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Healthy forests are conducive to the well being of Americans because forests provide our cities and towns with sparkling clean water and pure air. Forests also provide safe refuges for wildlife and some of our most endangered species of plants and animals.

Think of trees and forests as giant filters for cleaning the water that runs through millions of American homes and purifying the air of polluted particles. Forest Service research shows that 80 percent of fresh groundwater in the United States originates from federal forestlands. The role of forests in sequestering carbon from the air is also well documented.

Groundwater is the portion of precipitation (snow and rain) that infiltrates into the soil and bedrock. When rain falls or snow melts, some of it evaporates into the atmosphere, some of it flows across the ground surface directly into lakes, streams and wetlands, some of it is taken up by plants and transpired into the atmosphere, and the rest seeps into the ground to become groundwater (see the diagram of the water or hydrologic cycle below).

The hydrologic cycle describes how water moves from the atmosphere to the land to the ocean and back (see the diagram below). Precipitation that falls on the land surface evaporates, runs off into surface waters or infiltrates. Some of the infiltrated moisture evaporates and transpires, while the rest becomes part of the groundwater as recharge. The groundwater flows in the subsurface until it discharges into streams, lakes, springs, seeps and wetlands, where it becomes surface water. Some surface water evaporates and transpires, some recharges groundwater and the rest flows to the ocean. Eventually, all of the water vapor accumulated in the atmosphere falls to the earth as precipitation, completing the cycle.

Groundwater is divided into two major components: the unsaturated zone above the water table and the saturated zone, below the water table (as shown in the hydrologic cycle diagram, above).

Household and other water supplies are drawn from the saturated zone. However, land plants develop root systems and extract water and nutrients they need for growth from the unsaturated zone. The saturated zone provides the water that keeps perennial streams flowing during periods without precipitation.

A well open in the saturated zone below the water table would have standing water in it because spaces between the soil or rock particles (fractures and pores) are filled with water. However, a well open only in the unsaturated zone above the water table would be dry because its fractures and pores are filled with a mixture of water and air.

Under the proposed groundwater directive, surface water and groundwater would be managed as a single hydraulically interconnected resource unless site-specific data demonstrate otherwise. This assumption is consistent with well-accepted scientific understandings of the hydrologic cycle. Under this assumption, all water in a watershed, whether in a stream, lake, wetland or in the groundwater, is considered part of a single container or reservoir of water. In most places, pumping groundwater from a well would cause a reduction in water flow in nearby streams or in water levels in nearby lakes or wetlands. To protect National Forest System natural resources and other water users, an evaluation needs to be conducted to determine whether the reduction is significant in terms of water quality, quantity and timing.

Approximately 99 percent of rural U.S. residents and approximately 51 percent of urban and suburban U.S. residents get their drinking water from groundwater. Thus, adequate supplies of high-quality groundwater are critical to the nation's quality of life. In addition, most rural and many suburban residents dispose of household wastewater through discharge to groundwater from septic systems. Groundwater quality can be adversely affected through direct discharge of contaminants (e.g., leaky landfills, oil spills, agricultural chemicals and septic systems) and through substantial reductions in groundwater levels that release contaminants from soil and rock.

The Forest Service manages the headwaters and recharge areas of locally and regionally important rivers and aquifers. In most places, springs, streamflow and associated ecosystems are sustained during dry periods by the discharge of groundwater. To manage watersheds on National Forest System land, the Forest Service needs to address all the water resources on those lands as a single hydrologic system.

Dear Natalie,

Thank you for your question about what else goes down drains besides water? Because it’s a liquid, water is a principal ingredient of what is in drains, but it also collects and mixes with other chemicals and objects before it enters into our waterways. For example, runoff water from rain and snow storms can include branches, leaves, rocks, oil, and salt from roads. The larger items can clog drainpipes and cause flooding, both within a house as well as across roads and lowland areas. The smaller items can change the chemistry of the water and make it difficult for natural organisms to live.

Inside your home or school, drains can contain any item that will float on or dissolve in water. That includes human waste and toilet paper from people using the bathroom, detergent from washing clothes and dishes, and any chemical you might use to clean your house that is washed down the drain. Scientists are also finding large quantities of pharmaceuticals in drain water, which then enter into the ecosystem and are absorbed or eaten by fish and other aquatic organisms. That means if you take a certain medication and go to the bathroom, any extra medication that you may have eliminated as waste can end up in a fish! It’s important to understand that anything that goes down the drain can end up in a very different place than was originally intended. And while there are a lot of cool microorganisms in sludge and other waste areas, sometimes they cannot handle the amount of non-water ingredients that go down the drain, which results in water pollution.

For more information about how drinking water is treated, go to http://water.epa.gov/learn/kids/drinkingwater/watertreatmentplant_index.cfm.

(From Dr. Kimberly Winter, Nature Watch, US Forest Service)

I presume that the hydraulic interconnected system refers to the link between groundwater and surface waters. Locally, groundwater information is maintained by USGS (http://water.usgs.gov/ogw/) and state drinking water authorities (environmental protection authorities), while surface water information is typically with EPA (http://cfpub.epa.gov/surf/locate/index.cfm) and Departments of Natural Resources. On a body-by-body basis, water budget and monitoring studies can help identify the interconnections and recognize the two as one whole, but the visual, conceptual, and regulatory differences make it challenging for the federal government and all other levels to consider one water system. Fortunately, living in Virginia produces a simpler water law system that can promote unification of ground and surface waters. 

Stream restoration can help clean water, but it varies based on the starting condition of the water, the restoration tactic, and the relative contribution of the tactic’s target to the sum of impairments to the water body. Lots to consider in this question, but choosing a simple practice such as planting mixed, grassy, or woody buffers (30+feet) in a riparian corridor can go a long way to reducing sediment transportation and take up nutrients, while also stabilizing a streambank. (From Jeremy Peichel, Watershed Forestery, US Forest Service)

Concerning hydrologic flow and associated management decisions, local planners and land managers can study maps and satellite imagery to place best management practices where they intercept the most flow so that it can be treated by stormwater treatment practices or infiltrated into the soil.  Infiltration is beneficial because it slows flow and allows time and space for biogeochemical treatment which can remove pollutants.  The same places that are beneficial from a hydrologic perspective (e.g., wetlands and riparian areas) are also bad places to allow development.  Impervious surfaces prevent infiltration. (From Sally Claggett, US Forest Service Liaison, Chesapeake Bay Program)

 

Mary - Teacher/Naturalist in Virginia

In addition to natural stream channel design, new restoration techniques includes use of biofiltration (using plants that are allowed to grow undisturbed in and around streams) and removal of legacy silty sediments and adding improved substrate. The zone immediately below the stream bed, known as the hyporheic zone, has a strong influence on stream ecology, biogeochemical cycling, and stream water temperatures. Ideally, a restored stream should recover natural hydrologic, hydraulic, geomorphic, physiochemical, and biological functions. (From Sally Claggett, US Forest Service Liaison, Chesapeake Bay Program)

