S Montana stream 333«9162nanagenient guide ESOnsn for landowners* 1995 nanaeers and stream users r-.-.f^.^V-'Vi^i; :=*^ ft, .V - iy^^^' vwT- -~^ • J)?'- M ^s^ alia --r «ert? landowners, MMAgers and Strem Users *■ 1 -r MONTANA STATE LIBRARY 3 0864 0010 7963 4 hLUvdiicno u 'earns SECTION AJjoiii SU What Is a Watershed? 2 Watersheds, Geology, & Climate 3-4 Features 5-7 Stream "Personality" 8-9 Stream Types 10-13 SECTION A_l)^ tit Kestoratton Watershed Planning Stream Restoration Permits You'll Need 14 14 15 16 SECTION WIq^-I^^ ng With Streams 17 Riparian & Streamside Vegetation 18 Water Quality 19 Floodplains 20 Channels 21-24 - Constrictions 21 - Widening 22 - Entrenchment 23 - Straightening 24 Streambed Disturbance 25 Dewatering 26 Methods & Costs of Streambank 27 Alteration & Stabilization ii '■ A Final Word IS Stream Words Credits 1 30 ■ Acknowledgments Cooperative Funding Montana Fish, Wildlife & Parks Montana Dqjartment of Environmental Quality Montana Department of Natural Resources & Conservation Montana Riparian & Wetland Association U.S. Environmental Protection Agency U.S. Forest Service Northern Region Project Sponsors Montana Association of Conservation Districts Montana Department of Environmental Quality © 1995 by the Montana Department of Environmental Quality. All rights reserved. Printed in the United States of America by Color World of Bozeman, Montana, on recycled pajser. You may reproduce or copy any portion of this booklet after notifying the Montana Depart- ment of Environmental Quality. Please acknowledge this publication as the source. December 1995 Montana's streams vary ivith the landscapes they flow through — some streams tumble down from high mountain valleys through narrow canyons, others wind lazily through wide valleys and across the plains. As you start to recognize and understand stream types, you will see that different streams or reaches of the same stream respond differently to the same activity, depending on their natural characteristics. ^ treams link Montana's mountains and plains, public and private lands, and upstream and downstream neighbors. People can make sound management decisions if they understand how streams work. This guide provides helpful background information for landowners and managers, resource professionals, state and local decision-makers, recreationists, and others interested in streams. All Montanans are affected by how streams are managed — whether for agricultural, domestic, or industrial uses or for our enjoyment of wildlife, fisheries, or water-related recreation. Flowing water is a shared and limited resource which requires cooperative management among many users and interests. Good stream management makes good Sense. Healthy, stable streams are the most economical and productive for all. In Section One, "About Streams," you'll learn about the characteristics and behavior of healthy streams. Section Two, "About Restoration," discusses your role in management and restoration decisions, what permits you'll need, and which agencies to contact. Section Three, "Working with Streams," focuses on specific examples of stream problems that you might encounter. ! About Streams What is a Watershed? A loatershed is the total land area being drained by a particular stream or river. Montana has 16 major watersheds (also '^* called river basins), which are pictured below. These ivatersheds contain many, many smaller watersheds. Montana's Major Watershed Basins Koolenai{ ^'-^O'T -^ \Flalhead\ ^"""' Lower \ I Clark l/\ A, Fork ~l ^-""^^T-, Missoiiri- \ } Upper p I""- ■^ \ Clark f ^"""' 1 } Fork I iMwer Missouri f Middle ( Missouri iMwer V Yellowstone Many smaller watersheds, such as the Musselshell River Basin shown beloiv, make up the huge Missouri River watershed. All streams within a watershed loork together to move water and sediment downstream. ■ Watersheds, Geology, and Climate Stream channels are formed by the flow of water and the load of sediment they carry. The amowit of water and sediment moving through a watershed depends on climate and geology. Climate determines: • amount of rain and snow, and the timing of runoff • rate of evaporation • type of vegetation • rate of groundwater recharge • rate of erosion • how quickly bedrock weathers to soil Geology determines: • rate of erosion • potential for sedimentation • stream bank material • permeability and porosity of soils • aquifer depth and recharge rate • water chemistry and biological productivity Precipitation in Montana falls unevenly — most falls in the western third of the state, west of the Continental Divide. Because of this, more water flows out of the state in the Clark Fork River than in the Missouri River, which collects water from the