Have you ever looked at a big river like the Mississippi or the Colorado and admired the beauty of the flowing water, the little eddies around sand banks, the floating logs and leafs, the sight of a fish jumping, the reeds along the banks, and wading birds foraging for frogs and other goodies in the shallow water? There is a certain calmness in looking at a river and all the water making its way to sea. Maybe that is why there are so many songs about rivers. My favorite is “Old Man River” from the musical Showboat. And maybe it is why artists so frequently paint rivers. I think my favorites are all those wonderful paintings of the Thames that Whistler did or maybe it is that beautiful painting by Van Gogh of the Rhone River at night. If you’ve thought these things, you are probably an artistic soul.

Have you ever looked at a big river and wondered where does all that water come from, why are there so many sand banks, how did all those logs make their way into the river and what in the world is going to happen to all those leafs, what kind of fish is that in the river and how did it get there, what kind of reeds are those, and what in the world is the bird eating that is wading around in the reeds? If you have wondered these things, you are probably a scientist and you would love reading the Environmental Protection Agency’s  (EPA) January 2015 report entitled: “Connectivity of Streams and Wetlands to Downstream Waters: A Review and Synthesis of the Scientific Evidence.”

The report synthesizes the work of thousands of scientific papers found in the peer reviewed journals where scientific research is published. The report provides a scientific basis for the definition of the “waters of the United States.”  The definition was issued as the Clean Water Rule in the summer of 2015. EPA and the Army Corps of Engineers have long been regulating upstream and adjacent waters to rivers as “waters of the United States.” This led to a number of court cases over the years which eventually wound up in the Supreme Court. The Supreme Court told EPA that they needed to find the physical, chemical, and biological connection upstream and adjacent waters had to downstream waters and define the connection clearly so that the Court didn’t have to be continually harassed by plaintiffs seeking relief from violations they’d received from the federal agencies. Well that’s not exactly what they said but it is the boiled down version.

Today’s post reviews the part of the report covering the connection of streams to rivers. Yes I know that sounds silly. We learned in elementary school that streams are connected to rivers or other water bodies like lakes (even in the desert, streams connect to playa lakes). Look at a map. All the little blue lines indicating water are connected to other larger blue lines. We know them from geography class as tributaries. Who hasn’t walked along a stream and found another little stream coming into it? Who hasn’t jumped the little incoming stream and walked further along the stream bank to find yet another little stream coming into the bigger stream? And if you turned up one of the little incoming stream, you might find the same thing – more tiny incoming streams- all forming a network of tributaries coming into a larger stream which eventually flows into a river.

The uppermost reaches of tributaries are called headwaters. You might call them the origin point of a river’s network of streams. Headwaters have been the source of many an adventurous real life epic. Take for example the great age of explorers back in the 19^th century and all those guys like John Speake, Samuel Baker and his wife Florence, and Richard Burton who risked malaria, nasty critters, and a lot of discomfort looking for the headwaters of the Nile River. But in the 21^st century we tend to like more facts and figures drawn from satellite imagery versus slogging around in the bush. We also like collecting data. So many rivers and streams have permanent hydrographs installed which collect flow data. EPA’s report shows in many parts of the country, headwater streams make up over 50 % of the total stream length in a river’s network of streams. Headwater streams are also called 1^st order streams. First order streams run into second order streams which then run into 3^rd order streams and so forth. Anyway these headwater streams are providing a lot of the water going into rivers. EPA cites one study done in the northeastern part of the United States which shows all the headwater streams in the river systems there are contributing 60 % of the flow to the downstream network of streams and rivers.

The water from those headwater streams comes not just from precipitation but also from groundwater. You may have heard someone say a creek is spring fed. That means groundwater is entering the stream. Groundwater can also feed a river directly. Probably the most striking example I have ever seen of groundwater entering a river is on the Snake River in Idaho where there are rivulets of water cascading from the high basalt banks into the river. Groundwater often provides what hydrologists call baseflow in a stream during dry periods.