Mary - Teacher/Naturalist in Virginia

Stream restorations are becoming better studied than they were previously.  Many are successful, if properly designed and installed.  The process of stream restoration usually involves heavy machinery working in sensitive (wet) areas.  It is often expensive and can cause some temporary harm to the stream.  For these reasons, it is important to justify the relative cost-benefits of the practice and continue to learn from stream restoration successes and failures.  Guidelines hav been developed by the Chesapeake Bay Program for verifying the functionality of the practice of stream restoration over time. (From Sally Claggett, US Forest Service Liaison, Chesapeake Bay Program)

Impermeable surfaces should be compared to a naturalized surface in the same watershed. Take a 10 ft. x 10 ft. square, where a light rain of 1/4th of an inch falls in an hour. An impermeable surface, for example, allows most water to flow over the surface into its watershed (including wetting the surface, roughly 15 gallons), whether a body of water or a storm sewer. This water takes with it any contaminants such as oil, gas, or vehicle fluids that are sitting on the surface, debris and water-solubles such as salt, soil, and trash, and even heat from the road is carried in the water. Contrast that with a bare soil surface that reduces this flow by allowing infiltration (draining into the ground instead of flowing over the surface) in addition to surface ponding. Though both ponding and infiltration vary by soil type, with dry soil, we can assume that most or all of these 15 gallons could be absorbed. Add vegetation and you can increase the size and intensity of the rain event you retain on that 10ft. square and could accept external flows from impermeable surface nearby, as you do in rain gardens, swales, and other green infrastructure designs. What this means for stream restoration is that impermeable surface transports the trappings of sub/urban life to the restoration project in higher volume and faster time than more permeable naturalized surfaces. In-stream restoration is more challenging to sustain over the long-term if not paired with land-based improvements. Street trees are a good example of a basic improvement, as they can reduce or eliminate runoff in low-intensity rain events simply by catching raindrops and directing water flows down the trunk, preventing water from reaching the pavement below! (From Jeremy Peichel, Watershed Forestery, US Forest Service)

 

Hi Lauren, I'm glad you asked about the Chesapeake Bay-- one of the most important estuaries in the world!   The Chesapeake Bay ecosystem has been relatively stable in the long-term-- with a few notable exceptions.  

One of the first big changes was the gradual disappearance of the eastern oyster that used to be so plentiful that they would form reef islands in the Bay.  The entire volume of the Chesapeake Bay used to be filtered and cleaned by oysters every 3 days.   The Bay was literally full of oysters but too many were harvested and it was clear that by the early 1900's the oyster population was in trouble.  Then, poor water quality and disease caused further problems.  Now, oysters are estimated to be less than 1% of their original abundance.  That's too bad, but oyster sanctuaries and oyster gardens are slowly bringing the oyster back.

The other big change --partially connected to the oyster--has been to the water quality of the Chesapeake.  The water quality rapidly deteriorated from about 1970-2000.  With so many people living and working in the Chesapeake region-- some naturally-occurring chemical elements like nitrogen and phosphorus, and other man-made chemicals like medicines, soaps and fertilizers, became water-borne and can be found at levels that are toxic to aquatic life.  Another problem is sediment that becomes suspended in the water and blocks sunlight from underwater plants.  Sediment can also settle-out and make the bottom of the Bay mushy; covering up the naturally hard, sandy bottom that aquatic animals (and people!) prefer.  

Short-term changes to an ecosystem as large as the Bay can be seen with massive weather events like Hurricane Sandy that creates flooding and lots of pollution flushes off the land and into the water.
 
The water quality has been improving lately thanks to land management policies like forest conservation and restoration, and technological improvements like with sewage treatment facilities.  There is still a lot of things that could be done on farm lands and in our towns and cities to improve water quality.  Policies at the state and local government can be put into place to address these.  State and federal government also set regulations to help control overharvesting of shellfish (like crabs and oysters) and finfish (like menhaden and rockfish).  (From Sally Claggett, USDA Forest Service)

Great question Carly!  Forests are the best land use for water quality, especially in the eastern US where forests naturally cover the land.  Forests soak up the water that flows off the surface and can filter that water and the water in the soil.  

Man-induced impacts to forest and other land cover are often harmful to the quality of the water.  Deforestation is a good example.  Deforestation can mean timber harvesting--which eventually comes back as forest-- or it can mean taking out the forests and permanently converting that land to a different use like development.  As you can probably guess, the permanent conversion of forests has much greater impact to aquatic ecosystems.

Tree-planting is one of many man-induced changes that can benefit water quality.  Tree planting is one of the few water quality practices that has many co-benefits as well (co-benefits include: cleaning the air, taking up greenhouse gases and emitting oxygen, cooling the land and water, providing habitat, and improving the aesthetic environment for people).   (From Sally Claggett,, USDA Forest Service) 

Thank you for this interesting question.  How long a fish can survive in polluted water depends on a lot of things.  It depends on the type of pollution, the concentration of the pollutant (i.e., the volume of pollutant divided by the volume of water), the species of fish, and other environmental conditions, like the temperature of the water. 

Some kinds of pollution such as the release of raw sewage can start a chain of events that cause most of the dissolved oxygen in the water to be used up.  Sadly, when there is not enough dissolved oxygen in the water, all the complex animals, like fish, that need dissolved oxygen will die quite quickly. 

The effects of other kinds of pollution, like the presence of toxic chemicals have different effects depending on the chemical's composition and how much of it there is in the environment.  Scientists have spent lots of time collecting data on how long it takes for different concentrations of a wide variety of chemicals to kill certain species of fish.  These kinds of experiments are known as toxicity tests.  One of the species of fish most commonly used in toxicity tests is the fathead minnow (Pimephales promelas,http://eol.org/pages/211492/details).  On average, fathead minnows live two to three years in the wild.  Contrast this natural 2-3 year lifespan with studies that show that with as little as 30 milligrams of a chemical like benzene per liter of water, half of the fathead minnows in the test will die within two days (48 hours).  That is not very much benzene!  It's about the same as having one teaspoon of sugar in 48 gallons of Kool-Aid.  Believe me, that would be some weak Kool-Aid!  (Benzene used to be commonly used as an industrial solvent in the US, but it is used much less often now because of how toxic it is.)  In this test, the environmental conditions were ideal for the fish, other than the presence of the toxic chemical, that is. 