eastern two-thirds of the state. Average Annual Precipitation Peak flow, the greatest flow in a stream, typically occurs in western Montana during late spring and early summer when snow melts in the mountains. In eastern Montana, some streams experience high flows after intense rainstorms in spring and summer. Base flow, the lowest flow in a stream, typically occurs in western Montana from late summer through the winter. Flows may go entirely below ground during dry periods. Average Annual Runoff Width of stream tine corresponds to top width of channel. IVIean annual discharge, in thousands of cubic feet per second, Is represented by channel cross section in blue. 10 ^ ^ ^ 20 30 40 Less than 14 inches 14 to 30 inches More than 30 inches Forested, mountainous watersheds in northwestern Montana receive 60 to 100 inches of precipitation per year and have more perennial streams; grassy plains watersheds of eastern Montana, which receive 8 to 12 inches of precipitation, have more intermittent and ephemeral streams. A RaiLTLSTR FAMS. Watersheds, Geology, and Climate Montana's streams are as diverse as the landscapes through which they flow— from the forested mountains to the grassy plains. J'4i ^^""^ ^^^^ stream ^^^H flows through a steep, narrow valley, it runs relatively straight and fast, cascading and scouring out pools. Some streams flow slowly through wide, flat valleys. Wetlands and riparian areas form along the banks and occupy floodplains, creating rich streamside habitat. Stream banks are of finer-textured soils, hold more water, and may support a greater diversity of vegetation than high mountain streams. S E C T I ° ^ / Features Components of a Healthy Stream System • stable stream channel • active floodplain • groundwater healthy riparian (streamside) vegetation high quality waters Physical View of a Stream flood-prone width — active or bankfull channel ^'l RaitTLS:TR FAM^ Groundwater is the water that seeps through the spaces between soil particles and flows into aquifers. Aquifers are saturated zones of sand, gravel, or fractured bedrock underlying the valley. Porosity is the volume of the spaces or pores between particles in an aquifer. It varies with the type of material present and determines how much water the aquifer can hold. Permeability is the rate of water movement through the soil or aquifer. It is much faster in materials with large pores, such as gravels and sand, than in materials with small pores, such as clays. During dry periods, groundwater may RECEIVE water from the stream. Gaining Stream • baseflow stage water table During wet periods, groundwater ADDS water to the stream. Gravity is the driving force behind rivers, causing water to flow downhill, to seep into streams when the water table lies above the streambed, and to seep into the ground. Healthy Riparian Areas ...Healthy Fish Populations In a healthy riparian area, there is an interrelationship between vegetation, pools and riffles, and fish. Working together, these components produce a healthy environment for fish and protect water quality. <". ■m 'o:-~ >fif>^/ •o -■ Vegetation : • provides stability • protects banks • provides cover and food for fish <^-''fB^. ^^ Pools and riffles provide cover and foodforfish. ^1 Floodplains Flooding is a natural stream process. A floodplain — land next to a stream where water overflows during floods — is an important part of the stream system. The Role of Floodplains • Spread out and slow flood waters, reducing their erosive force. • Slow water enough so it can seep into soil, recharge aquifers, and slowly return to stream. • Filter sediment that settles from the water, building deep, fertile soils. The Biological Richness of Riparian Areas and Streamside Wetlands 1. Riparian areas contain a diversity of plants. 2. They provide wildlife with: corridors for migration cover from weather and predators • breeding, resting, nesting, and foraging areas ARainLS.TRFAMti What's Your Stream's Personality? These characteristics determine many stream- types, each with its own "personality. " *^, What's the most common ■ material making up the -*- channel and bank? Silt/Clay smooth betzveen fingers Channel and bank materials are critical character- istics of a stream. They determine: • sensitivity to disturbance and potential for erosion Sand feels gritty recovery potential Gravel fits in hand ' ability to support vegetation • role of vegetation in stabilizing stream channels • amount of channel roughness to slow stream flow and reduce stream energy Cobble 1 Channel and bank materials 2 Sinuosity 3 Channel gradient 4 Floodplain 5 Channel shape Other important stream characteristics not illustrated here: 6 Floiv timing and amount 7 Amount of sediment By understanding the combination of characteristics that make up your stream's personality, you can determine appropriate management practices. Changing any of these characteristics without careful planning can cause unwanted changes in the stream. 