Dam Safety

Del. Code tit. 7, ch. 42
in effect

Del. Code tit. 7, § 4201 Purpose.

It is the purpose of this chapter to provide for the proper design, construction, operation, maintenance and inspection of dams in the interest of public health, safety, and welfare, in order to reduce the risk of failure of dams and to prevent injuries to persons, damage to downstream property and loss of reservoir storage.

Del. Code tit. 7, § 4202 Definitions.

The following words, terms and phrases, when used in this chapter, shall have the meanings ascribed to them except where the context clearly indicates a different meaning: (1) “Dam” shall mean any artificial barrier, including appurtenant works, with the ability to impound or divert water, wastewater, or liquid-borne materials. (2) “Department” shall mean the Department of Natural Resources and Environmental Control. (3) “Emergency action plan” shall mean a plan prepared by the dam owner and approved by the Department which identifies emergency conditions at a dam and specifies preplanned actions to minimize loss of life and property damage in the event of a potential dam failure. (4) “High hazard potential dam” shall mean any dam whose failure or misoperation will cause probable loss of human life. (5) “Low hazard potential dam” shall mean any dam whose failure or misoperation is unlikely to cause loss of human life but may cause minor economic and/or environmental losses. (6) “Maximum storage elevation” shall mean the elevation of the lowest point of the top of dam independent of low points caused by partial failure or collapse. (7) “Owner” shall include any of the following who own, control, operate, maintain, manage, or propose to construct, reconstruct, enlarge, repair, alter, remove or abandon a dam or reservoir: the State and its departments, institutions, agencies and political subdivisions; every municipal or quasi-municipal corporation; every public utility; every district; every person; the duly authorized agents, lessees, or trustees of any of the foregoing; and receivers or trustees appointed by any court for any of the foregoing. (8) “Person” shall mean any person, firm, association, organization, partnership, business trust, corporation or company. (9) “Reservoir” shall mean any basin that contains or will contain impounded water, wastewater, or liquid-borne materials by virtue of its having been impounded by a dam. (10) “Secretary” shall mean the Secretary of the Department of Natural Resources and Environmental Control. (11) “Significant hazard potential dam” shall mean any dam whose failure or misoperation will cause possible loss of human life, economic loss, environmental damage, disruption of lifeline facilities, or can impact other concerns. (12) “State” shall mean the State of Delaware. (13) “Supervising engineer” shall mean the design engineer who is responsible for conducting dam construction quality assurance inspections in order to certify the construction has been completed in accordance with the approved plans and specifications.

Del. Code tit. 7, § 4203 Application.

(a) This chapter shall apply to any dam which is owned by the State or any county in the State, or any municipality or any quasi-governmental agency of the State that is 25 feet or more in height from the natural bed of the stream or watercourse measured at the downstream toe of the barrier or from the lowest elevation of the outside limit of the barrier, or if it is not across a stream channel or watercourse, measured at maximum water storage elevation; or any dam having an impounding capacity, at maximum storage elevation, of 50 acre-feet or more; or any dam that is deemed by the Secretary to be a significant or high hazard potential structure due to its location or other physical characteristics. (b) This chapter shall not apply to any dam that is not in excess of 6 feet in height regardless of storage capacity, or any dam having a storage capacity at maximum water storage elevation not greater than 15 acre-feet regardless of height, or any low hazard potential dam constructed prior to the effective date of this legislation, unless deemed by the Secretary to be a significant or high hazard potential structure due to its location or other physical characteristics. (c) This chapter shall not apply to any private owner of a dam unless such owner executes a document with the Department requesting such coverage.

Del. Code tit. 7, § 4204 Construction of dams.