When fish are stressed because of environmental conditions that are outside of their comfort zone, they are also more likely to die from pollution.  For example, when the water fish live in is too warm, pollution can kill them more easily.  The interacting effects of climate change and other human-caused stressors like pollution mean that many populations of fish are threatened.  To conserve fish and other aquatic life, we all need to find ways to help keep water clean and cool.  (From John Rothlisberger, Aquatic Ecologist, US Forest Service)

Dear Aniya,

Thank you for your question about what else goes down the drain.  Because it’s a liquid, water is a principal ingredient of what is in drains, but it also collects and mixes with other chemicals and objects before it enters into our waterways. For example, runoff water from rain and snow storms can include branches, leaves, rocks, oil, and salt from roads. The larger items can clog drainpipes and cause flooding, both within a house as well as across roads and lowland areas. The smaller items can change the chemistry of the water and make it difficult for natural organisms to live.

Inside your home or school, drains can contain any item that will float on or dissolve in water. That includes human waste and toilet paper from people using the bathroom, detergent from washing clothes and dishes, and any chemical you might use to clean your house that is washed down the drain. Scientists are also finding large quantities of pharmaceuticals in drain water, which then enter into the ecosystem and are absorbed or eaten by fish and other aquatic organisms. That means if you take a certain medication and go to the bathroom, any extra medication that you may have eliminated as waste can end up in a fish! It’s important to understand that anything that goes down the drain can end up in a very different place than was originally intended. And while there are a lot of cool microorganisms in sludge and other waste areas, sometimes they cannot handle the amount of non-water ingredients that go down the drain, which results in water pollution.

For more information about how drinking water is treated, go to http://water.epa.gov/learn/kids/drinkingwater/watertreatmentplant_index.cfm.

(From Dr. Kimberly Winter, Nature Watch, US Forest Service)

Thanks for your question, Claire.  Periods of drought are a natural occurrence, and climate change has the potential to increase the frequency and duration of droughts.  The best situation is that water managers take droughts into long-term planning for water supplies.  A diversity of sources gives options when drought occurs.  Normally the sources for water during drought are tapping fresh water that is already in "storage", surface water reservoirs (created by dams e.g., Hoover Dam/Lake Powell) or pumping of groundwater from wells.

In the past, these sources were sufficient for the water demand of a smaller population and shorter duration of droughts.  Today, with higher populations and longer periods of drought these back-up supplies get stretched to the limits of their capacity.


To answer your question though, there are not many new short-term alternative sources to increase the freshwater supplies that in a water manager's control.  Water conservation is the first option, and is used to stretch the existing supply.
  
Locally, there are a few short-term options.  One that is gaining some popularity is "water harvesting".  This is essentially capturing the rain that does fall on the roofs of home and commercial buildings for instance, and storing it locally for use, offsetting use of the city water system. 

Longer-term options would include technologies that reduce the water demand that is used for agriculture and lawns for instance.  A promising technology is developing alternate sources of water, such as de-salinization plants to make fresh water from ocean waters.

In the Forest Service, our focus is on managing lands in a manner that maintains the natural flow of fresh water from our National Forest lands. (From Gregory S. Olsen, Hydrologist, US Forest Service, Prescott National Forest)

Thanks for your question!  The total number of freshwater fish species worldwide is over 14,000.  Including brackish water species, the estimate grows to over 15,000 species worldwide according to the International Union for Conservation of Nature (IUCN).  There are still many undescribed species and uncertainty around taxanomic classifications that would further increase these estimates.  According to the IUCN, freshwater fishes comprise almost 45% of all fish species worldwide and freshwater mollusks about 25% of all mollusk species worldwide.  Freshwater habitats sustain an estimated 126,000 described species, not just fishes and mollusks, but also reptiles, insects, plants, and mammals.     (From Dan Shively, National Fisheries Program Manager for the US Forest Service)

Great question, Dylan!  A spring is a discrete location where groundwater discharges to the surface.  There are a large number of springs in PA, but unfortunately I am not aware of any comprehensive count.  There is one website that seems to list all the springs identified on USGS topographic quadrangle maps in PA - http://pennsylvania.hometownlocator.com/features/physical,class,spring.cfm.  However, it is generally understood that the mapped springs, particularly in the humid-temperate part of the country (like PA), account for only a small portion of the total number of springs in a given area. (From Christopher Carlson, PhD, Acting Deputy Director, USDA Forest Service) 

Thanks for your question, Dylan!  Springs can be very small and unknown to people who don't regularly hike on the land where they are found, so it's difficult to estimate how many are really found in Pennsylvania.  Springs large enough to have names given to them and be recorded number approximately 205, but I would estimate there could be thousands throughout the state.  (From Troy Thompson, Regional Hydrogeologist, Groundwater Program Manager/ Water Rights & Uses Program Manager, US Forest Service Eastern Regional Office)

Stream microorganisms (fungi, protozoa, bacteria, etc.) attack bits of leaves and other organic detritus and a byproduct is denitrification-the release of nitrogen to the air, where it is inert. This process forms the base of the stream food web. (From Sally Claggett, US Forest Service Chesapeake Bay Program Liaison

Thank you for your question, Jennifer.  I think there has been some relatively recent work that suggests that prior assumptions that water in the mantle was limited may be incorrect.  Apparently there are water-bearing minerals in the mantle that in aggregate could contain as much free water as exists on the surface of the earth. (From Chis Carlson, PhD, Acting Deputy Director, USDA Forest Service) 

Thanks for your great question!  The scientific method is very important for studying fresh water, just as it is for our increasing our understanding of the rest of the natural world. Making observations, asking questions, developing testable hypotheses, designing experiments, collecting and analyzing data, and drawing conclusions based on that data is the way we learn more about how to manage watersheds for clean water and for healthy fish and wildlife habitat. In the United States, there are thousands of fish biologists, aquatic ecologists, hydrologists, soil scientists, limnologists that use the scientific method every day to learn more about watersheds and freshwater ecosystems. (From John Rothlisberger, Fish & Aquatic Biologist, US Forest Service) 

Hi Michael. Sunfish species are oftentimes the most numerous fish in warm-water lakes in Pennsylvania.  

 

When the amount of algae reaches a level where the concentration of oxygen is reduced so much that certain fish die, then the algae is too high. Fish die from lack of oxygen.

 

According to EPA, In one year, the average American residence uses over 100,000 gallons (indoors and outside). 
It takes six and a half years for the average American residence to use the amount of water required to fill an Olympic-sized swimming pool (660,000 gallons). It takes seven and a half years for the average American residence to use the same amount of water that flows over the Niagara Falls in one second (750,000 gallons). American residents use about 100 gallons of water per day.

Well, this is interesting because there isn't just one answer. The Great Lakes are actually melted glaciers from the last Ice Age. Some rivers and lakes have mountain snow melt as their source. Your question was great though, because it typically is rain that recharges the creeks, rivers and lakes.