2 How sinuous is the channel? Sinuosity refers to the amount of curvature in a stream channel. The increased length of a highly sinuous channel helps to dissipate stream energy. Shorter and straighter channels possess more stream energy and erosion potential. highly sinuous straight slightly sinuous (meandering) Boulder you may have to climb over 3 What is the gradient of the channel? The steeper the channel gradient, the greater the water velocity and potential for erosion. Greater than 4% 2-4% less than 2% ^1 4 Is a functioning floodplain present? Does your stream overflow its banks every few years? If not, the stream may be changing because of alterations in the watershed. Without a floodplain, the stream's energy is concentrated in the channel during flood flows. This increased energy may either downcut the channel or erode the banks. To determine the edge of the bankfull channel, which is the beginning of the floodplain, look for: • change in vegetation • slope break • change in particle size of bank material • undercuts in the bank • stain lines or lower extent of lichens on boulders • top of stream or channel bars Downcut stream with no floodplain All of these characteristics influence the personality of your stream under natural conditions. Stream types may be changed by our alterations and activities. Stream with functioning floodplain 5 What is the channel shape? Channel shape is mostly influenced by: • quantity of water • gradient/valley slope • sediment load • amount and type of vegetation • type of bank and bed material • human activities that directly alter channel or watershed IBBSHI HBHS WKtKt^ Common channel shapes A RailTLS^TR FAM^ Healthy Stream Types Common in Montana Mountain Stream • steep slope (greater than 4%) • V-shaped valley • vertical erosion (little horizontal) • narrow floodplain and riparian area • narrow, deep channel • straight to slightly sinuous • often a series of descending pools 10 w^ ^1 Healthy Stream Types Common in Montana Wide Valley Bottom Stream • slope less than 2% point bars, riffles, pools • flood flows spread over broad floodplain and riparian area • sinuous • wide, shallow • horizontal (lateral) erosion 11 ARClltTL^iTRFAM^ ■ Unhealthy Stream Types Common in Montana Some Indicators of Unstable Stream Channels • channel widening • unvegetated, eroding stream banks • channel downcutting • increased silt/clay on channel bottom _ • inability to overflow banks during spring runoff • increase or decrease in water supply • increase or decrease in sediment supply Wide, Shallow Stream • sinuous • slope <4% flood- prone area ■~fM'-' '^ssn ^^ f^; ^ ^/ ^■bankfuU stage #// ■^ '•?. ^. prone area -^^ treatn ■ than 2% multiple shifting channels herfvy sediment load erodes laterally wide, shallow little aquatic habitat Some braided streams occur naturally, such as in a glacial headwater environment, but they most often result from human activities that contribute excessive sediment to the stream. 12 t C I I O N .1 Unhealthy Stream Types Common in Montana Entrenched/ Incised Stream • slope 2-4% • gully-shaped channel • no access to floodplain 13 -About Restoration Watershed Planning Many of the healthy characteristics of this impacted stream have been lost . . . Watershed planning begins when citizens of a river basin evaluate the condition of their land and water resources. They then develop a plan to restore or keep the resources in top-notch condition while meeting most social, economic, and ecological needs in the basin. Steps in watershed planning: • Form a watershed planning committee that includes a variety of interests and occupations in your basin. • Hold a public meeting to identify the resource concerns in the basin. • Form a technical advisory team composed of agencies and organizations that can help you gather information and find solutions. • Conduct an inventory to determine the total stream miles and condition of critical reaches in the watershed. • Prepare a plan, reviewing the range of alternatives, setting priorities, evaluating cost efficiency and project effectiveness. • Present the plan to the public to review and adopt. • Implement the plan using financial and technical assistance available from a variety of sources. • Review the plan and progress annually. Stream restoration is part of watershed planning. If something is "broken" or out of balance on a smaller stream in the watershed, it may be fixed by a simple management change, or it may require a realigning of channel sections. Think of it like an automobile when something goes awry — the problem could be a broken belt or a blown engine. So before beginning a restoration project, be sure to identify the cause of the problem and address that first. . . . hoivever, after careful planning, a nearby reach of the same stream has been restored. 