Unless the context otherwise requires, the definitions in this chapter govern the construction of this part.
Supervision of Dams and ReservoirsDefinitions
Section § 6000
This law section states that unless there is a specific reason not to, the definitions provided in the chapter should be used to interpret this part of the law.
definitions interpretation context requirements
Section § 6002
A "dam" in this context is any man-made structure that holds back or redirects water. It fits this definition if it is at least 25 feet high or can hold at least 50 acre-feet of water. The measurement considers the height from the streambed or the lowest point around it to where it can store water at maximum capacity.
“Dam” means any artificial barrier, together with appurtenant works, which does or may impound or divert water, and which either (a) is or will be 25 feet or more in height from the natural bed of the stream or watercourse at the downstream toe of the barrier, as determined by the department, or from the lowest elevation of the outside limit of the barrier, as determined by the department, if it is not across a stream channel or watercourse, to the maximum possible water storage elevation or (b) has or will have an impounding capacity of 50 acre-feet or more.
artificial barrier appurtenant works impound water
Section § 6002.5
This section defines a 'critical appurtenant structure' as a water-related structure that is either very tall at 25 feet or more, can hold a large amount of water, specifically 5,000 acre-feet or more, or is deemed dangerous by the department due to potential hazards downstream.
“Critical appurtenant structure” means a water surface barrier or hydraulic control structure that is 25 feet or more in height, that impounds 5,000 acre-feet of water or more, or that the department determines poses a significant downstream hazard potential.
critical appurtenant structure water surface barrier hydraulic control structure
Section § 6003
This law states that if a barrier is six feet tall or shorter, or if it can hold 15 acre-feet of water or less, it isn't classified as a dam. It doesn't matter how much the short barrier can hold or how tall the large-capacity barrier is.
Any such barrier which is or will be not in excess of six feet in height, regardless of storage capacity, or which has or will have a storage capacity not in excess of 15 acre-feet, regardless of height, shall not be considered a dam.
barrier height storage capacity dam classification
Section § 6004
This law outlines what is not considered a dam for regulatory purposes in California. Several structures, such as certain levees, non-stream channel barriers, and water impoundments for agriculture, are excluded. Specifically, it covers conditions for levees on lakes, small barriers in streams for water percolation, island levees in the Sacramento-San Joaquin Delta, and tanks used by public agencies under certain size limits.
It also defines conditions under which a regulating basin is not a dam, including specifications for barrier height, basin capacity, construction standards, and safety inspections. Regulating basins must meet specific safety and design criteria, be managed properly, and involve civil engineers in their planning and maintenance. If problems occur, appropriate channels, such as notifying local authorities, must be followed immediately.
(a)CA Water Code § 6004(a) An obstruction in a canal used to raise or lower water therein or divert water therefrom, a levee, including, but not limited to, a levee on the bed of a natural lake with the primary purpose to control floodwaters, a railroad fill or structure, a road or highway fill or structure, a circular tank constructed of steel or concrete, or both, a tank elevated above the ground, and a barrier that is not across a stream channel, watercourse, or natural drainage area and that has the principal purpose of impounding water for agricultural use shall not be considered a dam.
(b)CA Water Code § 6004(b) An obstruction in the channel of a stream or watercourse that is 15 feet or less in height from the lowest elevation of the obstruction and that has the single purpose of spreading water within the bed of the stream or watercourse upstream from the obstruction for percolation underground shall not be considered a dam.
(c)CA Water Code § 6004(c) The levee of an island adjacent to tidal waters in the Sacramento-San Joaquin Delta, as defined in Section 12220, even when used to impound water, shall not be considered a dam and the impoundment shall not be considered a reservoir if the maximum possible water storage elevation of the impounded water does not exceed four feet above mean sea level, as established by the United States Geological Survey 1929 datum.
(d)CA Water Code § 6004(d) A noncircular tank, constructed of steel or concrete, or both, that is constructed in a county of the third class by a public agency, under the supervision of a civil engineer registered in the state, that does not exceed 75 acre-feet in capacity or 30 feet in height, and a barrier that is not across a stream channel, watercourse, or natural drainage area and that has the principal use as a sewage sludge drying facility, shall not be considered a dam.
(e)Copy CA Water Code § 6004(e)
(1)Copy CA Water Code § 6004(e)(1) A regulating basin owned or operated by a public entity that is not across a stream channel, watercourse, or natural drainage shall not be considered a dam if all of the following criteria are met:
(A)CA Water Code § 6004(e)(1)(A) The barrier constructed to form the regulating basin has
a height of no more than 15 feet from the crest to the lowest downstream elevation where the barrier meets natural ground.