 

Ocean water is extremely expensive to desalinate, which is the process of extracting the salt water so the remaining water can be used as freshwater. We haven't been able to locate a price for a refinery, but the cost of the water that comes out of the desalination plant is more than $2,000 per acre-foot.

Thank you for your question, Olivia!  California has 10 major water drainages. About 60 billion gallons of precipitation fall into these basins each year, with approximately 51% used for environmental purposes, 39% for agriculture and 11% for urban areas although that varies considerably in wet and dry years. As of fall 2014, about 58% of the state was considered to be in a drought situation (Source Wikipedia). What will it take to end the drought and get “Back to normal” in terms of water for all its uses is very hard to predict. Certainly many natural and man-made storage areas such as reservoirs, wetlands, natural and manmade lakes are extremely impacted by the current drought. It will take years for the soil, streams wetlands and reservoirs to recover. How long? It depends on changes in precipitation, how we manage our supplies and how efficient we can be in conserving what we have.

The current drought has been said to be the driest period in recorded history. However! Many of California’s past droughts in the past 1000 years have been estimated to last 10-20 years based on tree ring growth patterns. The current drought has only been 3 years, which seems pretty small compared to estimates of over 100 years, long ago! We now have a lot more understanding of weather, water storage and conservation of this valuable resource. Through our knowledge and conservation efforts by California’s residents and upstream users we will weather (non pun intended) this current drought. (From Dave Winters, Regional Fishery Program Manager and Aquatic Ecologist, US Forest Service)

Thank you for your question!  Ocean water is extremely expensive to desalinate, which is the process of extracting the salt water so the remaining water can be used as freshwater. We haven't been able to locate a price for a refinery, but the cost of the water that comes out of the desalination plant is more than $2,000 per acre-foot.

It's very difficult to determine depth when water clarity is low, but it can also be hard to tell when the water is crystal clear. Any water body can be dangerously deep because they can look shallow or have strong currents that you cannot see.

Some maps contain bathometric information for lakes, ponds, and rivers. Otherwise, there are tools that scientists use to determine water depth, including lines with weights and sonar. (From Chris Carlson,  Groundwater Leader, US Forest Service)

From Lacey and Alexis in Pennsylvania

In the U.S., it's the White Sturgeon. They live in large rivers along the West Coast of the U.S. and can reach 20 feet in length and nearly 1,800 pounds! Sturgeon are an ancient form of fish that lived during the age of the dinosaurs and there are 27 species around the world. (From Nat Gillespie, Fish Biologist, US Forest Service)

Given that waterborne pathogens are widespread across the planet, it is safest to assume that any surface water may not be safe to drink untreated. When I go backpacking or canoeing in the wilderness, I travel with a water filter and iodine tablets. I then treat or boil all the water I drink to minimize the potential for getting sick. (From Chris Carlson, Groundwater Leader, US Forest Service)

Your best bet is to assume that it's not safe to drink, in case the water has some parasites or viruses in it. ALWAYS boil water taken from a stream or lake before drinking it, and/or use an appropriate filtration device. A common parasite to look out for is Giardia lamblia, which can cause abdominal cramps and upset stomach. (From Mike Eberle, Surface Water Leader, US Forest Service)

Thanks for your question!  This has happened in recent times in dry areas, mostly because of human activity on the landscape. The Colorado River does not normally reach the ocean because it has so many divisions through towns, farms, and orchards that by the time it reaches the Sea of Cortez, what water is left evaporates.(From Sally Claggett, Chesapeake Bay Program, US Forest Service)

From Kamden, Nathan, Christian and Macey

Common freshwater fish found in lakes and ponds in the U.S. include sunfish, bass, catfish and perch (From Nat Gillespie, Fish Biologist, US Forest Service) 

There are hundreds of kinds of fish in freshwater in the U.S., so it depends on what kind of fish you're looking for. Also, many other animals live in our freshwater streams including salamanders and mussels. (From Nat Gillespie, Fish Biologist, US Forest Service) 

Thanks for your question, Sophia!  Salamanders basically eat any insect or living thing they can fit in their mouth, whether that's along the forest floor or at the edge of stream.

Trout hatch from their eggs in the winter or spring each year. The eggs are buried in a shallow layer of gravel, and so when trout first hatch they are call alevins, and they eat their yolk sacks for several weeks.  As they venture out of their hiding places underneath the gravel, they are called fry and begin eating small insect and algae that live in the water.  Trout follow this same pattern in Virginia, Georgia or Maine! (From Nat Gillespie, Fish Biologist, US Forest Service) 

Some fish definitely use rocks on stream and lake beds and banks as habitat.  (From Chris Carlson, Groundwater Leader, US Forest Service)

There are some organisms that live in water that would make humans sick if they ingested them, others that have bites that contain some toxins, and others that can create reactions upon contact with skin. (From Chris Carlson, Groundwater Leader, US Forest Service)

Common freshwater fish found in lakes and ponds in the U.S. include sunfish, bass, catfish and perch. (From Nat Gillespie, Fish Biologist, US Forest Service) 

Forest Service Fisheries Biologists are focusing on restoring populations of native brook trout, so we have a lot of research and monitoring concentrated on that species. 

Trout in the Classroom in Virginia raise either Brook or Brown trout, which are the native species. Rainbow are considered invasive.

Saltwater contains dissolved solids that limit the ability of water molecules to move across the interface at the water surface from the liquid to the vapor state, so that freshwater actually evaporates faster than saltwater. (From Chris Carlson, Groundwater Leader, US Forest Service)

Think of trees and forests as giant filters for cleaning the water that runs through millions of American homes and purifying the air of polluted particles. Forest Service research shows that 80 percent of fresh groundwater in the United States originates from federal forestlands. The role of forests in sequestering carbon from the air is also well documented.

Healthy forests are conducive to the wellbeing of Americans because forests provide our cities and towns with sparkling clean water and pure air. Forests also provide safe refuges for wildlife and some of our most endangered species of plants and animals.

Many communities have local watershed groups that work on local water supply and water quality issues.  You can find information on these groups through your State Environmental Agency, and/or at the US EPA’s “Surf Your Watershed” web site at http://cfpub.epa.gov/surf/locate/index.cfm

Everyone can play an active role in protecting water quality even at home:

-Use lawn and garden fertilizers, chemicals and pesticides according to the label directions.
-Dispose of household cleaners, solvents, paints and other chemicals properly (call your local city officials for more information on proper disposal option in your area).
-Avoid spilling gasoline and oil when working on power equipment such as cars and trucks, lawnmowers, tractors and ATVs.
-If you have a septic system, be sure it is maintained and operating properly, especially in rain and snow runoff seasons when groundwater levels are high.

Use water wisely! it is a limited resource!