So physically streams are connected to rivers by water flow. Even headwater streams that are dry most of the year are providing downstream flows. If you are an easterner, you may not realize in the western part of the United States that people need to be aware of storms going on upstream. Many a person has drowned on a sunny day in a slot canyon when a storm upstream produced a wall of water that swept down an ephemeral stream and filled up a slot canyon where hikers had no escape route.

All sorts of things can affect the physical flow of water in a stream. EPA’s report outlines many of the types of physical flow of water through a river network and how flow in headwater streams impacts the flow downstream through physical changes in the streambed, stream banks and the channel itself. Stream networks are messy natural systems. They are not smooth conduit like pipelines providing a nice unimpeded flow. Large amounts of sediment are being carried by headwaters downstream. Sediment can come from bank erosion and also from natural runoff. Strong storms and floods can move boulders and cobbles downstream. Trees fall into headwaters and are also carried downstream. I spend a lot of time looking at streams. Many of their flows are turbulent because of the amount of sandbars, the huge piles of boulders and cobbles, and the enormous log jams of trees. So obviously the flow of water downstream is being affected by what is being washed out of the headwaters.

EPA also cites temperature as another physical connection linking streams and rivers. This may surprise you, but not if you live on the water. Riparian trees are often protected all along a river network. Ask my ex-neighbor who got a big fine for cutting down trees along the creek bank so he could have a better view of the water. Trees and other vegetation provide shade and lower the water temperature. Solar heat, size of the tributary and entry of groundwater into surface water all control temperature. Temperature has all sorts of effects on downstream waters including eutrophication (low oxygen) which result in fish kills. EPA refers to a number of scientific studies which show upstream waters can impact downstream temperatures over long distances.

EPA has made a clear case for streams having a significant physical “nexus” to rivers. Now let’s look at their evidence for a chemical connection between streams and rivers. The strongest connection as you might well guess is that of nutrients. If you live anywhere near a river you are sensitive to how nutrients impact water. EPA primarily looked at nitrogen and phosphorus. I’m old enough to remember when they took phosphorous out of laundry detergent. Now they’ve taken it out of lawn fertilizer where I live. It’s that old eutrophication problem. The reason phosphorus is in lawn fertilizer is because it promotes plant growth. Put it in the water and it does the same thing. Algae just love it and you get algal blooms which deplete the water of oxygen, which fish need to live. Phosphorous runoff is natural of course, but these days a lot of it comes from agricultural practices. Nitrogen is also a natural occurring nutrient but agricultural development can be a large contributor in stream systems as well.

There have probably been more scientific studies looking at nutrients in river networks than any other kind of study and these studies have clearly documented nutrient connection between headwaters and downstream waters. EPA’s report cites a study which says 1^st order streams contribute 65 % of nitrogen to second order streams and approximately 40 % of the nitrogen in 4^th order and higher streams. EPA also cites studies on processes in headwater streams where nitrogen is sequestered thereby improving water quality downstream. EPA further cites studies where both dissolved nitrogen and phosphorous entering headwaters are taken up by algae and microbes which can be consumed by larger organisms, transported downstream as particulates, and returned to the water via death and decomposition. There are all sorts of complex interactions going on with nutrients in headwater streams that impact downstream water in rivers. EPA has made another clear cut case of connection within river networks.

For me a more interesting chemical connection point is the giant amount of organic detritus entering headwaters and being transported downstream. Not something I’ve thought about much, but all that dissolved and particulate organic matter entering the headwaters from leafs, eroded soil, wetlands and so forth is providing energy for the whole biologic community up stream and down. Downstream organisms such as microbes and algae are feasting on the organic carbon, larger organisms like invertebrates are feasting on the microbes and algae, and fish are feasting on the invertebrates. EPA estimates 31 % of total carbon in downstream waters comes from headwater streams.

