Surface water

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Image of the entire surface water flow of the Alapaha River near Jennings, Florida going into a sinkhole leading to the Floridan Aquifer groundwater. AlapahaRiver2002.jpg
Image of the entire surface water flow of the Alapaha River near Jennings, Florida going into a sinkhole leading to the Floridan Aquifer groundwater.
Grey headed flying fox - skimming water - AndrewMercer - DSC00530.jpg
An example of surface water is Lake Kinney. Lake Kinney mit Mount Whitehorn.jpg
An example of surface water is Lake Kinney.

Surface water is water located on top of the Earth's surface such as rivers, creeks, and wetlands. This may also be referred to as blue water. The vast majority is produced by precipitation and water runoff from nearby areas. As the climate warms in the spring, snowmelt runs off towards nearby streams and rivers contributing towards a large portion of our drinking water. Levels of surface water lessen as a result of evaporation as well as water moving into the ground becoming ground-water. Alongside being used for drinking water, surface water is also used for irrigation, wastewater treatment, livestock, industrial uses, hydropower, and recreation. r [1] It is recorded by the Environmental Protection Agency (EPA), that approximately 68 percent of water provided to communities comes from surface water. [2] For USGS water-use reports, surface water is considered freshwater when it contains less than 1,000 milligrams per liter (m/L) of dissolved solids. [3]


There are three major types of surface water. Permanent (perennial) surface waters are present year round. This includes rivers, swamps, and lakes. Semi-permanent (ephemeral) surface water refers to bodies of water that are only present at certain times of the year including areas such as creeks, lagoons, and waterholes. Man made surface water is water that can be continued by infrastructure that humans have assembled. This would be lakes, dams, and artificial swamps. [4] The surface water held by dams can be used for renewable energy in the form of hydropower. Hydropower is the forcing of surface water sourced from rivers and streams to produce energy. [5]

Measuring Surface Water

A stream gauge used to measure surface water. DNRC Stream Gage below Nevada Reservoir on Nevada Creek.jpg
A stream gauge used to measure surface water.

Surface water can be measured as annual runoff. This includes the amount of rain and snowmelt drainage left after the uptake of nature, evaporation from land, and transpiration from vegetation. In areas such as California, the California Water Science Center records the flow of surface water and annual runoff by utilizing a network of approximately 500 stream gages collecting real time data from all across the state. This then contributes to the 8,000 stream gage stations that are overseen by the USGS national stream gage record. This in turn has provided to date records and documents of water data over the years. Management teams that oversee the distribution of water are then able to make decisions of adequate water supply to sectors. These include municipal, industrial, agricultural, renewable energy (hydropower), and storage in reservoirs. [6]

Climate Change Impacts

Due to climate change, sea ice and glaciers are melting rising contributing to the rise in sea levels. As a result, salt water from the ocean is beginning to infiltrate our freshwater aquifers contaminating water used for urban and agricultural services. It is also affecting surrounding ecosystems as it places stress on the wildlife inhabiting those areas. It was recorded by the NOAA in the years 2012 to 2016, ice sheets in Greenland and the Antarctic reduced by 247 billion tons per year. [7] This number will continue to increase as global warming persists.

Global warming has a direct connection with the hydrologic cycle. It has increased evaporation yet decreased precipitation, runoff, groundwater, and soil moisture. This has altered our surface water levels. Climate change also enhances the existing challenges we face in water quality. The quality of our surface water is based off the chemical inputs from the surrounding elements such as the air and the nearby landscape. When these elements are polluted due to human activity, it alters the chemistry of the water. [8] If no progress is made in regards to this pollution of our drinking water will we have to develop more technology to purify it increasing expenses.

Conjunctive use of ground and surface water

Surface and groundwater are two separate entities, so they must be regarded as such. However, there is an ever-increasing need for management of the two as they are part of an interrelated system that is paramount when the demand for water exceeds the available supply (Fetter 464). Depletion of surface and ground water sources for public consumption (including industrial, commercial, and residential) is caused by over-pumping. Aquifers near river systems that are over-pumped have been known to deplete surface water sources as well. Research supporting this has been found in numerous water budgets for a multitude of cities.

Response times for an aquifer are long (Young & Bredehoeft 1972). However, a total ban on ground water usage during water recessions would allow surface water to retain better levels required for sustainable aquatic life. By reducing ground water pumping, the surface water supplies will be able to maintain their levels, as they recharge from direct precipitation, surface runoff, etc.

See also

Related Research Articles

Hydrology The science of the movement, distribution, and quality of water on Earth and other planets

Hydrology is the scientific study of the movement, distribution and management of water on Earth and other planets, including the water cycle, water resources and environmental watershed sustainability. A practitioner of hydrology is called a hydrologist. Hydrologists are scientists studying earth or environmental science, civil or environmental engineering and physical geography. Using various analytical methods and scientific techniques, they collect and analyze data to help solve water related problems such as environmental preservation, natural disasters, and water management.

