Sec. 26.17.04.05. Dams and Reservoirs

A. In addition to the general requirements in Regulation .04 of this chapter, the following special requirements shall apply to applications for dams and reservoirs:

(1) A person who applies to construct, reconstruct, repair, or alter a dam or reservoir shall engage a registered professional engineer, practicing in accordance with the laws of Maryland and qualified in the field of dam design and construction to prepare the designs and specifications and to provide supervision during construction of the proposed works. The engineer shall be the engineer-in-charge and shall:

(a) Be responsible for assuring that the designs conform to the high standards of professional competence in the specialty of dam design and construction;

(b) Assure that the construction is carried out in strict accordance with the approved plans and specifications and under the provisions of the permit; and

(c) Submit to the Administration a resume of all previous dam design and construction experience, listing specific responsibilities and a written certification of qualification to act as the engineer-in-charge.

(2) If an engineering team is planned for the design and construction, one registered professional engineer shall act as the engineer-in-charge. However, each individual on the project team shall document that individual's area of responsibility and technical experience. This documentation shall accompany the permit application.

(3) Making Application. The procedure for obtaining a permit for construction, reconstruction, repair, or alteration of a dam or reservoir is established in two steps:

(a) Step One. Plan Development Phase of Permit for a Waterway Obstruction. The applicant shall first obtain the Administration's written approval of the classification of the dam as outlined in §B of this regulation. The applicant shall then submit to the Administration an application which includes a feasibility report. Upon approval of the completed application, the Administration shall issue a Plan Development Permit. The decision of the Administration to issue or deny a Plan Development Permit shall constitute a final decision for the purposes of appeal to the Board of Review pursuant to Natural Resources Article, §1-107, Annotated Code of Maryland. The feasibility report shall include the following:

(i) Objectives and purposes of the project.

(ii) Alternate proposals studied.

(iii) General description of proposed dam and reservoir, including a plan view and cross section.

(iv) Conclusions on the dam site and adjacent valley walls and floor based upon geologic maps, surface investigations, seismic, geophysical, or geotechnical studies, or any preliminary soil borings made.

(v) Conclusions on the safety and effectiveness of the dam in impounding water.

(vi) Hydrologic studies including the determination of the inflow design flood, the danger reach, and the proposed operation of the dam and reservoir.

(vii) A map showing the project location, ownership of land affected, and showing any existing or proposed water or sewer lines, pipelines or electric transmission lines crossing the impoundment area and their planned relocation or protection. The map shall also show the location of other existing or proposed dams, reservoirs or other water resource projects, whose conditions of flow or operations may affect or be affected by this proposed project.

(viii) Type and source of materials to be used in construction. When natural materials (earth, rock, etc.) are to be used, the engineer shall indicate the approximate structural properties and availability of each kind of material.

(ix) Photographs of the proposed site.

(x) Estimated benefits from the project, including the design life of the project.

(xi) Estimated cost of the project and length of time required for construction of the structure and filling of the reservoir.

(xii) The owner's written assurance that funds will be available to complete the project as planned and for continued maintenance of the project throughout the life of the structure.

(xiii) An environmental study that includes measures to preserve or enhance the aesthetic, scenic, and wild values at the project site and upstream and downstream of the project. If the project is on a stream within the State Scenic and Wild Rivers Program, this information shall include measures to be taken to preserve the aesthetic and scenic values and the wild qualities of the stream.

(xiv) Foundation investigations shall define the location, type, strength, and other pertinent characteristics of the foundation material. Foundation investigations shall further disclose ground water conditions and other applicable information necessary for analysis of possible seepage problems.

(xv) Topographic surveys shall be made in sufficient accuracy to define the volume of storage in the reservoir and the flow limits. Property lines shall be shown in order that any potential effects of the water in the reservoir on adjacent properties may be determined. The downstream area shall be investigated and, if necessary, surveyed in order to establish the area of potential damage in case of failure.

(xvi) Establishment of proposed minimum releases after the reservoir is filled.

(b) Step Two. Construction Phase of Permit for a Waterway Obstruction. Before the Administration may issue a construction permit for the dam or reservoir, a separate permit application shall be accompanied by final construction plans, specifications, and other information that may be required. Final construction plans, specifications, and other data required before a permit may be issued shall include the following:

(i) Design report with all pertinent computations, including: geology (location and logs of soil and rock borings, conclusions, etc.); soil or rock mechanics tests; hydrology; design criteria; hydraulic design (flood routing, stage storage curve referenced to the lowest drain, velocities in downstream channel, etc.); structural design; stability analysis (including rapid drawdown); and, quantities and cost estimates.

