CSLB Land Development Engineering key terms

A state-mandated long-range policy document adopted by a city or county that designates land uses, circulation, housing, and open space, and which all subsequent zoning and development approvals must be consistent with.

A local law that implements the general plan by dividing land into districts and specifying permitted uses, lot coverage, setbacks, height limits, density, and parking requirements for each district.

A detailed planning and implementation document prepared for a defined geographic area, providing land use, infrastructure, and development standards more specific than the general plan but consistent with it.

The minimum horizontal distance required between a building or structure and a property line, street right-of-way, or other specified line, established by zoning to provide light, air, and separation.

The ratio of a building's total floor area to the area of the lot on which it sits, used by zoning codes to regulate building bulk and intensity of use independent of height.

The portion of a lot, usually expressed as a percentage, that may be covered by buildings or other impervious surfaces, limiting runoff increases and maintaining open area.

A preliminary subdivision map submitted for local approval showing lot lines, streets, easements, and improvements, which if approved leads to preparation of a final map for recording.

California law governing the division of land, setting procedures and standards for tentative, parcel, and final maps, and authorizing local agencies to impose subdivision conditions.

A subdivision map used for divisions creating four or fewer parcels, processed with less detailed review than a final subdivision map but still subject to local approval and improvement requirements.

A strip of land dedicated or acquired for public use, such as a street, alley, or utility corridor, within which roadway, sidewalk, and utility improvements are typically constructed.

A legal right granted to use a portion of another's property for a specific purpose, such as utility lines, drainage, or access, without transferring ownership of the land.

Large-scale earthmoving that establishes the overall site elevations, such as cutting hills and filling valleys, before precise finished grades for roads, pads, and drainage are set.

The final designed elevation of the ground surface after all grading is complete, shown on plans and used to set building pads, pavement, and drainage flow paths.

The process of excavating soil from high areas (cut) and placing it in low areas (fill) to achieve design elevations, ideally balanced on site to minimize hauling.

The point where the volume of cut material equals the volume of fill required, so no soil needs to be imported to or exported from the site.

Mechanical densification of soil by removing air voids, typically measured as a percentage of maximum dry density, to increase strength and reduce settlement under loads.

The ratio, expressed as a percentage, of a soil's in-place dry density to its laboratory maximum dry density determined by a standard test such as the Proctor test.

A laboratory test that determines the maximum dry density and optimum moisture content of a soil by compacting samples at varying moisture levels under standardized energy.

The moisture level at which a soil achieves its greatest dry density under a given compaction effort; soils are usually wetted or dried toward this value before compaction.

A phenomenon in which saturated loose sandy soils lose strength and behave like a fluid during earthquake shaking, potentially causing settlement, lateral spreading, and foundation failure.

Clay-rich soil that swells when wet and shrinks when dry, causing volume changes that can damage foundations, pavements, and utilities unless mitigated by design.

A site-specific engineering report describing subsurface conditions, groundwater, soil strength, settlement potential, and foundation and grading recommendations for design.

A prepared, graded, and compacted area of ground at design elevation on which a structure's foundation is constructed, typically extending beyond the footprint for drainage and access.

A street closed at one end by a circular or other turnaround, permitted only up to a maximum length, and required to provide adequate turning radius for fire apparatus and service vehicles.

The distance a driver needs to perceive a hazard and stop safely, determined by design speed, perception-reaction time, and braking friction, and used to set vertical and horizontal alignment.

The selected speed used to determine geometric features of a roadway, such as curve radii, superelevation, and sight distance, consistent with the intended function of the street.

A parabolic transition between two roadway grades that provides gradual change in slope, ensuring adequate stopping sight distance and comfortable vehicle operation.

The banking of a roadway cross section, with the outer edge raised above the inner edge on curves, to help counteract centrifugal force and improve vehicle stability.

The upward slope built into a roadway from the centerline to the edges, or from one edge to the other, to drain surface water off the pavement.

A profile representing the pressure head plus elevation head along a pipe system, used to confirm that water or sewage flows under gravity without exceeding pipe capacity.

The lowest inside elevation of a pipe or channel at a given cross section, used to establish gravity flow lines and drop connections at structures.

An underground access structure with a removable cover that allows inspection, maintenance, and connection of sewer or storm drain lines, typically placed at changes in alignment or grade.

A facility with pumps that raise wastewater or stormwater to a higher elevation when gravity flow to the receiving point is not feasible because of topography.

A pressurized pipe that conveys wastewater pumped from a lift station to a gravity system or treatment facility, designed for pressure flow rather than gravity flow.

A simple rainfall-runoff equation, Q = CiA, used to estimate peak stormwater flow from small drainage areas using a runoff coefficient, rainfall intensity, and drainage area.

The time required for runoff to travel from the most hydraulically remote point of a drainage area to the point of interest, used to select rainfall intensity in the Rational Method.

A facility that temporarily stores stormwater runoff and releases it at a controlled rate, reducing downstream peak flows and flood risk.

A stormwater facility that holds runoff permanently or allows it to infiltrate rather than discharging it, often used for water quality and groundwater recharge.

The downward movement of water from the ground surface into soil, used in stormwater design to reduce runoff volume and recharge groundwater where soils permit.

A surface such as pavement, concrete, or roofing that prevents water from infiltrating into the ground, increasing runoff volume and peak flow rates.

A structural or nonstructural measure used to control stormwater pollution, erosion, or sediment, such as swales, filters, basins, or construction-phase controls.

A temporary barrier of filter fabric supported by posts, installed along the downhill perimeter of disturbed areas to intercept sediment-laden runoff before it leaves the site.

A temporary or permanent pond that slows runoff so soil particles settle out before water is discharged, protecting downstream drainage and water bodies.

A site-specific plan required for construction and industrial activities that identifies pollution sources and specifies best management practices to prevent pollutants from reaching storm drains.

A federal permit program administered by states that regulates discharges of pollutants, including construction stormwater, into waters of the United States.

The primary federal law governing water pollution, establishing permit requirements for discharges and protecting surface water quality, including wetlands and stormwater.

A detailed document required under the California Environmental Quality Act that analyzes a project's significant environmental effects and identifies mitigation measures.

California law requiring public agencies to identify and disclose the environmental effects of proposed projects and to reduce or avoid significant impacts where feasible.

A project condition or design change adopted to avoid, minimize, rectify, reduce, or compensate for a significant environmental impact identified in an environmental review.

A recorded right allowing stormwater to flow across or be conveyed through a defined strip of private property, protecting the drainage path from obstruction.

A graph showing streamflow or runoff discharge over time at a point, used to evaluate peak flow, volume, and timing effects of development and detention.

The rate of water flow, typically in gallons per minute, required for firefighting at a given location, determined by building size, construction, and occupancy and provided by the water system.

A principal pipe in a distribution system that conveys potable water from sources and storage to service lines, sized to provide adequate pressure and fire flow.

The maximum distance permitted between fire hydrants along a street, set by fire code to ensure hose reach and adequate fire protection for adjacent buildings.

A device that lowers incoming water pressure to a safe, usable level for downstream plumbing and fixtures, protecting the system from excessive pressure.

An assembly installed in a water service line to prevent contaminated water from reversing into the potable supply because of pressure loss or cross-connection.