Aquifer Underground layer of water-bearing permeable rock

An aquifer is an underground layer of water-bearing permeable rock, rock fractures or unconsolidated materials. Groundwater can be extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology. Related terms include aquitard, which is a bed of low permeability along an aquifer, and aquiclude, which is a solid, impermeable area underlying or overlying an aquifer. If the impermeable area overlies the aquifer, pressure could cause it to become a confined aquifer.

Ogallala Aquifer Shallow Aquifer

The Ogallala Aquifer is a shallow water table aquifer surrounded by sand, silt, clay, and gravel located beneath the Great Plains in the United States. One of the world's largest aquifers, it underlies an area of approximately 174,000 sq mi (450,000 km2) in portions of eight states. It was named in 1898 by geologist N. H. Darton from its type locality near the town of Ogallala, Nebraska. The aquifer is part of the High Plains Aquifer System, and rests on the Ogallala Formation, which is the principal geologic unit underlying 80% of the High Plains.

Hydrosphere Combined mass of water found on, under, and above the surface of a planetary body

The hydrosphere is the combined mass of water found on, under, and above the surface of a planet, minor planet or natural satellite. Although Earth's hydrosphere has been around for about 4 billion years, it continues to change in shape. This is caused by seafloor spreading and continental drift, which rearranges the land and ocean.

Water cycle The continuous movement of water on, above and below the surface of the Earth

The water cycle, also known as the hydrologic cycle or the hydrological cycle, describes the continuous movement of water on, above and below the surface of the Earth. The mass of water on Earth remains fairly constant over time but the partitioning of the water into the major reservoirs of ice, fresh water, saline water and atmospheric water is variable depending on a wide range of climatic variables. The water moves from one reservoir to another, such as from river to ocean, or from the ocean to the atmosphere, by the physical processes of evaporation, condensation, precipitation, infiltration, surface runoff, and subsurface flow. In doing so, the water goes through different forms: liquid, solid (ice) and vapor.

Groundwater Water located beneath the ground surface

Groundwater is the water present beneath Earth's surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called the water table. Groundwater is recharged from the surface; it may discharge from the surface naturally at springs and seeps, and can form oases or wetlands. Groundwater is also often withdrawn for agricultural, municipal, and industrial use by constructing and operating extraction wells. The study of the distribution and movement of groundwater is hydrogeology, also called groundwater hydrology.

Environmental degradation deterioration of the environment through depletion of resources such as air, water and soil; the destruction of ecosystems; habitat destruction; the extinction of wildlife; and pollution

Environmental degradation is the deterioration of the environment through depletion of resources such as air, water and soil; the destruction of ecosystems; habitat destruction; the extinction of wildlife; and pollution. It is defined as any change or disturbance to the environment perceived to be deleterious or undesirable. As indicated by the I=PAT equation, environmental impact (I) or degradation is caused by the combination of an already very large and increasing human population (P), continually increasing economic growth or per capita affluence (A), and the application of resource-depleting and polluting technology (T).

In water-related science and engineering, there are two similar but distinct definitions in use for the word drawdown:

Edwards Aquifer

The Edwards Aquifer is one of the most prolific artesian aquifers in the world. Located on the eastern edge of the Edwards Plateau in the U.S. state of Texas, it is the source of drinking water for two million people, and is the primary water supply for agriculture and industry in the aquifer's region. In addition, the Edwards Aquifer feeds the Comal and San Marcos springs, provides springflow for recreational and downstream uses in the Nueces, San Antonio, Guadalupe, and San Marcos river basins, and is home to several unique and endangered species.

The United States Environmental Protection Agency (EPA) Storm Water Management Model is a dynamic rainfall–runoff–subsurface runoff simulation model used for single-event to long-term (continuous) simulation of the surface/subsurface hydrology quantity and quality from primarily urban/suburban areas. It can simulate the Rainfall- runoff, runoff, evaporation, infiltration and groundwater connection for roots, streets, grassed areas, rain gardens and ditches and pipes, for example. The hydrology component of SWMM operates on a collection of subcatchment areas divided into impervious and pervious areas with and without depression storage to predict runoff and pollutant loads from precipitation, evaporation and infiltration losses from each of the subcatchment. Besides, low impact development (LID) and best management practice areas on the subcatchment can be modeled to reduce the impervious and pervious runoff. The routing or hydraulics section of SWMM transports this water and possible associated water quality constituents through a system of closed pipes, open channels, storage/treatment devices, ponds, storages, pumps, orifices, weirs, outlets, outfalls and other regulators. SWMM tracks the quantity and quality of the flow generated within each subcatchment, and the flow rate, flow depth, and quality of water in each pipe and channel during a simulation period composed of multiple fixed or variable time steps. The water quality constituents such as water quality constituents can be simulated from buildup on the subcatchments through washoff to a hydraulic network with optional first order decay and linked pollutant removal, best management practice and low-impact development removal and treatment can be simulated at selected storage nodes. SWMM is one of the hydrology transport models which the EPA and other agencies have applied widely throughout North America and through consultants and universities throughout the world. The latest update notes and new features can be found on the EPA website in the download section. Recently added in November 2015 were the EPA SWMM 5.1 Hydrology Manual and in 2016 the EPA SWMM 5.1 Hydraulic Manual and EPA SWMM 5.1 Water Quality Volume (III) + Errata