This leads right into EPA’s assessment of the biological connection between headwaters and downstream rivers. Again the biological connections between the two are well documented in the scientific literature. All those invertebrates eating and breeding up there in the headwaters are a great source of floating food for downstream fish. I never knew all the functions that these little invertebrates performed nor that so many people spend their time studying what they are up to, but EPA cites a large number of studies that show how invertebrates are breaking down organic particulates into finer and more mobile dissolved forms, how they are promoting algal and microbial productivity, and temporarily storing and transferring sediments, nutrients and even contaminants by their actions. And the fish? Well of course we know that salmon, eels and so forth migrate from the ocean up whole river systems to spawn in headwaters. But did you know other fish spawn in one place then make a runner for it. EPA cites a study of cutthroat trout that spawn upstream than migrate up to 80 kilometers downstream after spawning. There’s even another study of a fish whose eggs float downstream up to 144 kilometers before hatching.  Fascinating. Anyway it is pretty clear fish don’t just stay in one place; they travel up and down river networks for breeding, spawning, feeding and other activities of the daily grind.

I think we can clearly put a mission accomplished banner up for EPA on proving through existing research that headwater streams are connected to downstream waters physically, chemically and biologically.

Today’s post is the second post in a series reviewing EPA’s report “Connectivity of Streams and Wetlands to Downstream Water.”  In my next post I’ll discuss EPA’s findings on connectivity of riparian and floodplain wetlands to downstream

Connectivity. What a great word. I always think of the butterfly effect when I think of connectivity. Someone told me once that it is actually a real effect. It is a part of chaos theory which describes how a small change in one condition can effect a much larger change in a later condition. The butterfly is a metaphor I suppose. The idea being that the flapping of a butterfly’s wings somewhere in South America can change the course of a hurricane in the Atlantic. When I think of connectivity, I also think of six degrees of separation. You know that one: the idea that everyone is connected to everyone else in the world through six other people.

The Environmental Protection Agency (EPA) uses the word “connectivity” as part of the title of their report issued in January 2015, which provides the science supporting the Clean Water Rule.  The report is entitled: “Connectivity of Streams and Wetlands to Downstream Waters: A Review and Synthesis of the Scientific Evidence.” The purpose of the report is to use currently available science in determining the connection of upstream and adjacent waters such as tributaries and wetlands to downstream waters. If you have been reading this blog for awhile you know the EPA issued the Clean Water Rule in the summer of 2015 in order to clarify the definition of the “waters of the United States.” They did so because of several Supreme Court cases where the Court’s written opinion essentially told EPA to determine which upstream and adjacent waters have a “significant nexus” to the chemical, physical or biological integrity of downstream waters of the United States before regulating those upstream and adjacent waters under the Clean Water Act. “Significant nexus” is the court’s word and I guess it is fancy lawyer talk for connection. At least that’s how EPA decided to interpret the word.

EPA is a regulatory agency with a lot of scientists and a lot of lawyers. The scientists and lawyers got together and they decided that “significant nexus” means connection. So they came up with some basic science questions that needed to be answered: What are the physical, chemical, and biological connections to and effects on downstream waters of 1) upstream ephemeral, intermittent and perennial streams, 2) adjacent riparian or floodplain wetlands and open waters, and 3) non-flood plain wetland and open waters.

Ephemeral, intermittent and perennial streams are tributaries to downstream waters. Perennial streams flow most of the year and there is usually a good connection between local or regional aquifers to the stream which keeps them flowing. Intermittent streams are dry part of the year but may have variable flow along their length depending on connection to groundwater.  Ephemeral streams are dry most of the year and flow is dependent on short lived rainfall events or melting snow.  Adjacent riparian or floodplain wetlands are the wetlands we see along the banks and in the shallow water areas of rivers, lakes and streams and in the floodplains of those water bodies. Think of the mighty Mississippi and all those floodplain areas with swamps. Those occur not only at the large scale of a river but at the small scale of a stream. Non-flood plain wetlands are the more diffuse and often widespread type of wetlands. The ones I’m more familiar with are the prairie potholes that exist in the north central part of the country in places like North Dakota, Minnesota and Montana. This area of the country was heavily glaciated during the Ice Age. The big land glaciers covering these states pretty much ground down and flattened everything in their path. When the glaciers receded they left a gouged up terrain of small depressions that fill with water and have all sorts of little microecologies. In many areas the prairie potholes connect with the water table in the glacial alluvium also left behind by the glaciers.

