RULE 138.00.90-003 - Rules Governing Design and Operation of Dams

RULE 138.00.90-003. Rules Governing Design and Operation of Dams

TITLE VII

RULES GOVERNING DESIGN AND OPERATION OF DAMS

SUBTITLE I. GENERAL PROVISIONS

Section 701.1 PURPOSE.

(a) Provide for the comprehensive regulation and supervision of dams for the protection of the health, safety, welfare and property of the citizens of Arkansas.

(b) Assure proper planning, design, construction, maintenance, monitoring and supervision of dams, including such preventive measures as are necessary to provide an adequate margin of safety.

Section 701.2 AUTHORITY. Rules governing design and operation of dams within the state of Arkansas are promulgated under authority of Subchapter 2 of Chapter 22 of Title 15 of the Arkansas Code of 1987.

Section 701.3 SCOPE OF REGULATIONS. All dams within the state of Arkansas, except those owned by the U.S. Army, Corps of Engineers or those exempted by Section 701.4, must have a valid construction and operation permit issued under the provisions of this title.

Section 701.4 EXEMPTIONS. Dams meeting either of the following criteria are not subject to rules contained in this title, unless the subtitle LX of this title is successfully invoked.

(a) Dams with height of dam less than 25 feet.

(b) Dams with normal storage capacity less than 50 acre-feet.

(c) Dams with crest elevations below the ordinary high water mark of the stream at that location.

Section 701.5 CONSTRUCTION PERMIT. A permit issued by the commission is required prior to construction of any dam not exempted under Sections 701.3 or 701.4 of this title.

Section 701.6 OPERATION PERMIT. Before water is deliberately impounded by closing drain gates, an operation permit must be issued by the commission. An operation permit will normally be issued by the Chief Engineer upon completion of final inspection and receipt of the Certificate of Substantial Compliance by the owner's engineer (see section 704.6).

Section 701.7 TRANSFER OF PERMIT. Within six (6) months after change of ownership of a permitted dam, the new owner shall notify the commission. The commission shall immediately issue a dam permit in the name of the new owner.

Section 701.8 DEFINITIONS. Unless clearly indicated by context, the following words and terms, when used in this Title, shall have meanings as defined herein:

(a) Certificate of Permit Approval - Certificate issued by Executive . Director stating that application for dam permit has been approved, and that construction will be authorized upon written approval of final plans and specifications by the Chief Engineer.

(b) Chief Engineer - The Deputy Director/Chief Engineer of the Soil and Water Conservation Commission.

(c) Commission - The Arkansas Soil and Water Conservation Commission.

(d) Construction cost - Estimated or actual material and labor costs, including excavation, embankment placement, spillways, gates, valves, and conduits. Shall not include costs of: land, reservoir clearing, engineering, water treatment facilities, or other costs not directly related to construction of the dam.

(e) Dam - Any barrier, including one for flood detention, designed to impound liquid volumes. This shall not include highway, railroad or other roadway embankments, including low water crossings that may temporarily detain floodwater, levees designed to prevent inundation by floodwater, or closed dikes to temporarily impound liquids in the event of emergencies.

(f) Effective crest of the dam - The elevation of the lowest point on the crest of the dam excluding spillways.

(g) Executive Director - The Executive Director of the Arkansas Soil and Water Conservation Commission.

(h) Existing dam:

(1) Any dam constructed prior to July 1,1957.

(2) Any dam constructed prior to November 20, 1990, in accord with rules of the commission in effect at the time of construction.

(i) Height of dam - The vertical distance from the effective crest of the dam to the lowest elevation on the downstream toe of the dam, including the natural stream channel.

(j) Maximum storage capacity - The volume of the impoundment created by the dam at the effective crest of the dam.

(k) Minimum release - Daily quantity of water which must be

(k) Minimum release - Daily quantity of water which must be released to preserve downstream riparian rights, permitted non-riparian rights or to meet instream water needs including, but not limited to those of fish and wildlife.

(L) Normal storage capacity - The volume of the impoundment created by the dam at the lowest uncontrolled spillway crest.