(ii) Construction plans and location sketch, showing borrow areas, spoil areas, etc.

(iii) Construction specifications.

(iv) Provisions for minimum releases during construction and reservoir filling.

(v) Time schedule for construction.

(vi) Approved grading and sediment control plan, showing the measures for controlling sediment loss during and after construction.

(vii) Maintenance plan describing the steps to be followed by the owner to provide for the continued maintenance of the dam and reservoir during the expected life of the structure. This plan shall describe what work is to be called for at periodic intervals or when necessary to keep the structure in good condition. Among other items it shall address mowing or cutting of brushy growth on embankments, preventing erosion or gullying of embankment surfaces, clearing of toe drains, the prevention of accumulation of trash and debris, the protection against rust and spalling, and the exercise of valves or other mechanical equipment. The description of this program shall be submitted to this Administration for approval and inclusion among the required conditions of the construction permit.

(viii) Operations plan describing the steps to be followed by the owner to provide for the safe operation of the dam and reservoir and the continued minimum releases, withdrawals, etc.

(ix) A warning plan for Category I and Category II dams describing the steps to be followed in notifying persons whose lives, property, or health may be endangered by failure, improper operation, or other circumstances affecting the safety of the dam. The warning plan shall identify the most practical and expeditious means for notifying potentially affected persons in close proximity to the dam or property owners.

(x) A requirement by the Administration that the applicant post a construction bond, irrevocable letter of credit, or other security acceptable to the Administration to assure that funds are available to complete the construction of the proposed project and for continued maintenance of the project throughout the life of the structure.

B. Structure Classification and Design Criteria.

(1) Classification of Dams. The following table sets forth judgmental factors for minimizing the risk associated with the design of dams. The table is intended only as a guide. A proposed dam shall satisfy all four factors (normal pool storage volume, normal depth, potential for loss of life, and potential for damage) in order to avoid classification in a more rigorous category. Failure damage potential shall consider future development and use of the area flooded throughout the danger reach and the damage which would be expected from a complete breaching of the dam. If, in the opinion of the Administration, future development is probable in the area flooded throughout the danger reach, the dam shall be classed in Category I. The classification of the proposed dam shall be assigned by the Administration after the applicant has provided information on the potential damage within the danger reach, as defined herein. After the classification has been assigned, the inflow design flood and spillway design may be established. Dams qualifying for the Category III classification may be classed in Category IV, if all of the requirements of Environment Article, §5-503(b), Annotated Code of Maryland, are met with the exception of §5-503(b)(1).

GUIDE TO CLASSIFICATION OF DAMS

Category	Normal Pool Storage Volume in acre-feet)	Normal Depth (in feet)	Potential for Loss of Life	Potential for Damage
I	20,000 or more	50 or more	probable	Serious damage to: residential, industrial, or commercial buildings; important public utilities, public roads; or railroads
II	1,000 or more and less than 20,000	25 or more and less than 50	small possibility	Located in predominately rural or agricultural areas where failure may cause damage to isolated residences or cause interruption of use or service of public utilities or roads. Damage is within the financial capability of owner to repair.
III	less than 1,000	less than 25	very unlikely	Damage is of same magnitude as cost of dam and within the financial capability of owner to repair.
IV*	less than 100	less than 15

*Category IV is reserved for those structures which have a contributing drainage area of less than 1 square mile (640 acres), and a normal depth of water less than 15 feet above the original stream bed, and a normal surface area less than 12 acres.

(2) Danger Reach. A danger reach shall be established for all proposed dams by routing a flood hydrograph resulting from a failure of the structure. Computation of the danger reach is an iterative process and, based upon the potential for damage and loss of life, may necessitate reclassification to a higher category by the Administration. The danger reach shall be established using methods that compare the depth and aerial extent of the flood waters without and with the proposed dam as follows:

(a) The inflow design flood shall be flood routed throughout the downstream valley without the proposed dam in place.

(b) A dam-breach flood wave shall be routed throughout the downstream valley assuming failure of the dam. The following procedures are incorporated by reference and shall be considered acceptable by the Administration:

(i) DAMBRK-The NWS Dam-Break Flood Forecasting Model, The Hydrologic Engineering Center, U.S. Army Corps of Engineers, February, 1984;

(ii) HEC-1 Flood Hydrograph Package, Computer Program 723-X6-L2010, The Hydrologic Engineering Center, U.S. Army Corps of Engineers, September, 1981 (Revised January, 1985);

(iii) Technical Release Number 66, Simplified Dam-Breach Routing Procedure (Revised December, 1981).

