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Glossary of Terms

Adaptive Management: Modifications to the standards, conditions, mitigation measures, or monitoring requirements set forth in the original permit approval made by the permit authority in response to monitoring results, scientific analysis, changes in project setting and/or requirements to help meet program objectives and ensure that adverse impacts are avoided or minimized during the life of the permit.

Aggradation: Increase in the bed elevation of a stream channel from deposition of sediment.

Aggregate: Inert minerals or earth materials used as construction materials or base.

Alluvial: Pertaining to silt, sand, gravel, or similar material deposited by streams.

Ambient: Pertaining to the surrounding environment, particularly existing levels of activity or pollutants.

Anadromous: Pertaining to fish which migrate up streams from the sea to spawn e.g. salmon, steelhead.

Aquifer: Water-bearing strata of permeable rock, sand, or gravel.

Asphalt Concrete: Strong paving material consisting of aggregate and petroleum products, abbreviated AC.

Bank: Sloping ground bordering a stream channel which normally confines the water flow.

Bar: An alluvial deposit within a stream channel.

Batch plant: Aggregate processing operation producing separate lots or batches of AC or PCC.

Bioengineered Bank Stabilization: Approaches that utilize native woody vegetation combined structural or engineered stabilization measures.

Braided: Forming an interlacing network of multiple channels within the overall stream channel.

Channel: Bed or course of a stream through which the water flows.

Construction Aggregate: Aggregate used for PCC, AC, road base, or road sub-base.

Consumption Level of use or demand for aggregate products.

Cross-section Two-dimensional profile or picture of a stream channel, usually at right angles to the water flow or channel.

Cultural Resources Sites, structures, artifacts, and evidences of historic and pre-historic occupancy and use by humans and animals.

Decibel Unit on logarithmic scale used to measure relative intensity of sounds.

Degradation Decrease in the bed elevation of a stream channel.

Demand Estimated need for aggregate products.

Demographic Pertaining to statistical characteristics of human population.

Designation Title of official classification applied to a certain land area.

Endangered Pertaining to a plant or animal species designated as being in danger of extinction throughout a significant portion of its range.

Environment Existing physical conditions affected significantly by proposed project. (from CEQA).

Financial Assurance Bond, trust fund, letters of credit, or similar financial mechanism provided to government agencies to cover the costs of approved reclamation not performed by responsible party. (from SMARA).

Floodplain Area of alluvial deposits created by a stream and subject to inundation from the stream overtopping its banks. The area with an estimated probability of 1 percent of being inundated in any particular year is the "100-year" floodplain.

Geologic Formation Surface or sub-surface rock mass created in a different manner or time than adjacent masses.

Geomorphology Study of landforms on the earth's surface and the processes that create them.

Gravel Loose, rounded pieces of rock deposited and formed by alluvial action.

Groundwater Water in a saturated aquifer.

Habitat Sites where plants and animals naturally or normally live and grow.

Haul route Public and private roads used normally for hauling aggregate products to and from particular mining sites and processing operations.

Importation Act of bringing aggregate materials into a site from another separate site.

Impacts Direct and indirect effects of a project on the environment. (from CEQA)

Incision Degradation of a stream channel.

Instream Located within a stream channel.

Lead agency Public agency with primary responsibility for approving or carrying out a project. (from CEQA).

Level-of-Service Operational evaluation of roadway sectors which compares traffic volumes to estimated carrying capacities expressed in letters A through E, signifying a range from free-flowing conditions to congested conditions.

Longitudinal Profile or Gradient Slope of a stream channel parallel to the direction of water flow, as depicted by thalweg elevations along the channel.

Low-flow Channel Deepest portion of stream channel still carrying water when the total flow is at the lowest level.

Management Developing plans, establishing policies, assessing proposals, monitoring operations, enforcing standards, and other lead agency activities needed to fulfill SMARA requirements concerning the use of mineral resources.

Meander Bend of a stream channel where the longitudinal gradient is gentle and the floodplain is fairly level.

Mitigation Pertaining to actions which avoid, reduce, minimize, rectify, eliminate, or compensate for significant environmental impacts. (from CEQA)

Model Simulation or representation of a process or system.

Monitoring General Inspecting, observing, surveying, and reporting on aggregate operations and environmental conditions. From CEQA Lead agency activities to ensure compliance with approved mitigation measures.