(m) Probable maximum flood "PMF" - The flood magnitude that may be expected from the most critical combination of meteorologic and hydrologic conditions that are reasonable possible for a given watershed.

(n) Probable maximum precipitation "PMP" - The greatest theoretical depth of precipitation for a given duration that is physically possible over a given size storm area at a particular geographical location at a certain time of the year. PMP values are to be determined from Hvdrometerological Report Number 51. Probable Maximum Precipitation For United States East of 105th Meridian.

(o) Proposed dam - Any dam, constructed or yet to be constructed, which is not included in the definition of existing dams.

(p) Spillway design flood "SDF" - The flood criteria that must be considered in design of a proposed dam.

(q) Spillway evaluation flood "SEF" - The flood criteria that must be considered in the hydrologic evaluation of an existing dam.

(r) Volume dam is designed to impound - For annual permit fee computation: the normal storage volume less storage designed to contain sediment accumulation over the life of the structure.

Section 701.9 DUTIES, OBLIGATIONS, AND LIABILITIES OF DAM OWNERS. Nothing in these rules shall be construed to relieve an owner or operator of a dam or reservoir of the legal duties, obligations or liabilities incident to ownership or operation.

Section 701.10 REGISTERED PROFESSIONAL ENGINEER. Preparation of all plans and specifications, and the construction, enlargement, alteration, repair or removal of dams subject to commission review shall be under the supervision of an engineer registered in this state or an authorized agent of the federal government.

Section 701.11 EXCEPTIONS. The commission may grant exceptions to requirements contained within this title if it is determined that such requirement is unnecessary due to the physical conditions involved. Any variance from these rules must be supported by a written approval by the commission's Executive Director setting forth the reason for its granting and the limits placed thereon.

Section 701.12 NO LIABILITY BY COMMISSION, EMPLOYEES, OR AGENTS. No action shall be brought against the state or the commission or its employees or agents for the recovery of damages caused by the partial or total failure of any dam or reservoir or through the operation of any dam or reservoir upon the grounds that the defendant is liable by virtue of any of the following:

(a) The approval of the dam or reservoir, or approval of flood-handling plans during construction;

(b) The issuance or enforcement of orders relative to maintenance and operation of the dam or reservoir;

(c) Control and regulation of the dam or reservoir;

(d) Measures taken to protect against failure during an emergency.

SUBTITLE II. FEES.

Section 702.1 INITIAL ESTIMATED APPLICATION REVIEW FEES. Any application for permitting a proposed dam after July 2, 1989 shall be accompanied by a check for one percent (1%) of the estimated construction cost of the dam or $100.00, whichever is greater, except that no application review fee shall exceed $500.00.

Section 702.2 FINAL COST REPORT. Within 45 days after completion of construction, the owner shall provide to the Commission a report of actual construction costs.

Section 702.3 FINAL APPLICATION REVIEW FEES. If fee computed on actual costs exceed fee computed on estimated costs by more than ten percent (10%), an additional application review fee must be paid to the Commission. The amount of the additional fee shall be the difference between the fee computed on the actual construction costs and the amount previously paid. In the event fees computed on actual costs are less than ninety percent of fee computed on estimated costs, the owner shall be refunded an amount equal.to the difference between the amount previously paid and the fee computed on the actual construction costs.

Section 702.4 ANNUAL PERMIT FEE. The annual permit fee shall be computed as specified in A.C.A. 15-22-219, as may be amended from time to time.

Excerpt from A.C.A. 15-22-219

Any person obtaining a permit under the provisions of 15-22-210 shall, in consideration therefor, pay to the commission a fee equal to five cents (5#) per acre-foot of water which the dam involved is designed to impound, but not less than twenty -five dollars ($25.00). The permit shall provide that the same fee shall be paid by that person to the commission each year thereafter during which the dam is maintained, on or before the anniversary date of the issuance of the permit.

SUBTITLE III. DESIGN AND EVALUATION OF DAMS

Section 703.1 CLASSIFICATION OF DAMS. All dams will be classified or reclassified as required to assure appropriate safety considerations. The three size classifications (small, intermediate, and large), based on height of dam and impoundment capacity, and the three hazard classifications (low, significant, and high), are combined to determine a dam's spillway design or evaluation flood. A dam's classification does not indicate the physical condition of a dam.