Water balance

In hydrology, a water balance equation can be used to describe the flow of water in and out of a system. A system can be one of several hydrological domains, such as a column of soil or a drainage basin. Water balance can also refer to the ways in which an organism maintains water in dry or hot conditions. It is often discussed in reference to plants or arthropods, which have a variety of water retention mechanisms, including a lipid waxy coating that has limited permeability.

Streamflow, or channel runoff, is the flow of water in streams, rivers, and other channels, and is a major element of the water cycle. It is one component of the runoff of water from the land to waterbodies, the other component being surface runoff. Water flowing in channels comes from surface runoff from adjacent hillslopes, from groundwater flow out of the ground, and from water discharged from pipes. The discharge of water flowing in a channel is measured using stream gauges or can be estimated by the Manning equation. The record of flow over time is called a hydrograph. Flooding occurs when the volume of water exceeds the capacity of the channel.

Groundwater recharge Groundwater that recharges an aquifer

Groundwater recharge or deep drainage or deep percolation is a hydrologic process, where water moves downward from surface water to groundwater. Recharge is the primary method through which water enters an aquifer. This process usually occurs in the vadose zone below plant roots and, is often expressed as a flux to the water table surface. Groundwater recharge also encompasses water moving away from the water table farther into the saturated zone. Recharge occurs both naturally and through anthropogenic processes, where rainwater and or reclaimed water is routed to the subsurface.

Overdrafting is the process of extracting groundwater beyond the equilibrium yield of the aquifer.

Subsurface flow, in hydrology, is the flow of water beneath earth's surface as part of the water cycle.

Geographic information systems (GISs) have become a useful and important tool in the field of hydrology to study and manage Earth's water resources. Climate change and greater demands on water resources require a more knowledgeable disposition of arguably one of our most vital resources. Because water in its occurrence varies spatially and temporally throughout the hydrologic cycle, its study using GIS is especially practical. Whereas previous GIS systems were mostly static in their geospatial representation of hydrologic features, GIS platforms are becoming increasingly dynamic, narrowing the gap between historical data and current hydrologic reality.

Water resources Sources of water that are potentially useful

Water resources are natural resources of water that are potentially useful. Uses of water include agricultural, industrial, household, recreational and environmental activities. All living things require water to grow and reproduce.

Water in California Water supply and distribution in the U.S. state of California

California's interconnected water system serves over 30 million people and irrigates over 5,680,000 acres (2,300,000 ha) of farmland. As the world's largest, most productive, and most controversial water system, it manages over 40 million acre feet (49 km3) of water per year.

Water storage every type of water storage, drinkable or not

Water storage is a broad term referring to storage of both potable water for consumption, and non potable water for use in agriculture. In both developing countries and some developed countries found in tropical climates, there is a need to store potable drinking water during the dry season. In agriculture water storage, water is stored for later use in natural water sources, such as groundwater aquifers, soil water, natural wetlands, and small artificial ponds, tanks and reservoirs behind major dams. Storing water invites a host of potential issues regardless of that waters intended purpose, including contamination through organic and inorganic means.

Droughts in California

Throughout history, California has experienced many droughts, such as 1841, 1864, 1924, 1928–1935, 1947–1950, 1959–1960, 1976–1977, 1986–1992, 2006–2010, and 2011–2019. As the most populous state in the United States and a major agricultural producer, drought in California can have a severe economic as well as environmental impact. Drought may be due solely to, or found in combination with, weather conditions; economic or political actions; or population and farming.


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  2. Centers of Disease Control and Prevention (2018-10-10). "Water Sources". Retrieved 2020-04-06.
  3. U.S Department of the Interior. "Surface-Water Use". Retrieved 2020-04-06.
  4. Department of Environment and Natural Resources. "What is Surface Water?" (PDF). Retrieved 2020-04-06.
  5. U.S Energy Information Administration (2020-04-30). "Hydropower Explained".
  6. U.S Department of the Interior. "Surface Water & Drought". Retrieved 2020-04-21.
  7. Rebecca, Lindsey. "Climate Change: Global Sea Level". Retrieved 2020-04-21.
  8. Ganpat, Wayne (January 2017). "Environmental Sustainability and Climate Change Adaptation Strategies". IGI Global. 12: 323–326.