approved by the Department.

 (a)  Work shall be conducted in such a manner as to minimize the destruction of or damage to trees and other vegetation on and adjacent to the construction site.

 (b)  Vegetation cleared and removed from the site shall be disposed of in accordance with all applicable laws and regulations.

 Activities and facilities on the construction site shall be conducted and operated in such manner as to avoid pollution of the air and waters of this Commonwealth and in accordance with applicable laws and the provisions of this title.

 (a)  Within 30 days after the completion of work authorized by permit issued under this subchapter, the permittee shall file with the Department a certified statement signed by the supervising engineer and by the permittee that work has been performed in accordance with the terms and conditions of the permit; with the approved maps, plans, profiles and specifications; and with applicable laws and the provisions of this title.

 (b)  Within 90 days after the completion of work, the permittee shall file with the Department a set of final ‘‘as built’’ plans for the project, showing changes from the original plans and specifications.

   The provisions of this §  105.107 adopted September 26, 1980, effective September 27, 1980, 10 Pa.B. 3843.

   This section cited in 25 Pa. Code §  105.445 (relating to waiver of certain requirements).

WATER STORAGE AND DISCHARGE

§ 105.111. Commencement of water storage.

 The permittee shall notify the Department, in writing, at least 1 week in advance of the date proposed for the commencement of water storage in the reservoir or pond created by the dam for which the permit is issued. The Department may, at its discretion, require that a representative of the Department be at the site before or during the filling of the pond or reservoir.

   The provisions of this §  105.111 adopted September 10, 1971, effective September 11, 1971, 1 Pa.B. 1804; amended August 11, 1978, effective August 28, 1978, 8 Pa.B. 2229; amended September 26, 1980, effective September 27, 1980, 10 Pa.B. 3843. Immediately preceding text appears at serial pages (47997) to (47998).

 During the period of construction, alteration, enlargement or repair and during the period that the pond or reservoir is being filled, the permittee shall allow a sufficient flow of water, as determined by the Department, into the stream below the dam to support fish and other aquatic life and to preserve the water quality in the stream.

 (a)  The Department will impose general and special conditions regarding release rates in a permit for a dam or reservoir that it deems necessary to maintain stream flows for the purposes of protection of public health, water quality control, conservation of fisheries and aquatic habitat, improvement of recreation and protection of instream and downstream water uses. The appropriate release rates for the dams and reservoirs shall be established in accordance with subsections (b) and (c).

 (b)  For dams or reservoirs constructed after August 28, 1978:

   (1)  The minimum release rate unless modified in accordance with paragraph (2) shall be the average consecutive 7 day flow having a recurrence interval of once in 10 years (Q 7-10) plus an additional release rate determined by the following formula:

   (2)  The Department may modify the minimum release rate, or provide variable schedules or releases considering the following factors:

     (i)   The purposes stated in subsection (a).

     (ii)   Particular stream requirements, including the particular needs of instream and downstream water uses and riparian rights.

     (iii)   The particular uses and purposes of the dam or reservoir.

     (iv)   The particular engineering, hydrologic and economic factors affecting the ability of the dam or reservoir to provide the releases.

 (c)  For dams and reservoirs constructed prior to August 28, 1978, the Department will determine a reasonable schedule for release rates, considering all of the following:

   (1)  The purposes stated in subsection (a) and the particular needs of instream and downstream water uses on the affected stream.

   (2)  The capacity of existing release works at the dam and feasibility of potential modification of the release works.

   (3)  The yield of the reservoir, and its capability to meet release requirements and satisfy the purposes and uses of the reservoir.

 (d)  Every dam shall at all times be operated in such manner as to allow the required flow of water into the stream below the dam as established under this section, and as otherwise necessary to support fish and other aquatic life and to assure compliance with the water quality criteria set forth in Chapter 93 (relating to water quality standards) and to provide for other instream uses for the affected stream.

   The provisions of this §  105.114 adopted August 11, 1978, effective August 28, 1978, 8 Pa.B. 2229; reserved September 26, 1980, effective September 27, 1980, 10 Pa.B. 3843. Immediately preceding text appears at serial pages (38870) to (38871).

PROTECTION AND RESTORATION OF AQUATIC LIFE

§ 105.121. Fishways.

 Upon the request of the Fish Commission, the permittee shall install and maintain chutes, slopes, fishways, gates or other devices that the Fish Commission may require under sections 185—187 of The Fish Law of 1959 (30 P. S. § §  185—187) (Repealed).

 Impounded waters which are inhabited by fish may not be drawn down except with the written approval of the Fish Commission issued under section 191 of The Fish Law of 1959 (30 P. S. §  191) (Repealed).

   The provisions of this §  105.122 adopted September 10, 1971, effective September 11, 1971, 1 Pa.B. 1804; amended August 11, 1978, effective August 28, 1978, 8 Pa.B. 2229; amended September 26, 1980, effective September 27, 1980, 10 Pa.B. 3843. Immediately preceding text appears at serial page (38872).