Section 703.2 'SIZE CLASSIFICATION CRITERIA. Size classification is based on the height of the dam or maximum reservoir storage capacity, and shall be in accordance with Table 1 of this section. Size classification is the most stringent category determined for either storage or height.

Table 1

SIZE CLASSIFICATION

CATEGORY

MAXIMUM STORAGE (ACRE-FEET)

HEIGHT (FEET)

Small

Less than 1000

Less than 40

Intermediate

Greater than or equal to 1000 and less than

50,000

Greater than or equal to 40 and less than 100

Large

Greater than or equal to 50,000

Greater than or equal to 100

Section 703.3 HAZARD CLASSIFICATION CRITERIA. Hazard potential classification shall be the most stringent classification based upon either potential loss of human life or economic loss in accord with Table 2 of this section.

Table 2 HAZARD POTENTIAL CLASSIFICATION

CATEGORY

LOSS OF HUMAN LIFE

ECONOMIC LOSS

Low

None expected (no permanent structures for human habitation)

Minimal (Undeveloped to occasional structures agricultural improvements.)

Significant

Possible, but not expected (a small number of inhabitable structures)

Appreciable (notable agricultural, industrial, or commercial development)

High

Expected (Urban development or large number of inhabitable structures).

Excessive (Extensive public, industrial, commercial, or agricultural development)

Section 703.4 HYDROLOGIC CRITERIA FOR DAMS.

(a) Hydrologic criteria contained in Table 3 are the minimum acceptable spillway design flood (SDF) for proposed dams as defined in section 701.8 of this title (definitions).

(b) Exceptions to Minimum Hydrologic Criteria - Minimum criteria may be reduced if properly prepared dam breach analyses show that dam failure during the spillway design flood would cause an increase in flood level of one foot or less at or downstream of the first inhabitable structure or financially significant development.

Table 3

HYDROLOGIC CRITERIA FOR DAMS

CLASSIFICATION HAZARD

SIZE

MINIMUM FLOOD

HYDROGRAPH Low (No. 3)

Small

Intermediate

Large

50 to 100 year freq. .25 PMF to .50 PMF .50 to .75 PMF

Significant (No. 2)

Small

Intermediate

Large

.25 PMF to .50 PMF .50 PMF to PMF PMF

High (No. 1).

Small

Intermediate Large .

; .50 PMF to PMF PMF PMF

NOTE: Where ranges are given in this table the minimum flood hydrograph shall be determined by straight line interpolation of rainfall, based upon the effective height of dam or maximum storage volume, whichever is greater.

Section 703.5 DOWNSTREAM RELEASES,

(a) Each dam constructed after the effective date of these regulations shall be equipped with a release port(s) designed to release a flow of water for instream uses and downstream riparian.

(b) Minimum release quantities shall be sufficient to maintain existing instream and offstream uses and shall be defined on a case by case basis after consideration of the best available low flow information. .

(c) Minimum release ports must be designed to operate without manual intervention.

Section 703.6 RESERVOIR DRAIN CONDUIT,

(a) All proposed dams must include a permanent facility for draining the reservoir.

(b) Such conduit shall have a minimum diameter of twelve (12) inches for watershed areas less than one square mile and eighteen (18) inches for watershed greater than one square mile. Such conduits must be capable of lowering the surface of the reservoir at a rate not less than two "2" inches per day (at normal pool) while inflow to the reservoir is twice the annual average daily flow.

(c) Operating equipment for the drain facility must be accessible from above the maximum design water surface, unless inlet design is such that conduit is flowing at capacity at a lower elevation.

Section 703.7 STRUCTURAL CRITERIA. All dams must be designed in accord with currently accepted engineering practice. Acceptable guidelines include those published and recommended by the U. S. Army. Corps of Engineers; U. S. Department of Agriculture, Soil Conservation Service; and U. S. Department of Interior, Bureau of Reclamation.

As a minimum, the design must address the following:

(a) Slope stability under all probable loading conditions.