The reason the Supreme Court and the EPA are interested in those physical, chemical and biological connections or their “significant nexus” is because the main objective of the Clean Water Act is to restore and maintain the chemical, physical, and biological integrity of the nation’s waters. So you can see it would be pretty hard to maintain and restore the nation’s waters if the upstream and adjacent waters connecting to them are going “all to heck.” It is kind of like the butterfly effect. How does the larval cycle of an invertebrate in an adjacent wetland affect the welfare of the downstream fish population?  And it’s kind of like the six degrees of separation too. How does the water in a downstream river make its way there through a whole set of hydrologic connections, like tributaries and shallow aquifer recharge.

So the determination of connection through chemical, physical and biological processes is what the scientists at EPA considered in determining what would be covered under the Clean Water Rule. The report is a compendium of science from the scientific literature, meaning peer reviewed journals in which scientists publish their findings. So EPA performed no new science to make their determinations. EPA only looked at the work of others and synthesized it in about a 500 page report which reads like a textbook. In fact you could probably use it as a textbook on hydrologic connectivity.

Textbooks do a lot of defining of terms. It’s sometimes like learning a whole new language. And EPA’s report does a lot of defining of terms as well. One of the chief terms they defined was the definition of connectivity. EPA defined it as “the degree to which components of a watershed are joined and interact by transport mechanisms that function across multiple spatial and temporal scales. Primary transport mechanisms are surface water and groundwater flows, transport and transformation of physical and chemical materials and movements of aquatic and semiaquatic organisms.” Well that is a mouthful. My interpretation of this definition is that EPA is going to consider the various waters in a watershed connected when waters serve to increase or reduce chemicals downstream, when they impact on the supply and other physical attributes of downstream waters, and if there are organisms like fish that use upstream and adjacent waters to spawn, feed, and all the other things organisms do.

Today’s post is the first in a series on EPA’ Connectivity of Streams and Wetlands to Downstream Waters. The next posts will cover how EPA uses their definition of connectivity in determining through the scientific literature what tributaries, what riparian and floodplain wetlands, and what non-riparian, non-floodplain wetlands are part of the Clean Water Rule.

If you read my last post on the Clean Water Rule then you are probably not too surprised that after the Environmental Protection Agency issued its final Clean Water Rule back in June 2015 that everyone got lawyered up and sued the EPA. I certainly wasn’t surprised. Nor was I surprised about the entities who sued EPA over the new Rule. Specifically it was a bunch of state governments – thirteen of them to be exact. All of the states who sued are west of the Mississippi River, except for Missouri. I don’t know why Missouri joined the lawsuit. Maybe they were just feeling frisky that day. Generally no one in the eastern part of the United States cares so fervidly about water issues as they do in the west. I’ll drag out that old bon mot about water in the west often attributed to Mark Twain: “Whiskey’s for drinking; water is for fighting.”

So a little background on why western states are so up in arms about the Clean Water Rule. As you may recall, the new Clean Water Rule seeks to clean-up the definition of what is and what is not a “water of the United States.” Numerous cases have been dragged up to the Supreme Court regarding the federal government’s interpretation of waters of the United States. The cases are primarily a result of the federal government issuing violations to certain parties who failed to acquire dredge and fill permits under the Clean Water Act. The last time such a case went to the Supreme Court, there were a number of Court members who were a little perturbed that EPA has never cleared up the definition. So EPA set off to write a Rule to clarify the meaning of waters of the United States.

A number of states in the west did not like the fact that EPA was writing a Rule. They didn’t like the Rule when it came out. And they have designated the Rule as a “federal water grab.” Water is managed by the state. In the west, where there is very little water, the state’s right to manage water is inviolate in their eyes. Why? Because, water is a local issue. This inviolate right to manage water is codified in Water Rights legislation throughout the west. There are State Engineers and government boards within the western states that manage the water within the states. Who has the right to each drop of water has been dissected and discerned by these government officials and boards. Still there are constant fights among water users. Lots of the water rights issues end up in court. The state governments are sensitive because they are dealing with a bunch of riled up citizens who have to fight and scrape for their share of water. So you get the picture, anything to do with water and water management in the west is a contentious issue.