(c) Under §B(2)(b) of this regulation, consideration shall also be given to the peak discharge caused by the design storms in the uncontrolled area below the dam, together with the flow over and through the dam.

(3) Inflow Design Flood. The inflow design flood for Category I dams shall be the probable maximum flood. For Category II dams the inflow design flood shall be the standard project flood or the largest flood of record, whichever is greater. For Category III dams the inflow design flood shall be one having a recurrence interval of once in 100 years or longer. For Category IV dams the inflow design flood shall be as defined in USDA, Natural Resource Conservation Service, Maryland Conservation Practice, Standard Pond Code 378 (January, 2000), which is incorporated by reference in COMAR 26.17.02.01-1B(2). Criteria shall be provided or approved by the Administration for each of the above inflow design floods.

(4) Spillway Design. Established procedures for spillway design and capacity, when properly applied, will be accepted by the Administration. The effects of storage may be taken into account in establishing spillway capacity and top of dam. All spillways shall be designed to adequately handle debris either by trash racks or with sufficient opening. All dams shall have an overflow spillway included in the design. A constructed earthen embankment may not be used as an overflow spillway. All dams classed in Category I or II shall be designed with an emergency spillway which passes the inflow design flood without endangering the dam and whose predicted frequency of use is not greater than once in 100 years. Adequate provision shall be made to dissipate the energy of water flowing over or through the dam and to protect the downstream toe of the dam.

(5) Dams in Category IV. The designs, plans, and specifications for all dams not approved by the soil conservation district and classed in Category IV shall be reviewed by the Administration for technical compliance with the requirements in USDA, Natural Resource Conservation Service, Maryland Conservation Practice, Standard Pond Code 378 (January, 2000), which is incorporated by reference in COMAR 26.17.02.01-1B(2).

C. Design Specifications.

(1) Design References. References used by the designer shall be cited in the application submitted to the Administration, especially where unusual features are incorporated in the design.

(2) Freeboard. The design shall allow for certain freeboard as a minimum, not to be reduced under any circumstances during the operation of the dam and reservoir. The design freeboard is for that reservoir stage which will exist when the pool has reached maximum level during the inflow design flood with the outlet works and overflow spillway operating as planned. The freeboard is to be calculated to prevent overtopping and protect the dam against the destructive forces of waves, frost, settlement, and surface erosion.

(3) Safety Factor. The safety factor shall be that used in good engineering practice in dam design. In all important structural features, the safety factor used shall be shown in the design assumptions. The Administration requires a safety factor of at least 1.5 to be included in the structural design of the dam or any of its components during steady state seepage conditions, and at least 1.2 during rapid drawdown of the reservoir pool from the spillway crest. If site conditions or the downstream hazard category warrants, the Administration may require a safety factor of greater than specified in this section.

(4) Drains. Dams shall include a device to allow draining of the reservoir within a reasonable amount of time. The following factors shall be considered in determining the reasonable time period for drainage:

(a) The risk and nature of a potential dam failure;

(b) The time likely to be available to avert a failure after notice of conditions threatening the safety or stability of the dam; and

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

(5) Specifications. Specifications shall be written to assure that design criteria, with regard to the quality of the materials and methods of construction, will be met or exceeded.

(6) Providing Means for Inspections. The Administration may include, either at the time of granting a permit for construction of a dam or at a later date, a requirement that the owner provide and install devices necessary for the future inspection and surveillance of the dam. The number, type, and location of the devices shall be determined as a result of the Administration's evaluation of the size and nature of the dam, the complexity of local natural conditions, and the degree of risk resulting from any future deterioration or failure. The requirement may include provisions for the measurement of the settlement of the crest or slopes of dams, the movement of walls in the valley or reservoir, the increases in pore-water pressure in earth or the increases in flow from drainage systems, and the installation of other devices required to detect serious changes in the structure or the affected area to allow the repair of deficiencies before more serious risk develops.

(7) Multiple Dams. When dams are spaced so that the failure of an upstream dam or structure could endanger the safety of one downstream, the possibility of a multiple failure shall be considered in reviewing the design. Additional safety shall be provided in either structure by increasing the retarding storage or increasing the emergency spillway capacity, or both.