(From Greg Olsen, a US Forest Service hydrologist at the Prescott National Forest in Arizona)

It is highly likely that somewhere there is “pure water” in the Martian hydrologic cycle.  For water to be flowing, there must be a recharge point and a discharge point.  How water is recharged to the system is the place where the “freshest” water is likely to be found.  On Earth this would be mostly from precipitation.  On Mars it may be a mechanism such as frost condensing moisture out of the thin atmosphere and then melting and soaking into the Martian soil.  Someday we’ll know more. (From Greg Olsen, a US Forest Service hydrologist at the Prescott National Forest in Arizona)

Mrs. McLain’s Class, South Carolina

This is a difficult thing to do. Since a pollutant is a material out of place ecologically, the only way to stop all water pollution is to recycle all the materials we use so that they are never out of place in the environment. (From Ariel E. Lugo, US Forest Service tropical ecologist and leader of the International Institute of Tropical Forestry in Puerto Rico)

 

Mrs. McLain’s Class, South Carolina

The ocean is so big, that it is difficult to imagine that we could change the oceans in any way. In fact, the ocean controls our climate among other things.  So, the big thing about ocean water pollution is the realization that our activities can actually change the ocean and we don't fully understand the implications that such pollution might have.  Will the oceans simply absorb water pollution? Or will they change and cause unexpected effects on us?  For many questions about the ocean we have no answers and need more research! (From Ariel E. Lugo, US Forest Service tropical ecologist and leader of the International Institute of Tropical Forestry in Puerto Rico)

 

Mrs. McLain’s Class, South Carolina

Yes, pollution does affect animals because pollution changes the environment where animals live.  When the environment changes, organisms always react in some way.  However, the change is not always bad, or it could be bad for some and good for other organisms or even in some cases neutral because different types of pollutants have different effects on different kinds of animals.  We found that some pollution that is bad for people (bacteria in water) is actually good for some fish who depend on the bacteria for their food. (From Ariel E. Lugo, US Forest Service tropical ecologist and leader of the International Institute of Tropical Forestry in Puerto Rico)

The water can be cleaned by natural processes (by plants, animals, soil, etc.) or it can be cleaned by processing the water through a treatment plant.  The treatment plant is quicker but it costs money and energy.  You can clean it in days.  Nature will clean it free but it may take longer depending how much pollution we are adding to the system.  Polluted water is full of germs.  In some really badly polluted waters one can count millions of bacteria in a litter of water.  A lot of germs!! (From Ariel E. Lugo, US Forest Service tropical ecologist and leader of the International Institute of Tropical Forestry in Puerto Rico)

Ocean water can be subject to a treatment that takes the salt out of the water and makes fresh water (called desalination).  This process is very expensive and used only under extreme circumstances.  When the sea is polluted with oil spills, also very expensive treatments are put in place to remove the oil and fragment it so that marine organisms can dissipate the oil.  For other pollutants, the ocean is used as a dumping grounds, and it would be cheaper to treat the water before it gets to the ocean.  Filtering ocean water to remove pollutants would be extremely difficult. (From Ariel E. Lugo, US Forest Service tropical ecologist and leader of the International Institute of Tropical Forestry in Puerto Rico)

 

Watersheds are negatively affected when the vegetation is removed, when soils are exposed to erosion, when dangerous chemicals are spilled inside of them, or when we alter their hydrology through channelization or covering the watershed with impermeable materials such as concrete. (From Ariel E. Lugo, US Forest Service tropical ecologist and leader of the International Institute of Tropical Forestry in Puerto Rico)

 

Amanda from Coal Center, PA

Yes, there are many. Here is what I found in the internet: 

Aquatic and semiaquatic mammals are well adapted to life in the water with physical characteristics such as flippers, webbed feet, paddlelike tails and streamlined bodies. Whales, dolphins, porpoises, manatee and dugong are completely aquatic; seals, sea lions, walrus, hippopotamus, platypus, otters, beavers and nutria are semiaquatic, spending part of their lives on land. (From Ariel E. Lugo, US Forest Service tropical ecologist and leader of the International Institute of Tropical Forestry in Puerto Rico)

 

From Naomi in Coal Center, PA

At a large scale, the best way is to run the water through soil or wetlands. (From Ariel E. Lugo, US Forest Service tropical ecologist and leader of the International Institute of Tropical Forestry in Puerto Rico)

Steven from New Rochelle

There is a lot of water on Earth – about 1,386,000,000 cubic kilometers.  The vast majority of that water (about 97.5%) is salt water.  The remaining 2.5% is freshwater, with almost 70% of that freshwater locked up in ice.  Almost all of the rest of the freshwater is groundwater (about 30%).  Fresh surface water, where most Americans get their drinking water, is only about 0.03 % of the total fresh water, or about 0.0008% of the total water on Earth.  Fresh water is not evenly distributed around the planet.  Some areas have an abundance, such as the Great Lakes, while other areas have very little, such as the Gobi Desert. (From Chris Carlson, National Groundwater Program Leader for the US Forest Service)

 

Steven from New Rochelle

The exploration of Mars completed to date suggests that water existed on Mars in the past.  There is evidence of flowing water on the surface and of minerals that are only known to form in the presence of liquid water.  The current atmosphere on Mars does not provide the conditions for water remaining on the surface for extended periods of time.  What is not entirely clear is whether liquid water exists below the ground surface.  Some recent work suggests that it might.  We will need to continue to watch the news for the results from the ongoing work looking at Mars. (From Chris Carlson, National Groundwater Program Leader for the US Forest Service)

 

Rafael and Steven from New Rochelle

Salt water is a natural product of the water cycle and weathering.  Weathering is the process of breaking down the rocks and minerals that make up the solid part of the Earth.  As those rocks and minerals break down different salts are produced.  Those salts dissolve into the water that comes in contact with those rocks and minerals, such as rain.  As the water flows downhill, more and more salts are accumulated in the water.  Luckily for us and the other species that require fresh water for survival, that water does not usually become too salty for us until it flows into the sea or closed basins like the Great Salt Lake.  In the sea, those salts have concentrated through time as the fresh water evaporates off to restart the water cycle, leaving the salts behind. (From Chris Carlson, National Groundwater Program Leader for the US Forest Service)

From Mrs. Allen's Class in Eldersburg, MD

Humans drink water In order to maintain appropriate amounts of water throughout our bodies.  By weight, humans are made up of about 2/3 water.  Blood is about 90 percent water, muscles and the brain are about 75 percent water, and bones are about 20 percent water. Our bodies use water to process food, move nutrients and oxygen, and remove waste products.  We also use water to maintain our body temperature.  The water we have in our bodies is cycled and released. (From Chris Carlson, National Groundwater Program Leader for the US Forest Service)