(b) Stability against sliding and overturning.

(c) Adequacy of foundation for imposed loads.

(d) Adequacy of energy dissipating devices at discharge points.

(e) Adequacy of channels and conduits for expected flows

(f) Protection of embankments and other earth slopes from erosion.

(g) Stability against seismic forces for all "High Hazard" dams in seismic zones 2 and 3, and all "Significant Hazard" dams located in Seismic zone 3.

Section 703.8 EVALUATION OF EXISTING DAMS.

(a) Existing dams may be reevaluated if development of downstream areas warrant. Minimum acceptable spillway evaluation floods (SEF) shall be defined by Hydrologic criteria presented in Table 3 of this title. Overtopping during the SEF may be allowed if properly prepared analyses demonstrate that:

(1) overtopping will have a return interval greater than 25 years; and

(2) the dam would withstand the projected overtopping without failure. Dams not meeting minimum criteria are deemed below acceptable limits and are subject to necessary action under Subtitle VII of this title.

(b) Existing low hazard dams are exempt from hydrologic criteria given in Table 3, and other existing structures may be exempt if properly prepared dam breach analyses show that dam failure during the specified flood will result in a flood level increase of one (1) foot or less.

(c) Structural Evaluation - Evaluation of an existing structure shall include, but is not limited to: visual inspections and evaluations of potential problems such as leakage, seepage, cracks, slides, conduit control malfunctions and other structural and maintenance deficiencies which could lead to failure of a structure. An active and progressive deteriorating condition is sufficient for a finding that an existing dam is structurally inadequate.

Section 703.9 INTERIM ALTERNATIVES. At the time the commission considers the permanent upgrading or removal of an inadequate dam, the dam owner may request the commission to consider interim alternatives including but not limited to temporary repairs, reservoir dewatering, insurance coverage, and/or downstream warning and evacuation plans. Consideration shall be given to the time required to overcome economic, physical and legal restraints to upgrading, the prospect of permanent repair, current use of the facility, degree of risk and public welfare.

Section 703.10 EMERGENCY MANAGEMENT. The Executive Director may request, and/or the commission may order a dam owner to provide sufficient data to plan for potential effects of failure or malfunction of a dam and/or associated appurtenant facilities.

Section 703.11 VARIANCE. Upon request by the owner of an existing dam which does not meet the hydrologic criteria stated in Section 703.4 of this title, the Chief Engineer may authorize a variance from this criteria. The Chief Engineer's decision shall consider:

(a) consequences of dam failure,

(b) the owner's proposal for reduction of hazards,

(c) barriers to upgrading of the structure, and

(d) other pertinent factors.

SUBTITLE IV. CONSTRUCTION REQUIREMENTS

Section 704.1 PLANS AND SPECIFICATIONS. Written approval of plans and specifications must be obtained from the Chief Engineer prior to start of construction.

Section 704.2 CONSTRUCTION INSPECTION. An agent of the design engineer must be on site during construction to insure that techniques and materials used comply with plans and specifications.

Section 704.3 CONSTRUCTION RECORDS. The applicant (or applicant's engineer) must retain construction records throughout the life of the dam. As a minimum, the records must include:

(a) Daily log of construction activities

(b) Record of personnel and equipment on site.

(c) Documentation of soil tests such as standard proctor, in-place density, and moisture.

(d) Documentation of concrete cylinder tests.

(e) Copies of all engineering change orders and field change notes.

Section 704.4 EROSION PROTECTION. During construction, adequate measures must be taken to prevent excessive erosion and off site sedimentation. Suitable techniques include: temporary vegetation, mulching, staked straw bales, filter fences, and chemical stabilization. Other techniques may be used if approved by the Chief Engineer.

Section 704.5 FINAL INSPECTION. Upon substantial completion of construction, the owner must notify the commission and schedule a final inspection of the work.

Section 704.6 ENGINEER'S CERTIFICATION. Upon completion of construction, the project engineer shall file with the commission^ certificate of substantial compliance with approved plans and specifications.

Section 704.7 RECORD DRAWINGS. Within sixty (60) days after completion of construction, the owner, or his engineer shall submit to the Chief Engineer a complete set of record drawings of the project for filing with the permanent records of the commission.

