Turbidity is a measure of the level of particles such as sediment, plankton, or organic by-products, in a body of water. It is a measure of the degree to which the water loses its transparency due to the presence of suspended particulates. Turbidity is an optical characteristic of water and is a measurement of the amount of light that is scattered by the particles in the water. High turbidity makes water appear cloudy or muddy. Turbidity is considered as a good measure of the quality of water.
Turbidity is an important factor in water quality, and it can be affected by natural factors such as runoff caused by precipitation and/or severe weather, disruption of bottom sediments due to water turbulence from windstorms or rain events, and small floating organisms suspended in the water column. Human activities that disturb land, such as construction, mining, and agriculture, can also lead to high sediment levels entering water bodies during rainstorms due to stormwater runoff.
High turbidity levels can reduce the amount of light reaching lower depths in water bodies such as lakes, rivers, and reservoirs, which can inhibit the growth of submerged aquatic plants and consequently affect species that are dependent on them, such as fish and shellfish. High turbidity levels can also affect the ability of fish gills to absorb dissolved oxygen.
Turbidity can be measured using a turbidimeter, which estimates the level of total suspended solids (TSS) concentration in the water. Water samples should be taken at regular intervals across a water body and at various depths to account for variations in turbidity. Basic field data collected by a water quality monitoring program should include turbidity along with other parameters that may influence turbidity, such as temperature, streamflow, dissolved oxygen, specific conductance, and pH.