From Nick in Coal Center, PA

There are a number of requirements imposed on the drilling, development, production, and closure and reclamation of natural gas wells designed to protect surface water and groundwater from pollution.  If all the work is completed and maintained appropriately, natural gas wells should not contaminate water.  That being said, many of those requirements were developed based on bad experiences in the past.  Because production of natural gas is a complex process with many steps and many different people involved, mistakes can be made and accidents can happen that can result in contamination of water.(From Chris Carlson, National Groundwater Program Leader for the US Forest Service)

Great question!  To my knowledge there are no good estimates of the total amount of groundwater under the United States.  According to the USGS, in 2005 in the US we used about 82.6 billion gallons of groundwater per day.  If you do the math, that means that we use 30 trillion gallons of groundwater each year.  We have yet to completely run out, but we have used groundwater much faster than it is recharged by rainfall in many areas and are running very short in some places, such as the Central Valley of California, Las Vegas, and parts of the Great Plains. (From Chris Carlson, National Groundwater Program Leader for the US Forest Service)

From Kristen in Coal Center, PA

The kinds of animals that live in water near you vary by biogeographic region.  For example, aquatic community assemblages in the Pacific Northwest tend to be less species-rich and typically include trout, salmon, mountain whitefish, suckers, and a few minnow and chub species.  In the Southeastern U.S., however, aquatic community assemblages are much more species-rich and include many more varied species of cyprids, sunfishes, and catfish.   (From Dan Shively, National Fisheries Program Manager for the US Forest Service)

The number of fish that a person catches in a day varies substantially by the type of fishery and target species.  Commercial anglers, who make a living fishing, can catch hundreds of fish each day if the conditions are right and there is an abundance of fish to catch.  Recreational anglers who fish with a rod and reel from the streambank or lakeshore can catch up to their limit each day as set by harvest regulation in each state.  Each state sets angling and harvest regulations that specify how you can fish, what you can fish for, what time of year you can fish, what size fish you’re allowed to keep and how many.   (From Dan Shively, National Fisheries Program Manager for the US Forest Service)

Wetlands serve a critical function in the environment.  Wetlands filter water that runs off overland and removes pollutants such as toxic substances and heavy metals.  Water leaving wetlands is typically cleaner, cooler, and higher quality.  Wetlands also serve to store water like a sponge and allow for a more gradual release into downstream rivers and streams which is very helpful to buffer against flooding and also to improve streamflows during summer drought conditions.  (From Dan Shively, National Fisheries Program Manager for the US Forest Service)

From the Duck Pond in Mississippi

The human demands for freshwater is very high and in many places exceeds the amount of water available in streams and rivers.  Throughout much of the Western United States many streams and rivers are over-appropriated, which means the number of water rights to withdraw water for irrigation, drinking water, industrial uses, and other needs exceeds the total amount of water available.  In those cases, if all the water rights were exercised, the stream or river could dry up which has happened in the past and will likely continue to happen into the future.  As the human population continues to grow and changing climate affects water availability, the demands for water will continue to grow and the availability will likely decrease in certain areas.  This will result in even greater challenges to balance human needs with instream flow needs for fish and wildlife that depend on water in lakes, rivers, and streams.  (From Dan Shively, National Fisheries Program Manager for the US Forest Service)

From Savanna in Coal Center, PA

The different pigments or color in water can be created by living organisms (plants and animals) or from different soils carried into water by runoff from hills, fields and other landforms.  Microscopic plants in water (algae) contain pigments of various colors. When a bloom of algae occurs, the water can turn green or other colors from the pigments in them (greem for example).  I have fished northern Wisconsin lakes that are coffee colored from decomposition of plants and related vegetation.  (From Nick Schmal, retired US Forest Service aquatic habitat specialist)

This is a very interesting question. First, it is important to know what types of health risks can be associated when drinking water if you are stranded.  If you are hiking in a remote or wilderness area, you might be able to drink water from a lake or stream, but you need to understand that you risk the intake of protozoans, bacteria, and/or viruses that can make you very sick. Pesticides, herbicides and other toxins and pollutants associated with agriculture and urban development do not normally impact water sources found deep in wilderness areas.

However a growing threat to backcountry water is the increase in blue-green algae (cyanobacteria) such as Microcystis, which may secrete harmful toxins. Treat any water that shows an algae bloom or harbors significant floating algae. If you plan a trip in a remote area, always carry some treatment method to disinfect any water source you consider contaminated. Be observant at water sources if you're in a remote area. If you see no obvious signs of human or animal activity, then water is  probably clean and may be drinkable without treatment. Be diligent to maintain good personal hygiene when in the wild. Health complications can result from poor sanitation practices, particularly dirty hands. (From Nick Schmal, retired US Forest Service aquatic habitat specialist)

Great question. So what determines the diversity of organsims or biodiversity in an average lake?  Many studies have been conducted on fish, invertebrates and other organisms in lakes, reservoirs, and ponds. But generally, many factors contribute to the number and types of species that occur in lakes. The age of the lake, lake isolation (is it connected to a stream, river or the ocean?), productivity (amount of available nutrients), size, and latitude (warm or cold climate e.g., water temeratures) may all influence, the diversity of organisms. Most organisms will be found in the shallow littoral (shoreline) areas of the lake.  But many species live on the bottom of a lake (benthic species).  In addition, some speices live in open water or profundal zones of a lake. If you want to learn more about lakes across the world, and how to better manage lakes, check out this web site entitled: Integrated Lake Basin Training Materials: http://wldb.ilec.or.jp/ILBMTrainingMaterials/modules.html. (From Nick Schmal, retired US Forest Service aquatic habitat specialist)

Our bodies depend on both water and salt to function. Water is the universal solvent for proteins and is essential for chemical reactions that help us metabolize food, use our muscles, and help to pump our. Our cells also depend on salt, which exists as sodium and chloride ions in fluids, for those same chemical reactions. So, is there a problem if we drink saltwater? Too little or too much salt causes health risks in our bodies. Saltwater is a hypertonic fluid, or one that contains more salt than human blood, and it has a salinity of 35. If any large amount of fluid, is introduced into the human body higher than required salinity, cell damage will occur. In rare cases, drinking an extreme amount of freshwater in a short time can be dangerous too. It can cause the level of salt, or sodium, in your blood to drop too low. That's a condition called hyponatremia. It's very serious, and can be fatal and is called water intoxication. But remember, If you're feeling drained, get a pick-me-up with water. Dehydration makes you feel tired. The right amount of water will help your heart pump your blood more effectively. And water can help your blood transport oxygen and other essential nutrients to your cells. You will always feel better.  (From Nick Schmal, retired US Forest Service aquatic habitat specialist)

Used domestic or household water (wastewater) from activities such as flushing toilets, bathing and washing clothes, is cleaned to meet standards set by state and federal government agencies. Mother Nature has natural cleansing processes of  sunlight, plants, bacteria and filtration by soils in forests and wetlands. However in a heavily populated world, Mother Nature’s capabilities are not enough. As a result, wastewater treatment systems are essential. They typically work by enhancing, speeding up and simulating the filtration, decomposition and  disinfection processes that occur naturally in the environment.