(a) No owner shall begin the construction of any dam to which this chapter applies without written approval from the Department. Owners intending to construct any dam to which this chapter applies shall file with the Department a preliminary application which shall include a dam break analysis, the dam height, the maximum impounding capacity, purpose, location and determination of hazard class, and other information required by the Department. If on the basis of this information it is the opinion of the Department that the proposed dam is exempt from the provisions of this chapter, it shall notify the owner that no approval from the Department is required. If on the basis of the submitted information it is the opinion of the Department that the proposed dam is not exempt, the Department shall notify the owner that construction shall not be commenced until a full application has been filed by the owner and such application approved in accordance with §§ 4206 and 4209 of this title. The Department shall require emergency action plans and operation and maintenance plans for high or significant hazard potential dams, and may also require of owners so notified the filing of any additional information it deems necessary, including, but not limited to, streamflow and rainfall data, maps, plans, and specifications. Every owner applying for approval of a dam subject to the provisions of this chapter shall also file with the Department a Certificate from a qualified professional engineer, licensed in the State. The Certificate should state that the engineer is qualified and responsible for the design of the dam; that the design is safe and adequate; and that the engineer shall be responsible for construction quality assurance to certify that the construction has been completed in accordance with the approved plans. (b) The Department shall send a copy of each completed application to the Delaware Emergency Management Agency and other state, federal and local agencies it considers appropriate for review and comment. (c) Upon receipt of a full application in proper form, the Secretary shall give notice in the form of an advertisement in a newspaper of general circulation in the county in which the activity is proposed and in a daily newspaper of general circulation throughout the State: (1) The fact that the application has been received; (2) A brief description of the nature of the application; (3) The place at which a copy of the application may be inspected; and (4) Procedures to request a public hearing. The Secretary shall hold a public hearing on an application, if the Secretary receives a request from any party whose interests are substantially affected by the proposed application, as determined by the Secretary, if such request is received within 21 calendar days of the public notice. Such notice shall also be sent by mail to any person who has requested such notification from the Department and provides a name and address.

Del. Code tit. 7, § 4205 Repair, alteration, or removal of dams.

(a) Before commencing the repair, alteration or removal of any dam to which this chapter applies, application shall be made by the owner for written approval by the Department, except as otherwise provided by this chapter. The application shall state the name and address of the owner, shall adequately detail the changes it proposes to affect, impacts or modifications to plans of operation and maintenance and emergency action plans, and shall be accompanied by maps, plans, and specifications setting forth such details and dimensions as the Department requires. The Department may waive the requirements of this section for the repair or alteration of a dam if the proposed action is determined to be minor as defined by the Department by regulation. The application shall give such other information concerning the dam and reservoir required by the Department, such information concerning the safety of any change as it may require, and shall state the proposed time of commencement and completion of the work. When the Department determines an application has been completed it may be referred by the Department for agency review and report, as provided by § 4204 of this title in the case of original construction. The application for repair, alteration or removal of the dam shall be subject to the public notice requirements. (b) Upon receipt of a full application in proper form, the Secretary shall give notice in the form of an advertisement in a newspaper of general circulation in the county in which the activity is proposed and in a daily newspaper of general circulation throughout the State: (1) The fact that the application has been received; (2) A brief description of the nature of the application; (3) The place at which a copy of the application may be inspected; and (4) Procedures to request a public hearing. The Secretary shall hold a public hearing on an application, if the Secretary receives a request from any party whose interests are substantially affected by the proposed application, as determined by the Secretary, if such request is received within 21 calendar days of the public notice. Such notice shall also be sent by mail to any person who has requested such notification from the Department and provides a name and address. (c) When repairs are necessary to safeguard life and property they may be started immediately, but the Department shall be notified as soon as practical but no longer than 24 hours after such repairs have commenced. The owner shall be required to submit as-built plans and certification from a professional engineer, licensed in Delaware, demonstrating that the repairs comply with this chapter.

Del. Code tit. 7, § 4206 Actions by the Department upon applications.

(a) Public notice of application shall consist of an advertisement in a newspaper of general circulation in the county in which the activity is proposed and in a daily newspaper of general circulation throughout the State to include the fact that the application has been received, a brief description of the nature of the application and the place at which a copy of the application may be inspected: (b) Following the receipt of requested comments the Department shall approve, disapprove, or approve subject to conditions necessary to ensure safety all applications pursuant to this chapter. (c) A defective application shall not be rejected but notice of the defects shall be sent to the owner. If the owner fails to file a perfected application within 30 days of the date of the notice the original shall be canceled unless further time is allowed. (d) If the Department disapproves an application, 1 copy shall be returned with a statement of its objections. If an application is approved, the approval shall be attached thereto, and a copy returned. Approval shall be granted under terms, conditions, and limitations which the Department deems necessary to safeguard life and property. (e) Construction shall be commenced within 2 years after the date of approval of the application and completed within 5 years of commencement of construction or the approval is void. The Department upon written application and good cause shown may extend the time for commencing construction or for completing the construction. Notice by registered or certified mail shall be given the Department at least 10 days before construction is commenced.