 If the Department finds that construction of a dam or reservoir has so substantially disrupted aquatic life as to preclude natural restoration of the stream ecology within a reasonable period of time, the permittee shall be required to submit and implement a plan to restore the aquatic life of the stream to its prior condition, to the maximum extent possible. The plan shall be subject to review and modification by the Department in consultation with the Fish Commission and shall include but not be limited to:

   (1)  Placement of bed gravel.

   (2)  Stabilization of banks and bed.

   (3)  Installation of stream improvement devices.

   (4)  Revegetation of stream and banks.

   (5)  Stocking of fish and other aquatic life.

   The provisions of this §  105.125 adopted September 10, 1971, effective September 11, 1971, 1 Pa.B. 1804; reserved August 11, 1978, effective August 28, 1978, 8 Pa.B. 2229. Immediately preceding text appears at serial page (4594).

OPERATION, MAINTENANCE AND EMERGENCIES

§ 105.131. Operation and monitoring plans.

 (a)  In addition to the requirements of § §  105.51—105.54 (relating to operation, maintenance and inspection), the permittee or owner of a dam or reservoir shall follow the method and schedule of operation of the dam or reservoir, including the emergency action plan if required by §  105.134 (relating to emergency action plan), as approved by the Department and shall implement a plan approved by the Department for permanent monitoring of performance by instrument installation in the dam.

 (b)  A permittee or owner of a dam or reservoir may not modify or cease implementation of all or part of the approved plans and methods of operation or monitoring without the prior approval of the Department.

 (c)  The permittee or owner of a dam or reservoir shall operate and maintain the dam in accordance with the authorized plans and specifications. Normal repairs and maintenance of the dam and the reservoir’s design storage capacity will not require further authorization except as provided in §  105.122 (relating to drawdown of impounded waters).

   The provisions of this §  105.131 amended under the Dam Safety and Encroachments Act (32 P. S. § §  693.1–693.27); The Clean Streams Law (35 P. S. § §  691.1—691.1001); section 7 of the act of June 14, 1923 (P. L. 704, No. 294) (32 P. S. §  597); sections 514, 1901-A, 1908-A, 1917-A and 1920-A of The Administrative Code of 1929 (71 P. S. § §  194, 510-1, 510-8, 510-17 and 510-20); and the Flood Plain Management Act (32 P. S. § §  679.101—679.601).

   The provisions of this §  105.131 adopted September 10, 1971, effective September 11, 1971, 1 Pa.B. 1804; amended August 11, 1978, effective August 28, 1978, 8 Pa.B. 2229; amended September 26, 1980, effective September 27, 1980, 10 Pa.B. 3843; amended October 11, 1991, effective October 12, 1991, 21 Pa.B. 4911. Immediately preceding text appears at serial page (117690).

 The permittee or owner of a dam or reservoir shall follow the inspection schedule set forth in §  105.53 (relating to inspections by owners and inspection reports).

 The permittee shall immediately take steps that the Department may prescribe as necessary to preserve the structural stability and integrity of the dam and protect health, safety and property.

 (a)  The owner of a dam or reservoir that may cause loss of life or serious damage to property if a failure of the dam occurs, shall develop an emergency action plan to be followed in the event of a dam hazard emergency. The emergency action plan shall be submitted to and approved by the Department and local emergency management officials prior to commencement of water storage in the reservoir or pond created by the dam during any stage of construction of the dam. The emergency action plan shall, at a minimum, contain the following elements:

   (1)  An identification of the area below the dam which may be threatened with loss of life or serious damage to property if a failure of the dam occurs.

   (2)  A listing of key municipal and emergency management officials and their telephone numbers. The list shall be readily available at the dam site near a telephone or other means of communication, if available.

   (3)  An identification of handicapped or other persons who may have difficulty evacuating the area which may be threatened if a failure of the dam occurs. Procedures for identifying and evacuating these people in a dam hazard emergency shall be developed in cooperation with local and emergency management officials.

 (b)  For an existing dam or reservoir that may cause loss of life or serious damage to property if failure of the dam occurs, an emergency action plan shall be submitted to and approved by the Department and local emergency management officials.

 (c)  In addition to the requirements in subsections (a) and (b), the owner of a high hazard dam shall post notices in public places in areas that may be affected by the failure of the dam; for example, areas where public water or sewage service may be interrupted. The notice shall indicate that copies of the emergency action plan are available for review at the appropriate county and municipal emergency management offices. Also, the notice shall be posted by the owner in the following public places within each political subdivision situated within the inundation area downstream of the dam:

   (1)  The city, borough or township building.

   (2)  The police department offices.

   (3)  The fire company halls.

   (4)  The tax collector’s office.

   The provisions of this §  105.134 amended under the Dam Safety and Encroachments Act (32 P. S. § §  693.1–693.27); The Clean Streams Law (35 P. S. § §  691.1—691.1001); section 7 of the act of June 14, 1923 (P. L. 704, No. 294) (32 P. S. §  597); sections 514, 1901-A, 1908-A, 1917-A and 1920-A of The Administrative Code of 1929 (71 P. S. § §  194, 510-1, 510-8, 510-17 and 510-20); and the Flood Plain Management Act (32 P. S. § §  679.101—679.601).