Section 704.8 PERMANENT REFERENCE MARKS. Two or more permanent reference mark(s) shall be established for future use near but separate from the dam. Accurate location(s) and elevation(s) above mean sea level shall be shown on the record drawings.

SUBTITLE V. OPERATION AND MAINTENANCE

Section 705.0 COMPLIANCE WITH APPROVED DOCUMENTS.

Operation and maintenance must be carried out in accord with documents filed by the owner or owner's engineer in obtaining the dam permit.

Section 705.1 EROSION PROTECTION. Maintenance of adequate means to protect embankments, abutments, and earthen channels from erosion is required. -

Section 705.2 WOODY VEGETATION PROHIBITED. Growth of woody vegetation is not permitted in the following locations:

(a) Spillways

(b) Upstream or downstream embankments

(c) Within 20 feet of the downstream toe or abutments of dams or dykes

(d) Crest of dam or dyke

Section 705.3 VEGETATION PROHIBITED ON CONCRETE OR MASONRY STRUCTURES. No grass, vines, bushes, trees or other vegetation is permitted to grow in cracks or joints of concrete or masonry structures.

Section 705.4 OPERATION OF GATES AND CONTROLS. All gates, valves and controls, including drain gates must be maintained in operational condition. Operation of each such item must be tested at least annually, and such tests must be documented in the owner's permanent records.

Section 705.5 REPAIRS AND MODIFICATIONS. Written .

approval by the Chief Engineer is required before repairs or modifications to the dam or appurtenances may be undertaken. Plans and specifications prepared by a registered professional engineer may be required for major actions.

Section 705.6 RECORDS. Owner must retain, for the life of the structure, documentation of all owner's inspections, and repairs or modifications to the dam or appurtenances.

SUBTITLE VI. INSPECTION

Section 706.1 OWNER'S INSPECTION. At least once per year and after each major storm event, the owners of High hazard potential dams (or owner's agent) must perform a visual inspection of the dam. Any deterioration of the dam or appurtenances must be reported to the commission, and remedial measures undertaken after approval by the Chief Engineer.

Section 706.2 COMMISSION INSPECTION. Commission personnel will periodically perform inspections of each permitted dam. Routine commission inspections are of two types:

a) Maintenance and Operation;

b) Dam Safety Evaluation. The frequency of these inspections will vary according to the hazard rating, size and condition of the dam. Emergency inspections will be performed when conditions warrant.

Section 706.3 ACCESS. The owner or owner's agent must provide commission personnel access to the dam during reasonable working hours for routine inspections. Access during emergency conditions must be available to commission personnel.

Section 706.4 ASSISTANCE BY OWNER. The owner or owner's agent may be requested to provide limited assistance to commission personnel in performing inspections. Requested assistance may include:

(a) Operating gates, valves and other controls.

(b) Cutting excessive vegetation in preparation for Dam safety evaluations (not for routine operation and maintenance inspections).

SUBTITLE VII. ENFORCEMENT

Section 707.1 NOTICE OF NON EMERGENCY DEFICIENCY.

Upon discovery of a deficiency, which does not immediately threaten the dam's safety, the Chief Engineer will issue a letter specifying actions necessary to remedy the problem and requesting a timetable for implementing the required actions. Upon receipt and acceptance of a timetable, a consent order will be issued which will embody the agreed upon actions and timetable.

Section 707.2 EMERGENCY REMEDIAL ORDERS. Upon discovery of a condition which renders a dam subject to rapid failure, the Executive Director may issue an Emergency Remedial Order describing actions which must be taken to protect life and property.

Section 707.3 PUBLIC HEARINGS. In the event remedial measures cannot be accomplished through the means of consent orders, the Executive Director shall cause a public hearing to be conducted to present the staffs proposed order and accept testimony. The hearing shall be conducted in the county in which the dam is located. Public notice of the hearing shall be provided in a manner consistent with Section 708.6 of this title.

Section 707.4 COMMISSION ORDERS. After review of findings of the public hearing, the commission may issue orders compelling specified actions.

