Glossary of Terms
Beach
The sandy, pebbly, or rocky part of the shore of a body of water washed by the tide or waves.
Bioretention
The process in which contaminants and sediment are removed from runoff by collecting it into a ponding area consisting of a grass buffer strip, sand bed, organic layer, soil, and plants.
Biotreatment
The treatment of waste materials to remove pollutants or toxic substances through a biological process, such as using bacteria to remove contaminants.
BMPs (Best Management Practice)
Best management practice or device that helps to control, treat, or prevent runoff pollution.
Catch Basin
An inlet to a storm drain that includes some type of screening material, such as a grate, that helps to remove sediment and debris from entering storm drains.
Channels
Man-made basin which lets water flow and eventually drain into a river or other body of water.
Drainage Area
The land area where precipitation falls off into creeks, streams, rivers, lakes, and reservoirs.
Erosion
The process in which soil and rock are worn away or removed from a surface by the action of waterflow, wind, or physical means.
Estuaries
A coastal wetland created when salt water from the ocean mixes with nutrient-rich fresh water from inland sources.
Eutrophication
Excessive richness of nutrients in a lake or other body of water, frequently due to runoff from the land, which causes a dense growth of plant life and death of animal life from lack of oxygen.
Evapotranspiration
The process by which water is transferred from land to the atmosphere by evaporation from soil and evaporation of water from plant leaves (transpiration).
Green Roofs
A vegetative layer grown on a rooftop.
Green Waste
Biodegradable waste, such as branches, twigs, flowers, leaves, and grass clippings. Green waste includes all items that can be composted.
Groundwater
Groundwater is fresh water that soaks into the soil and is stored in the tiny spaces between rocks and particles of soil.
HHW (Household Hazardous Waste)
Household products that are flammable, corrosive, toxic, or can explode under certain circumstances.
Hydrologic
Relating to the science of water movement, distribution, quality, cycles, resources, and watersheds. Hydrologic character refers to the components that impact how water behaves in a certain area.
Illegal Discharge
Anything entering the storm drain system that is not rainwater, unless exempted by local ordinance.
Impermeable Surface
Impermeable surfaces are solid surfaces that don’t allow water to penetrate, forcing it to run off. Common impermeable surfaces include asphalt; concrete; and grouted stone, brick or concrete pavers.
Infiltration
The process of water entering the soil through rainfall and irrigation events.
IPM (Integrated Pest Management)
Long-term prevention of pests through a combination of techniques such as biological control, habitat manipulation, modification of cultural practices, and use of resistant varieties.
Irrigation Tune-Up
A test of a yard’s irrigation system to ensure water isn’t running off the property due to system leaks, misaligned or broken sprinklers, or unnecessary overwatering. Irrigation tune-ups are recommended to be conducted seasonally or every three months.
LID (Low Impact Development)
Refers to systems and practices that use or mimic natural processes that result in the infiltration, evapotranspiration, or use of stormwater to protect water quality and associated aquatic habitat. LID is an approach to land development (or re-development) that works with nature to manage stormwater as close to its source as possible.
MS4
Municipal Separate Storm Sewer System. A municipal conveyance system that collects and carries runoff that is not combined with the sewer system.
Mulch
Any material used as a covering to protect soil and surrounding plants, prevent weed growth, retain moisture, and reduce runoff pollution.
NPDES
National Pollutant Discharge Elimination System. The part of the Clean Water Act which requires point source discharges to obtain permits. NPDES permits are administered by the California Department of Natural Resources.
Ocean
A large body of salt water.
Permeable Surfaces
Surfaces which allow water to penetrate through and into the soil. Permeable surfaces filter out pollutants and recharge ground water sources.
Precipitation
Water released from clouds in the form of rain, hail, freezing rain, sleet, or snow.
Rain Garden
An area with adapted or deep-rooted native plants and grasses that collects rainwater runoff to infiltrate into the ground.
River
A large natural stream of water flowing in a channel to the sea, a lake, or another such stream.
Runoff
The flow of water over land that does not infiltrate into the ground.
Sanitary Sewers
Sanitary sewers carry raw sewage from homes and businesses to wastewater-treatment facilities.
Sewer Laterals
Sewer laterals are the pipes that carry wastewater from indoor plumbing fixtures like toilets‚ sinks‚ and dishwashers to the public sewer line under the street.
Source Control Measures
Elimination of pollutant sources through either product substitution or green chemistry.
Storm Drain
A structure that collects excess runoff from paved streets, parking lots, sidewalks, and roofs.
Stormwater
Water from rain events that runs off roofs, driveways, parking lots, yards, and other surfaces that does not absorb into the ground.
Structural Best Management Practices
Structural best management practices are facilities that help to prevent pollutants in runoff from leaving a developed property, entering our storm drains, and impacting our local waterways. Examples include detention basins and vegetated strips next to pavement.
total maximum daily loads
The maximum amount of a pollutant a waterway can contain while still meeting the state’s water quality standards.
Tree Box Filters
Mini bioretention areas installed beneath trees which helps to control stormwater runoff and filter out contaminants.
U.S. EPA
United States Environmental Protection Agency. A federal government agency that writes and enforces regulations based on laws passed by Congress to protect human health and the environment.
Water Quality Improvement Plan
Water Quality Improvement Plans include descriptions of the highest priority pollutants or conditions in a specific watershed, goals and strategies to address those pollutants or conditions, and time schedules associated with those goals and strategies.
Watershed
The land area that channels rainfall to creeks, streams, rivers, and eventually to reservoirs, bays, and the ocean. No matter where you live…you live in a watershed.
Watershed Divide
Elevated land (such as ridges, hills, or mountains) that forms a boundary to separate different watersheds, river systems, or drainage basins.
Wetland
Land or areas (such as marshes or swamps) that are covered, often intermittently, with shallow water or have soil saturated with moisture.