   The provisions of this §  105.134 adopted September 26, 1980, effective September 27, 1980, 10 Pa.B. 3843; amended October 11, 1991, effective October 12, 1991, 21 Pa.B. 4911. Immediately preceding text appears at serial pages (117691) to (117692).

 (a)  For the purposes of this section, a dam hazard emergency means a condition which the Department, permittee or owner of the dam reasonably finds constitutes an imminent threat to life or property above or below a dam, whether arising from the condition of the dam and appurtenant works or extraordinary natural conditions, affecting the safety and stability of the dam, including, but not limited to, flood, earthquake, fire and ice jam.

 (b)  The emergency procedures and the emergency warning system and operation plan required by § §  105.63 and 105.134 (relating to emergency procedures; and emergency action plan) shall be followed by the permittee and owner of a dam or reservoir in the event of an actual or potential dam hazard emergency.

 (c)  If a dam hazard emergency exists, the Department and the permittee or owner of the dam shall immediately notify appropriate emergency management officials of the existence of the hazard and request the authorities to initiate appropriate action to assure protection of life and property; and the permittee or owner shall immediately take the steps as are necessary to prevent dam failure or loss of life or property, including, but not limited to, the following:

   (1)  Draw down of the reservoir.

   (2)  Reinforcement of the dam structure.

   (3)  Breach or removal of the dam.

   (4)  Removal of debris.

   (5)  Repair or installation of structures necessary to assure the stability and safety of the dam.

 (d)  The Department, upon determining that a dam hazard emergency exists, will notify the owner immediately to take steps the Department determines are necessary to prevent dam failure or loss of life or property.

   The provisions of this §  105.135 adopted September 26, 1980, effective September 27, 1980, 10 Pa.B. 3843.

 (a)  For purposes of this section, an unsafe dam means a dam which meets one or more of the following criteria:

   (1)  A dam with deficiencies of such a nature that if not corrected could result in the failure of the dam with subsequent loss of lives or substantial property damage. This determination is based on good engineering judgment or the application of the guidelines established for the National Dam Inspection Program.

   (2)  A dam classified as unsafe under the National Dam Inspection Program.

   (3)  A dam declared as unsafe by the Department.

 (b)  The owner of an unsafe dam shall do the following:

   (1)  Immediately notify the Department upon receipt of any information indicating the dam is unsafe.

   (2)  Drain the dam as approved or required by the Department.

   (3)  Within time limits established by the Department, submit a plan for removal of the dam, a plan for repair of the dam or an application for a permit authorizing modification of the dam under subsection (c).

   (4)  Following approval of the plan or permit by the Department, undertake and complete actions to remove or repair the dam or implement the modifications to the dam within the time limits set by the Department.

 (c)  The Department may issue a permit for modification of an unsafe dam, under section 9 of the act (32 P. S. §  693.9), which authorizes the owner of an unsafe dam to modify the dam within the time prescribed in the permit to meet the requirements of the act and this chapter. The permit shall be conditioned upon:

   (1)  Compliance by the owner of the dam with a prescribed schedule for correction or modification of the unsafe condition within the shortest time period technically feasible and economically achievable.

   (2)  Implementation by the owner of the dam of measures deemed necessary by the Department to reduce risks to health and safety pending correction or modification of the unsafe condition, including but not limited to special provisions relating to operation, emergency planning, monitoring and warning systems, and development of an alternative source of water supply if the dam serves as a water supply dam.

 (d)  In determining whether to require removal of an unsafe dam or to permit the owner to modify the dam, the Department will consider whether there is a substantial adverse impact to the public health and safety which will result from the draining and removal of the dam, and whether that adverse impact outweighs the danger to public health and safety, which outweighing will result in allowing the unsafe dam to remain until it has been modified.

 (e)  At the discretion of the Department, a public hearing may be held in the affected area prior to the issuance of a permit authorizing modification of an unsafe dam over a period of more than 6 months, to inform affected communities of the risks which may result from allowing the unsafe dam to remain standing or to impound water during the time necessary to complete the modifications.

 (f)  If the Department finds that conditions upon which the permit authorizing modification was issued have substantially changed or that the owner does not meet the schedule for modification contained in the permit, the Department will review the status of the dam. An extension of the time period for completion of a modification may be issued by the Department if the owner has proceeded in good faith with the previous schedule of modification and the requirements of subsections (c) and (d) are met.

 (g)  Nothing in this section may be construed to limit the power of the Department to take immediate action, prior to public hearing, to do one or more of the following:

   (1)  Revoke or suspend a permit where deemed necessary by the Department to protect public health and safety.

   (2)  Order correction or abatement of a dam hazard emergency under §  105.135 (relating to dam hazard emergencies)

   (3)  Take another action authorized by law.

   The provisions of this §  105.136 adopted September 26, 1980, effective September 27, 1980, 10 Pa.B. 3843.