Section 707.5 PENALTIES. Persistent non compliance with commission rules or disregard of commission orders may result in fines of up to $10,000. In general penalties will be set by doubling the costs incurred by the commission.

Section 707.6 APPEALS. Actions by the commissions may be appealed as described in Subtitle V of Title I Rules of Organization and General Operation of the Arkansas Soil and Water Conservation Commission.

SUBTITLE VIII APPLICATION PROCEDURE.

Section 708.1 APPLICATION FORM Applicants for permits for proposed dams must provide all applicable information requested on the form supplied by the commission. Applicants for permits for existing dams may omit information marked as "optional" if not available.

Section 708.2 COMMISSION REVIEW. Upon receipt of application for dam permit, the commission staff will undertake a comprehensive review of data presented to ascertain compliance with engineering practice, state law, and commission rules.

Section 708.3 WATER PLAN COMPLIANCE. Filing of an application to permit a proposed dam also serves as filing for Water Plan Compliance Certification as described in Section 602.5 of the commission's rules. The water plan compliance process may run concurrently with the dam permit review.

Section 708.4 PUBLIC NOTICE. Upon completion of staff review, and satisfaction of any deficiencies, the Executive Director will cause a Public Notice to be published two times, one week apart. The Public Notice will be placed in a newspaper having general circulation in the county in which the dam is located. Information in the public notice will include: the owner's name and address, the dam's location, pertinent physical data describing the dam, and the proposed action of the commission. In addition, the public notice will request that comments or objections to permitting be forwarded to the commission offices.

Section 708.5 CERTIFICATE OP PERMIT APPROVAL. If no comments or objections have been received at the end of a twenty (20) day waiting period after the second printing of the notice, the Executive Director will issue a certificate of permit approval or notification of denial.

Section 708.6 PUBLIC HEARING. If so requested, the Executive Director shall cause a public hearing to be conducted within the county in which the dam is located. Said hearing will be for the purpose of describing the proposed actions and taking testimony regarding the public view of the proposal. The Executive Director shall cause publication of public notice describing the time, place and purpose of the Public Hearing. Copies of the public notice shall be furnished to the owner, complainant(s) adjacent landowners (if known). Publication shall be in a newspaper having general circulation in the county in which the dam is located. Notice shall be printed twice, one week apart, and the hearing shall follow the second printing.

Section 708.7 COMMISSION ACTION. After consideration of testimony and documents presented at a public hearing, the commission may direct the Executive Director to issue or deny a Certificate of Permit Approval.

SUBTITLE IX HIGH HAZARD DAMS - UNDER MINIMUM SIZE LIMITS

Section 709.1 PETITION BY AFFECTED PERSONS. Persons who believe themselves or their property endangered by failure of a dam which is below the size requirements specified in section 701.4 may file a petition requesting that the commission require permitting and compliance with dam safety regulations for that dam.

Section 709.2 COMMISSION INVESTIGATION. Upon receipt of such petition, the Executive Director shall immediately begin an investigation of the petitioner's, allegations.

Section 709.3 PUBLIC HEARING. As apart of the commission's investigation, a public hearing shall be held within the county in which the dam is located. Notice of the hearing shall be published in a manner consistent with section 708.6.

Section 709.4 COMMISSION ORDER. Upon consideration of staff findings and testimony received, the commission shall issue an order either approving or denying the petitioner's request.

SUBTITLE X REMOVAL OF DAMS

Section 710.1 APPROVAL OF PLANS REQUIRED. Prior to removal, a plan for removal and revegetation must be approved by the Chief Engineer.

Section 710.2 PROCEEDURE FOR BREACHING. The proceedure for breaching must adequately guard against downstream flooding, erosion, and sedimentation.

Section 710.3 RESTORATION OF ORIGINAL STREAM CHANNEL. Dimensions of the final cut through the dam must be defined in the plan and must be of sufficient size to prevent impounding water when stream flow equals the 100 year flood.

Section 710.4 EROSION PROTECTION. The plan must provide for establishment of vegetation or other erosion protection means sufficient to guard against deposition of excessive sediment off site.

(12/10/1990)

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