(B)CA Water Code § 6004(e)(1)(B) The regulating basin has a storage capacity of no more than 1,500 acre-feet.
(C)CA Water Code § 6004(e)(1)(C) The regulating basin, at the time of construction, does not have a downstream hazard classification of “high” or “extremely high,” based upon the department’s criteria for those determinations.
(D)CA Water Code § 6004(e)(1)(D) The regulating basin is designed, and its construction is overseen, by a licensed civil engineer.
(E)CA Water Code § 6004(e)(1)(E) The regulating basin is compliant with the general plan of the county in which it is located.
(2)CA Water Code § 6004(e)(2) In order for a regulating basin to qualify for the exclusion under paragraph (1), the owner
or operator of the regulating basin shall do all of the following:
(A)CA Water Code § 6004(e)(2)(A) Before the construction of the regulating basin, submit to the department an inundation map, stamped by a licensed civil engineer, identifying the flow and depth of water from the regulating basin in the event of a failure of a barrier constructed to form the regulating basin.
(B)CA Water Code § 6004(e)(2)(B) Undertake an inspection, conducted by a licensed civil engineer, of all barriers and all appurtenant structures of the regulating basin every two years following the regulating basin’s construction, and make the report available on the operating agency’s internet website.
(C)CA Water Code § 6004(e)(2)(C) Immediately upon the identification of a failure or the risk of failure of a barrier or works critical to the safe operation of the regulating basin, notify the county sheriff and local emergency
managers of all properties likely to be impacted by a failure, in accordance with the identification of those properties on the map submitted pursuant to subparagraph (A).
(f)CA Water Code § 6004(f) For purposes of this section, the following definitions apply:
(1)CA Water Code § 6004(f)(1) “Licensed civil engineer” means a civil engineer licensed pursuant to Chapter 7 (commencing with Section 6700) of Division 3 of the Business and Professions Code.
(2)CA Water Code § 6004(f)(2) “Natural drainage” means a land area over which seasonal precipitation or natural spring water accumulates and is channelized directly into a stream or watercourse.
(3)CA Water Code § 6004(f)(3) “Regulating basin” means a reservoir constructed to impound and manage the inflow and delivery of water for agricultural uses or for the purpose of groundwater recharge or other
actions undertaken to implement the Sustainable Groundwater Management Act (Part 2.74 (commencing with Section 10720) of Division 6).
flood control structures water management agricultural water impoundment
Section § 6004.5
This section defines a 'reservoir' as a body of water that is held back or will be held back by a dam.
“Reservoir” means any reservoir which contains or will contain the water impounded by a dam.
reservoir definition water containment dam impoundment
Section § 6005
This law defines who is considered an 'owner' of a dam or reservoir. An 'owner' includes the state, its departments, municipalities, public utilities, districts, individuals, and authorized agents or trustees. Courts may also appoint receivers or trustees as owners. Important to note, the United States government is not included as an 'owner' under this definition.
“Owner” includes any of the following who own, control, operate, maintain, manage, or propose to construct a dam or reservoir:
(a)CA Water Code § 6005(a)The state and its departments, institutions, agencies, and political subdivisions.
(b)CA Water Code § 6005(b) Every municipal or quasi-municipal corporation.
(c)CA Water Code § 6005(c) Every public utility.
(d)CA Water Code § 6005(d) Every district.
(e)CA Water Code § 6005(e) Every person.
(f)CA Water Code § 6005(f) The duly authorized agents, lessees, or trustees of any of the foregoing.
(g)CA Water Code § 6005(g) Receivers or trustees appointed by any court for any of the foregoing.
“Owner” does not include the United States.
dam ownership reservoir control state departments
Section § 6006
In this context, "alterations" and "repairs" refer specifically to changes or fixes that might impact the safety of a dam or reservoir.
“Alterations,” “repairs,” or either of them, mean only such alterations or repairs as may affect the safety of the dam or reservoir.
dam safety reservoir safety alterations
Section § 6007
This section defines 'enlargement' as any modification or addition to an existing dam or reservoir that increases the water storage level.
“Enlargement” means any change in or addition to an existing dam or reservoir, which raises or may raise the water storage elevation of the water impounded by the dam or reservoir.
enlargement dam modification reservoir modification
Section § 6008
This section defines 'water storage elevation' as the height the surface of the water would reach in a dam or reservoir when it is filled to capacity, assuming there is no water flowing out.
Water storage elevation means that elevation of water surface which could be obtained by the existing dam or reservoir, as previously operated, were there no outflow and were the reservoir full of water.
water storage elevation water surface elevation dam capacity