Ordinary High-Water Mark Line on bank or shore of stream channel established by high water flows and indicated by changes in surface relief, soil, vegetation, and debris.

Portland Cement Concrete (PCC) Strong construction material consisting of aggregate, water, and powdered mixture of alumina, silica, lime, iron oxide, and magnesia.

Potential Pertaining to something which could develop or become actual.

Prime Agricultural Pertaining to land with surface soils of Class I or II. (from General Plan)

Production 1. Process of mining and transforming aggregate into usable materials, 2. Amounts of aggregate materials produced, sold, and used.

Production Sources Aggregate marketing area which supplies nearly all of its demand by within the area. (from California Department of Mines and Geology).

Program EIR EIR for a series of actions which can be characterized as one large project because they are geographically related, governed by a regulatory program, or have similar impacts which can be mitigated in similar ways. (from CEQA)

Project Activity undertaken or approved by a public agency which has a potential for resulting in physical change to the environment. (from CEQA)

Public Trust Easement Property interest of the State of California in land between ordinary low and high water levels along non-tidal navigable streams, said lands to be used for navigation, ports, harbors, commercial and recreational fisheries, boating and other water-oriented recreation, mineral resource development, open space, habitat preservation and enhancement, and other recognized public trust purposes. (from State Lands Commission).

Quarry Open earth excavation where rock and soil are extracted.

Reach A segment of stream length, especially a straight, wide, or level stretch between major topographical restrictions on the channel.

Recharge Natural restoration of materials, especially groundwater in an aquifer or sediment in a stream channel.

Recycling Process of recovering, collecting, and treating used materials to restore them for re-use or another use.

Reclamation Process of mitigating impacts of surface mining, especially residual hazards, so that mined lands are readily adaptable for alternate uses. (from SMARA)

Reserves Aggregate resources whose presence and feasibility of economic extraction is well supported by existing mining operations and/or sufficient geologic information.

Residual Pool Depth Means the difference between the elevation at the deepest part of the pool and the (lowest) elevation of the downstream riffle crest.

Resources Concentration of naturally occurring aggregate materials in such form and amount that economic extraction is currently or potentially feasible.

Riffle A topographic high point in a stream where the water flow is relatively shallow and fast and the water surface is broken by ripples or small waves.

Riparian Adjacent to, associated with, or otherwise dependent on a stream and its water flow.

Sand Loose, granular aggregate smaller than gravel and larger than silt.

Scenic Pertaining to picturesque landscapes, especially long or wide views from public roads.

Scenario Possible course of action or events.

Scoping Early consultation with affected agencies and other interested parties to identify alternatives, impacts, and mitigation to be addressed in an EIR. (from CEQA)

Sediment 1. Earth material picked up and deposited by water or wind, especially fine materials deposited by surface flows and slope erosion. 2. Gravel, sand, and silt transported and deposited by streams and forming such channels.

Sediment Budget Accounting or estimate of sediment or bed material transported, deposited and stored in a stream system or portion thereof.

Setback Minimum distance or space required between structures, mining excavation, processing facilities, property lines, stream channels, or other physical features.

Significant General Important or having weight, influence, or effect. From CEQA Potentially substantial and adverse, as in significant environmental impacts.

Skimming Removal of sand and gravel from gravel bars in stream channels above the water level of the low-flow channel.

Soil Association Category for classifying soil types regularly found together in a particular area.

Soil Class Rating of agricultural capabilities of soil types.

Spawning Production and deposition of eggs by fish in stream channel.

Streamway Corridor along a stream which includes the active channels, adjacent floodplain, and associated riparian vegetation and aquatic and wildlife habitat. The width of the streamway is based on geomorphic considerations and is intended to accommodate future changes as the river tends toward a dynamic equilibrium.

Terrace Level land areas of older alluvial deposits near a stream.

Thalweg Lowest elevation of a stream channel bed. On a longitudinal profile, the thalweg is indicated by the line connecting the lowest elevations.

Threatened Pertaining to plant or animal species designated as likely to become endangered in the foreseeable future.

Vested Right Established authority of surface mining operation to continue without new permits if it was legally and diligently commenced prior to January 1, 1976 and no substantial changes in operation are made.

Water Table Water surface or upper limit of groundwater.

Contact Information

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