Del. Code tit. 7, § 4207 Fees.

(a) The Department may establish an application fee not to exceed $500. (b) Any fees collected under this chapter are hereby appropriated to the Department to carry out the purposes of this chapter. The Secretary shall report through the annual budget process the receipt, proposed use and disbursement of these funds.

Del. Code tit. 7, § 4208 Rules.

The Secretary shall develop and adopt regulations and standards in conjunction with a regulatory advisory committee, appointed by the Secretary, which include public and private dam owners, as well as appropriate state and federal agencies, conservation districts, and other governmental subdivisions of the State. Dam safety regulations and standards shall include but not be limited to definitions, permit-by-rule, general requirements and prohibitions, application procedures, dam classification, design criteria, construction requirements, operation and maintenance requirements and inspection requirements.

Del. Code tit. 7, § 4209 Supervision by qualified engineers; reports and modifications during work.

(a) Any project for which the Department’s approval is required under §§ 4204, 4205 and 4206 of this title and any project undertaken pursuant to an order of the Department issued pursuant to this chapter or § 4212 of this title shall be designed and the construction supervised by a licensed professional engineer in the State with related experience in dam design and construction. (b) During the construction, enlargement, repair, alteration, or removal of any dam to which this chapter applies, the Department may require such progress reports from the supervising engineer responsible for design and construction quality assurance, as it deems necessary. (c) If, based on inspection reports, construction inspections or other information, the Department finds that the work is not in compliance with the provisions of the approval and the approved plans and specifications, it shall give written notice to the person who received the approval and to the person in charge of construction of the dam. The notice shall state the particulars in which compliance has not been made, and shall order immediate compliance with the terms of approval, and the approved plans and specifications. The Department may order that no further construction work be undertaken until such compliance has been effected and approved by the Department. A failure to comply with the approval and the approved plans and specifications shall render the approval revocable unless compliance is made after notice as provided in this chapter.

Del. Code tit. 7, § 4210 Notice of completion; certification of final approval.

(a) Within 7 days of completion of construction, reconstruction, enlargement, repair, alteration or removal of any dam to which this chapter applies, notice of completion shall be given to the Department. Within 60 days thereafter supplementary drawings or descriptive matter showing or describing the dam as actually constructed in compliance with the approval and the approved plans and specifications shall be filed with the Department in such detail as the Department may require. (b) Upon completion of the project, the supervising engineers, having inspected the work during construction and upon finding that the work has been done as required and that the dam is safe, shall file with the Department a certificate and as-built plans demonstrating that the work has been completed in accordance with the approved design plans, specifications, and other requirements. After review of the supervising engineer’s certificate and as-built plans, unless the Department has reason to believe that the dam is unsafe or is not in compliance with any applicable rule or law, the Department shall grant final approval of the work in accordance with the certificate, subject to such terms as it deems necessary for the protection of life and property. (c) Pending issuance of the Department’s final approval, the dam shall not be filled except on written consent of the Department, subject to conditions it may impose.

Del. Code tit. 7, § 4211 Operation and maintenance of dams.

The Department shall require that dam owners and operators develop, use and update as necessary an operation and maintenance plan which provides guidance and instruction to personnel for the proper operation and maintenance of any reservoir or dam to which this chapter applies to safeguard life and property. The operation and maintenance plan shall be subject to the approval of the Department and may be reviewed, modified or amended by the Department as deemed necessary to safeguard life and property. The Secretary may adopt, amend, modify or repeal standards for the maintenance and operation of dams as may be necessary for the purposes of this section. The Department may vary the standards applicable to the various dams giving due consideration to the type and location of the structure, the hazards to which it may be exposed, and the peril of life and property in the event of a failure or misoperation of the dam.

