Glossary: Words and Phrases
Source: Public Policy Institute of California
Adaptive Management-A flexible, learning-based management approach in which natural systems are managed to ensure their recovery and improvement, while an understanding of how these systems function is developed to raise the effectiveness of future management actions.
Anadromous Fish Species-Fish that live in ocean water and move inland to spawn, such as salmon.
Consumptive Water Use-Diversions of water withdrawn but not returned downstream.
Desirable Fish Species-Fish with at least two of the following attributes:
(a) listed as threatened or endangered, or proposed for listing, under state or federal Endangered Species Acts;
(b) support an important sport or commercial fishery;
(c) endemic or native;
and (d) dependent on the estuary to complete their life cycle, either by living there or migrating through it.
Cumulative Probability-The total probability over a range of values or time periods.
Electrical Conductivity-A surrogate measurement for salinity in water.
Environmental Water-Water allocated to support fish and aquatic habitat, often through minimum flow requirements.
Estuary-A semi-enclosed embayment where saltwater is significantly diluted by fresh water from inflowing rivers.
Export Diversions-Water diverted from the Delta watershed for use in areas to the west and south of the Delta.
Export Pumps-Pumps used for water exports, primarily in the southern Delta.
Fish Entrainment-The drawing of fish or fish larvae into pumps or water diversions.
Ground Acceleration-A measure of intensity of shaking during an earthquake, often described as proportional to the acceleration due to gravity.
Hydraulic Factors-Water movement's effects on biological and physical processes.
Hydrologic Conditions-Conditions related to water inflows.
Hydrodynamic-The physics of water movement and the movement of matter (e.g., sediment, salts) in the water.
Inflows-Natural or managed flows of water into a particular location.
Land Subsidence-The sinking of lands caused by compaction, oxidation of peat soils, and wind erosion. Many Delta islands have subsided (mostly from oxidation and erosion) to the point where they now lie many feet below sea level.
Minimum Flow requirements-Water flows required by regulators, typically for environmental purposes.
Mitigation-An action intended to moderate some effects of other activities. For instance, flood management agencies often make one-time payments (known as "flood easements") to property owners in areas that will be allowed to flood periodically to help cover the costs of flooding.
Pelagic Fish Species-Fish that live their whole life in open water, above the bottom. Within the Delta, this category includes delta smelt, longfin smelt, and striped bass.
PL 84-99 Standards-Minimal standards for levee construction in the Delta to qualify for federal assistance in repairs and rehabilitation.
Outflow-Flows of water going away from a particular location.
Salinity-The concentration of salt in water. As a rough guide, seawater is 35 parts per thousand (ppt) (grams per liter) and fresh water is less than 3.0 ppt. Drinking water is less than 1.0 ppt.
Unimpaired Flows-Streamflows unaffected by upstream dams, diversions, or return flows.
Upstream Diversions-Indirect exports from the Delta watersheds (mainly in the Sacramento Valley and on the east side of the San Joaquin Valley) before the water reaches the Delta.
Water Diversions-The withdrawal of water from a water body, some of which might be returned downstream after use.
Water Exports-In general, water used somewhere other than its area of origin.
Direct Delta-exports refers to water from Delta watersheds that is sent to points south and west of the Delta.
Upstream Diversions-are a form of indirect exports.
Water scarcity-Occurs when water deliveries are less than desired. Scarcity is often managed by price, rationing urban water use, fallowing some farmland, or curtailing recreational activities.
Water transfers-The exchange, leasing, or permanent sale of the rights to use a particular amount of water from a particular source. Such transfers occur through a "water market," usually involving local and regional water agencies and often state and federal agencies.
Water Year-California's water year begins on October 1st, the beginning of the rainy season, and ends on September 30th.