Salt water can get purified using a similar process used for freshwater. Polluted water collection, conveyance, treatment, reuse and disposal services are provided primarily by a variety of public agencies, including cities, counties, and special districts such as sanitary, sanitation and community services districts.  A mixture of pipes, hydraulic structures and pumping facilities collect and convey the wastewater from residences, schools and businesses to treatment facilities that use physical, biological, chemical and advanced processes to reduce or remove organic matter, solids, nutrients, disease-causing organisms and other pollutants before discharging the treated wastewater into rivers, oceans, lakes, and other water bodies or onto land.

In addition, there are some privatized systems, and where treatment plants are not available or feasible, such as in sparsely populated rural areas, individualized on-site sanitation systems like septic tanks and leach lines are used.

If you want to remove salt from sea (salt) water, that process is more involved than just removing pollutants.  Desalination means removing salt from saline (salty) water. Sea water is the basic source of water for our planet. But we cannot use it for drinking or other domestic purposes because it is too salty. Desalination renders sea water usable for human inhabitation. The traditional method is to distill water. In other words, heat the sea water to vaporize it, remove the vapor to a different container and condense the water vapor by cooling it.  Rainfall is an example of the natural distillation process. The next alternative is to freeze the sea water and then thaw the ice thus formed.  Icebergs are examples of natural freeze-thaw process.  Reverse osmosis is a man-made process which can also desalinate sea water. In reverse osmosis,  sea water is forced through a semi-permeable membrane that allows only water molecules to pass through, and which retains all other impurities in water, including the ions of salt. (From Nick Schmal, retired US Forest Service aquatic habitat specialist)

 

Let's begin by defining minerals. Minerals are inorganic substances (such as rocks and similar matter) found in the earth strata, as opposed to organic substances such as plant and animal matter (organsims). Some familiar minerals are what we think of as “good minerals” – things like calcium, magnesium and potassium. There are also “not so good” minerals – at least as far as the human body is concerned – things like lead, arsenic,  mercury, aluminum, etc. So, not all minerals are good for you. There are many types of organisms (species) that can occur in freshwater. The most familiar kind of animals are fish followed by insects (invertebrates) and crustaceans (crayfish) and molluscs (snails, mussels, and clams).  But freshwater also contains many types of aquatic plants that either float in the water or grow from the substrate or bottom of a lake or river. But algea also are found in freshwater. Algae are simple nonflowering plants of a large group that includes the seaweeds and many single-celled forms. (From Nick Schmal, retired US Forest Service aquatic habitat specialist)

 

From Nik in Pennsylvania

Wetlands are amazing places for many reasons.  They store water, control water flow, prevent flooding, act as a filter, improve water quality, and provide habitat for a wide variety of unique plants and animals.  In fact, wetlands are biodiversity hotspots.  This means that wetlands are places where you can find a wider assortment of plants and animals than almost anywhere else.  Thousands of species of insects, birds, fish, amphibians, and mammals use wetland habitat.  Some of my favorite wetland animals are dragonflies, red-winged blackbirds, Eastern newts (a type of salamander), and minks.  You can learn a lot more about wetlands at http://wetlandslive.pwnet.org/. (From John Rothlisberger, Aquatic Ecologist with the US Forest Service)

 

The water in streams and lakes is not salty like the water in the ocean because streams and lakes are fed by water that falls on the surface of the land as precipitation (i.e., rain and snow).  Precipitation is not salty because it comes from clouds that are formed by evaporation.  When water evaporates from a body of water, even a salty body of water (like the ocean), only the water molecules and none of the salt that is dissolved in the liquid water enter the atmosphere to form clouds.  When it rains or snows, this freshwater moves through streams, lakes, and groundwater until it reaches the ocean, along the way it picks up relatively small amounts of salt from the land.  This salt is left behind in the ocean when the water evaporates again, making the ocean salty.  You can learn more about the water cycle at http://water.usgs.gov/edu/watercycle.html. (From John Rothlisberger, Aquatic Ecologist with the US Forest Service)   

Worldwide, one of the most dangerous animals that regularly uses wetland habitat is the hippopotamus.  You can read more about hippos and learn about human-hippo conflicts and conservation efforts at http://www.smithsonianmag.com/science-nature/hippo-haven-107453678/. There aren’t any hippos in the wild in the United States, but you should watch out for them if you have the chance to spend time near riparian wetlands in Africa. (From John Rothlisberger, Aquatic Ecologist with the US Forest Service)

As a group, freshwater mussels known as unionids are some of the most endangered species that live in streams, rivers, and lakes.  More different types of freshwater mussels are native to the southeastern United States than anywhere else in the world.  Many of these mussels, however, are becoming rare because of water pollution, habitat loss, and habitat fragmentation. (From John Rothlisberger, Aquatic Ecologist with the US Forest Service)

In general, marine life lives in ocean water.  Clean ocean water is the best type of water for marine life.  The best water temperature, saltiness, and light levels are different for different marine species.  Some marine species spend part of their life cycle in fresh water or brackish water (i.e., water in estuaries where fresh water and salt water mix).  For example, Pacific salmon, like the Chinook Salmon, spend most of their adult life in the ocean, but then return to freshwater rivers to lay eggs.  Juvenile salmon live in these rivers for a short time and then make their way downstream to the ocean. (From John Rothlisberger, Aquatic Ecologist with the US Forest Service)

From Brian in New Rochelle, NY

For marine life, it is important for ocean water to be clean, even if it is salty.  To keep ocean water clean, we need to avoid releasing toxic chemicals into the environment and not dispose of garbage in waterways.  I think you may be asking how we can remove salt from salt water so that it is safe for humans to drink.  This can be accomplished through a process known as reverse osmosis.  This process separates the salt dissolved in the water from the water molecules.  Reverse osmosis plants are  expensive to build and to maintain, but in places where water is scarce they have been used successfully to supply water for people.  One of the largest reverse osmosis plants in the world is located in Israel. (From John Rothlisberger, Aquatic Ecologist with the US Forest Service)   

Survival experts say that, on average, a human can survive for three days without water.  There are a few cases where humans have survived eight to ten days without water, but these are rare instances.  In contrast, a human can survive for three weeks without food. (From John Rothlisberger, Aquatic Ecologist with the US Forest Service)