D. Construction Requirements.

(1) Construction shall be under the supervision of the engineer-in-charge as defined in §A(1) of this regulation.

(2) Appropriate tests, as required by the Administration, shall be made of materials used in the construction of the dam. Materials failing to meet applicable specifications shall be removed and replaced with acceptable materials.

(3) The engineer-in-charge shall submit periodic construction progress reports to the Administration. Progress report forms and the frequency of reporting will be provided by the Administration before construction.

(4) A history of the construction shall be maintained by the engineer-in-charge, and shall include:

(a) Date, location, and results of all materials tests made.

(b) Narrative of problems encountered during construction and changes in design. Necessity for these changes shall be reported to the Administration for approval before proceeding with construction.

(c) "As built" plans.

(5) The above information shall be maintained at the construction site. The information shall be submitted to the Administration within 60 days after the completion of the dam and shall be accompanied by the written certification from the engineer-in-charge to the Administration that the completed structure has been constructed in accordance with plans and specifications and changes approved by the Administration. The Administration shall supply certification forms.

(6) Before beginning the diversion of the streamflow through a temporary channel or conduit in order to dewater the foundation of the dam, the engineer-in-charge shall submit a plan to the Administration for approval describing the methods to be used for carrying the streamflow and keeping sediment reduced during this period. The engineer-in-charge shall be responsible for the implementation of the plan.

(7) Before beginning the filling of the reservoir the engineer-in-charge shall submit a report to the Administration stating that the structure has been made ready for filling and that the pool area has been cleared of debris. The report shall describe the limitations on the amount of water restrained from flowing downstream and describe the methods to be followed for the surveillance of the project during the period when the structure is receiving its initial loading.

E. Surveillance and Inspection of Completed Dams and Reservoirs.

(1) Responsibility for Inspections by Owner. The owner is responsible for the safety of the dam and for the necessary surveillance and inspections. The surveillance shall be performed by the owner, or a representative of the owner, and shall provide a close watch on the conditions affecting the dam's safety. The owner shall promptly notify the Administration of significant changes in condition.

(2) Responsibility for Inspections by Administration. In addition to the inspections by the owner, the Administration shall make inspections of all dams, reservoirs, and other waterway obstructions within its jurisdiction to provide for the public safety and welfare, to detect early signs of deterioration, and to enforce corrective measures. The Administration's agents shall be given free access to every part of the dam or reservoir under consideration, and the operators of these works shall assist in the inspection to the best of their abilities.

F. Repair of Dams. Before beginning the repair of any dam or reservoir, the owner shall apply for, in writing, and secure the Administration's written approval of the contemplated action. The application shall give the name and address of the applicant, details of the proposed changes, referenced to the existing structure, and shall be accompanied by the necessary plans and specifications. If the proposed work may best be explained by description, this description shall be included as part of the application along with the proposed time of commencement and completion of construction, as well as such other information as the Administration may require. In the event of an emergency in which repairs are necessary to safeguard life and property against predicted immediate danger, these repairs shall be made immediately by the owner. In these events, the Administration shall be notified within 24 hours of the emergency repairs needed and the extent of work underway, if any, and the work shall conform to these requirements as specified by the Administration.

G. Certain Small Ponds. Except for those ponds which are to be located in natural trout waters or those which are temporary and which are intended solely to trap sediment during construction operations, certain small ponds may be exempt from the permit requirements cited here if the plans and specifications are approved by the appropriate soil conservation district. The following shall apply to the approval of all ponds pursuant to Environment Article, §5-503(b), Annotated Code of Maryland:

(1) The plans and specifications shall be reviewed for technical compliance with the requirements in USDA, Natural Resource Conservation Service, Maryland Conservation Practice, Standard Pond Code 378 (January, 2000), which is incorporated by reference in COMAR 26.17.02.01-1B(2).

(2) The soil conservation district shall notify the Administration of all ponds approved pursuant to this section. The notification shall include a copy of the pond approval and a pond summary sheet. The notification shall be submitted to the Administration within 30 days of the end of each quarter (September 30, December 31, March 31, and June 30) in which the approval was granted.

(3) The soil conservation district, for all ponds approved pursuant to Environment Article, §5-503(b), Annotated Code of Maryland, shall submit a certification to the Administration within 90 days after the completion of construction. This certification shall state that the subject pond was constructed in conformance with the approved plans and specifications. A certification by a professional engineer, land surveyor, or landscape architect practicing in accordance with the laws of Maryland shall be acceptable to the Administration instead of a certification by the soil conservation district.