Now put on top of that a new federal rule that is fairly encompassing and somewhat confusing. Although EPA sought to clarify the definition and the actual Rule itself is short, there was simply a lot of concern by the states involved in the lawsuit that the Rule was too encompassing. Personally I found the Rule pretty confusing and in seeking to understand it a little better I read the 300 page preamble. Preambles to Rules can be lengthy, but regulators use them to determine what the Rule actually means and how it was derived. By the time I finished reading the preamble I was thinking of the difficulty of determining on the ground what the Rule proposed. For example the Rule says tributaries to rivers are waters of the United States. That makes sense. Any waterway intersecting a river will affect the water quality, the biota in the river, and the physical nature of the river (size, flow, etc.).

The Clean Water Rule went on to include perennial, intermittent and ephemeral tributaries as covered under the Rule. Perennial streams are the ones that flow with water in the surface and alluvium most of the year. Intermittent streams are the ones that flow with water in the surface and alluvium some of the year. Ephemeral streams don’t have regular flow of water in the surface or in the alluvium. Ephemeral streams are precipitation dependent. They are the conduit of what my dad used to call gully washers. We all know that those gully washers can be sudden and huge. The precipitation event may not happen for long, but it can wash a ton of stuff into a gully and downstream into a river. So it makes sense that they are included as waters of the United States because such events can affect water quality. But then the preamble goes on to say that tributaries are characterized by the presence of physical indicators of flow: bed, banks and ordinary high water mark.

EPA uses the Army Corps of Engineer’s definition of ordinary high water mark: “The term ordinary high water mark means that line on the shore established by the fluctuations of water and indicated by physical characteristics such as a clear, natural line impressed on the bank, shelving, changes in the character of soil, destruction of terrestrial vegetation, the presence of litter and debris, or other appropriate means that consider the characteristics of the surrounding areas.”

This is not a new definition. It has been used for a long time. The Army Corps of Engineer’s guidance on how to determine the ordinary high watermark can be found in their Regulatory Guidance Letter No. 05-05 issued back in December 2005. Making the determination is tough enough in the east where there is a lot of water flow even in ephemeral streams, but trying to make that determination in some of these ephemeral streams in the west? I could see it as a bit hard. I suspect there might be a lot of fighting between two reasonable hydrologists in many such cases.

Frankly I kind of got lost in the preamble on the EPA discussion of adjacent waters. Adjacent waters are included in the definition of the waters of the United States. Adjacent means bordering, contiguous or neighboring rivers and streams, like wetlands, ponds, lakes, oxbows impoundments and the like. EPA gives three further definitions of what is covered. I won’t bore you with what those are. They are quite specific.  But then EPA goes on to say, well there are some adjacent waters that will have to be determined whether they are a water of the United States on a case by case basis. These include prairie potholes, Carolina and Delmarva bays, pocosins, western vernal pools in California, coastal prairie wetlands in Texas, and (oh by the way) waters within the 100 year floodplain of navigable waters and within 4000 feet of the high tide line of navigable waters. Well if you include all that in a case by case designation, then how can you consider the Clean Water Rule as a clarification of the meaning of waters of the United States.

EPA says in writing the Clean Water Rule that they used not only a compendium of scientific analysis from peer reviewed scientific literature, but they also used their forty some years of technical expertise in implementing the Clean Water Act.

EPA’s Clean Water Rule was supposed to take effect on August 28, 2015. What happened instead was that a Federal District Court in North Dakota issued an injunction against implementation of the Clean Water Rule.  That means that the Clean Water Rule will not be implemented until the lawsuit brought by the 13 states is resolved in court (probably the Supreme Court).

I don’t blame EPA for a confusing Rule that broadly captures so much into the definition of waters of the United States. This is tough stuff and not an easy call. I’d say it’s what happens when you have to regulate natural processes like rivers and streams to make sure that the water quality is good and supporting a healthy group of biota, like fish. It is not at all clear-cut. I am going to read the EPA’s Science Report published as a support document for the Clean Water Rule. I suspect it will inform us of the many scientific certainties and uncertainties that EPA had to address in writing the Rule.  I will be writing posts on the report. The EPA report is titled “Connectivity of Streams and Wetlands to Downstream Waters.”