Even if you don’t live near mountains, you still live in a watershed, so your watershed is all around you.  Every location in the world is part of a watershed, because water runs downhill, even if the hills aren’t steep.  The definition of a watershed is an area of land that collects water flowing into different streams, rivers, basins, or seas.  You can find out more about the watershed where you live by using the Environmental Protection Agency’s Surf Your Watershed website athttp://cfpub.epa.gov/surf/locate/index.cfm

The water that comes out of your faucet may or may not come from the immediate watershed that you live in, but watersheds are nested so if you expand out far enough, the water that you drink probably does come from your broader watershed.  Your water may come from a well that extracts water from the ground.  Groundwater is also part of the watershed.  Environmental conditions on the surface of a watershed can affect the groundwater there, too. (From John Rothlisberger, Aquatic Ecologist with the US Forest Service)

You could check the NASA web site:  http://science.nasa.gov/about-us/science-strategy/past-strategy-documents/earth-science-enterprise-plans/earth-science-focus-area-roadmaps-2005/carbon-cycle-ecosystems/:   “Environmental change and human activities alter Earth's ecosystems and the biogeochemical cycles that are critical to the habitability of our planet. In addition to providing habitat and natural resources while nurturing crucial biodiversity, ecosystems interact with numerous geochemical and physical systems to maintain the global carbon cycle and its control over changes in atmospheric CO2 and CH4 and thus climate. Over the past two centuries, fossil fuel emissions and other human activities increased atmospheric CO2 by 30% and CH4 by 150% to concentrations unprecedented over the past 400,000 years. Understanding these aspects of the Earth system is fundamental to NASA's mission to protect our home planet.”

The US Geological Survey has a good model of Carbon and Nutrient Cycling: http://pubs.usgs.gov/fs/2009/3078/

Water quality problems and human health issues can be caused by invasive species.There are harmful exotic aquatic species of invertebrates and vertebrates that can cause a lot of environmental problems in waters they infest.  Some of these invasive species are fish, such as Snakehead fish, Round Goby, and Asian Carp, Others are invertebrate species such as Rusty Crawfish, New Zealand Mudsnail, Asian Clam, Chinese trap-door snails, and Spiny Waterflea. (From Michael Ielmini, Certified Wildlife Biologist and National Invasive Species Program Manager for the US Forest Service)

 

Sugar, Grade 6, from California

The best way to waste less water is to simply use less water in what you do! That can mean turning off the faucet while you brush your teeth, taking a shorter shower, or being more thoughtful about how much water you use to water the lawn and garden. The EPA has a great website to help you waste less water: https://www3.epa.gov/watersense/kids/simpleways.html

Desiree in Seventh Grade in Washington
Groundwater is an important part of the global hydrologic cycle.  About 2/3 of the non-frozen freshwater on Earth is stored in groundwater.  Groundwater is “recharged” by precipitation that infiltrates into the soil and bedrock.  Groundwater “discharges” to surface waters such as springs and wetlands, through transpiration by plants, and through wells used to provide water for crops, drinking water, and other human uses.  Soil and rock materials that hold enough water that it can be readily withdrawn by wells are called “aquifers.”  When humans tap aquifers for water, the groundwater system adjusts to that new discharge through a combination of increased recharge, reduced discharge to other wells and surface waters, and a reduction of total water in the aquifer.  Because individual aquifers hold a finite amount of water, we can withdraw that water faster than it can recharge, leading to serious water supply and ecological problems.   These problems can be compounded when we have also lessened the water available for recharge by developing roads, houses, and other impervious surfaces.

Using water-saving techniques diverts less water from our rivers, bays, and estuaries, which helps keep the environment healthy and can save money, too!  Less demand on wastewater treatment, which converts used water into drinkable water, helps to reduce the amount of energy and chemicals used to treat, pump, and heat water.  These are all energy demands and can cause pollution of their own, so reducing those demands by using less water overall is great for the environment.

Impermeable surfaces should be compared to a naturalized surface in the same watershed. Take a 10 ft. x 10 ft. square, where a light rain of 1/4th of an inch falls in an hour. An impermeable surface, for example, allows most water to flow over the surface into its watershed (including wetting the surface, roughly 15 gallons), whether a body of water or a storm sewer. This water takes with it any contaminants such as oil, gas, or vehicle fluids that are sitting on the surface, debris and water-solubles such as salt, soil, and trash, and even heat from the road is carried in the water. Contrast that with a bare soil surface that reduces this flow by allowing infiltration (draining into the ground instead of flowing over the surface) in addition to surface ponding. Though both ponding and infiltration vary by soil type, with dry soil, we can assume that most or all of these 15 gallons could be absorbed. Add vegetation and you can increase the size and intensity of the rain event you retain on that 10ft. square and could accept external flows from impermeable surface nearby, as you do in rain gardens, swales, and other green infrastructure designs. What this means for stream restoration is that impermeable surface transports the trappings of sub/urban life to the restoration project in higher volume and faster time than more permeable naturalized surfaces. In-stream restoration is more challenging to sustain over the long-term if not paired with land-based improvements. Street trees are a good example of a basic improvement, as they can reduce or eliminate runoff in low-intensity rain events simply by catching raindrops and directing water flows down the trunk, preventing water from reaching the pavement below! (From Jeremy Peichel, Watershed Forestery, US Forest Service)

Impermeable or impervious surfaces can impact restoration efforts by increasing the velocity of runoff in the stream system.  This increased velocity causes erosion and the sedimentation can overwhelm the restored area of the stream. (From Sally Claggett, US Forest Service Liaison, Chesapeake Bay Program)

Thanks for your question, Mariah. The common species name sea trout refers to sea-going brown trout (Salmo trutta).  This species is native in Europe and has been introduced in the United States and elsewhere.  As the name implies, sea trout journey to the ocean after rearing in freshwater for one to three years.  Once in the ocean, sea trout have access to more abundant food resources and can grow to a much larger size.  As adult fish, they migrate back to their natal streams to spawn and repeat their life cycle and hence are referred to as "anadromous" fish.  So, can sea trout live in ponds?  Well, technically they could only live in ponds that provide suitable habitat conditions for the first phase of their freshwater life cycle.  Within one to three years, sea trout would have to leave the pond and migrate to the ocean in order to complete their anadromous life cycle.  (From Dan Shively, National Fisheries Program Manager, US Forest Service)    

Thanks for your question, Mya.  Sea trout, like other trout species, require cool clean water in the rivers and streams where they spend the first few years of life as juveniles and upon returning from the ocean as spawning adults. Pollution and other human disturbances can lower water quality affecting species survival and reproduction. To determine the quality and condition of water and other habitat variables in rivers or streams where sea trout live during the early and late phases of their anadromous life cycle, specific testing and sampling would be required. (From Dan Shively, National Fisheries Program Manager, US Forest Service)    

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