Del. Code tit. 7, § 4212 Inspection of dams.

The Department shall require regular inspection of any dam to which this chapter applies to safeguard life and property. The Secretary may adopt, amend, modify or repeal standards for the inspection of dams as may be necessary for the purposes of this section. The Department may vary the standards applicable to the various dams giving due consideration to the type and location of the structure, the hazards to which it may be exposed, and the peril of life and property in the event that a dam fails to perform its function. The Department shall inform the Delaware Emergency Management Agency of any dam presenting a risk of peril of life and property in the event that the dam fails.

Del. Code tit. 7, § 4213 Appeals.

(a) Except as otherwise provided in this chapter, any action or determination by the Department under this chapter shall be subject to appeal to the Environmental Appeals Board in accordance with the provisions of § 6008 of this title. (b) Appeals of decisions by the Environmental Appeals Board shall be conducted pursuant to § 6009 of this title.

Del. Code tit. 7, § 4214 Investigations by the Department.

The Department shall make investigations and assemble such data as it deems necessary for a proper review and study of the design and construction of any dams, reservoirs and appurtenances to which this chapter applies, and for such purposes the Department or its agents may enter upon private property. The Department may employ or make such agreements with geologists, engineers, or other expert consultants and such assistants, as it deems necessary to carry out the provisions of this chapter.

Del. Code tit. 7, § 4215 Liability for damages.

No action shall be brought against the State, the Department, or any agent of the Department or any employee of the State or the Department for damages sustained through the partial or total failure of any dam, misoperation or its maintenance by reason of any supervision or other action taken pursuant to or under this chapter. Nothing in this chapter shall relieve an owner or operator of a dam from the legal duties, obligations and liabilities arising from such ownership and operation.

Del. Code tit. 7, § 4216 Enforcement procedures.

(a) Any person who violates any rule, regulation, order, or condition imposed in an approved document or other provision of this chapter shall be fined not less than $200 or more than $2000 for each offense. Each day that the violation continues shall constitute a separate offense. The Justice of the Peace Courts shall have jurisdiction of offenses brought under this subsection. (b) Any person who intentionally, knowingly, and after written notice to comply, violates any rule, regulation, order, or condition imposed in an approved document or other provision of this chapter shall be fined not less than $500 or more than $10,000 for each offense. Each day the violation continues shall constitute a separate offense. The Superior Court shall have jurisdiction over offenses brought under this subsection.

Del. Code tit. 7, § 4217 Rights of investigation, entry, access, inspection and protective action.

(a) The Department shall have the right to direct the conduct of such investigations as it may reasonably deem necessary to carry out its duties prescribed in this chapter and the Department shall have the right to conduct such investigations, and for the purpose of inspections the employees of the Department and agents of the Department have the right to enter at reasonable times on any property, public or private, for the purpose of investigating the condition, construction or operation of any dam or associated equipment facility or property, and to require written statements or the filing of reports under oath, with respect to pertinent questions relating to the construction or operation of any dam. No person shall refuse entry or access to any authorized representative of the Department who requests entry for purposes of inspection, and who presents appropriate credentials, nor shall any person obstruct, hamper or interfere with any representative while in the process of carrying out that representative’s official duties. (b) Notwithstanding any other provisions of this chapter, the Department, upon receipt of information that any dam may present an imminent and substantial hazard to the public health, safety or welfare, may take such actions as it determines to be necessary to protect the public health, safety or welfare. The Department may direct the owner or custodian of the dam to take such actions as are necessary to prevent, eliminate or reduce the hazard. In the event the owner or custodian fails to take such actions, the Department shall have the right to take all appropriate or necessary action including, but not limited to, breaching or draining. The Department may initiate legal proceedings to recover the emergency costs from the dam owner.
Source: DE Code (Official Site)URL: https://delcode.delaware.gov/title7/c042/index.htmlFetched: 6/28/2026

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Del. Code tit. 7, ch. 42 — Dam Safety | Delaware Code — Delaware | Corpus