14 Eight Steps To Restore A Stream Get to Know Your Stream • Your first step is to familiarize yourself with your stream and its combination of characteristics. Take a walk along, or maybe even in, your stream. # Assess Your Stream & Streamside Area • Identify healthy stream reaches. • Identify problem areas. • If necessary, seek assistance from a resource professional. iH • Use a stream channel and riparian area monitoring form available from local resource agencies. Quantify Problems: Tor example, ask • How many feet of stream bank are bare of vegetation and eroding? • How many feet of stream bank contain noxious weeds or species with poor root structure? • How healthy is the fish habitat? Are • pools and riffles adequate for fish reproduction, rearing, and overwintering? Prioritize Problems to Address • Read Section 3 about common stream problems and their solutions. • Discuss the stream problems with a stream management specialist. • Determine which problems can feasibly be corrected by your actions. • Which problems need the help of your neighbors and community? To ensure successfid restoration, yon need to thoroughly plan and carefidly implement the restoration. The steps on this page will help you achieve your goals, as will the agencies listed on the next page. Establish Your Objectives- Objectives should be realistic. If you include measurable standards and a^ workable time frame, you can better gauge your success. For example, you can aim to increase native streambank vegetation by 50 percent in five years. Develop a Work Plan • Evaluate a range of alternatives. • Compare the costs for different management practices and restoration ^alternatives.w Implement Your Work Plan • Obtain all necessary permits. • Adopt new management practi^. • Improve stream channel stability by actions such as: — installing tree revetments — planting streamside vegetation • Seek qualified contractors to assist you. Monitor the Restoration • Annually evaluate whether you are meeting your restoration objectives. Assess the need for modification and maintenance. Share your observations with stream management professionals so that we all learn how to manage and restore streams successfully. 15 A liOJiTJi i-XJfm/iTJOM SECTION ■ The Permits You'll Need If you are planning a management activity in or around a stream, you will probably need a permit from a local, state, or federal agency. Use this diagram to determine where your project will take place — streambed, stream banks, wetlands, or floodplain — and what permits you need for activities in that part of the stream. Contact the appropriate government agency for information about acquiring necessary permits. Before issuing a permit, the agency checks to make sure that your plans are technically feasible, have limited or mitigated impacts, and do not affect your upstream or downstream neighbors. B, C, D, E, K A, B, C, D, F, I, J, K A,E,F,G,H,I,J,K- streambed B,C,E,G,I,K- -wetland- streambank- floodplain — Using this diagram, determine where your activity will occur. The letters refer to the permits listed below. Permit Government Agency Phone A Montana Stream Protection Act (124) Montana Fish, Wildlife & Parks 406-444-2449 B Storm Water Discharge General Permits Dept. of Environmental Quality 406-444-2406 C Streamside Management Zone Law Dept. of Natural Resources & Conservation 406-542-4300 D Montana Floodplain and Floodway Dept. of Natural Resources & Conservation 406-444-6610 Management Act E Short-term Exemption from Montana's Dept. of Environmental Quality 406-444-2406 Surface Water Quality Standards (3A) F Montana Natural Streambed and Montana Assn. of Conservation Districts and .... 406-443-5711 Land Preservation Act (310) Dept. of Natural Resources & Conservation 406-444-6667 G Montana Land-use License or Dept. of Natural Resources & Conservation/ .... 406-444-2074 Easement on Navigable Waters Special Uses H Montana Water Use Act Dept. of Natural Resources & Conser\'ation 406-444-6610 I Federal Clean Water Act (Section 404) U.S. Army Corps of Engineers ,. 406-444-6670 J Federal Rivers and Harbors Act (Section 10) ... U.S. Army Corps of Engineers 406-444-6670 K Other laws that may apply, Various agencies depending upon your location & activity For more details, request "A Guide to Stream Permitting in Montana" from the Montana Association of Conservation Districts, 501 N. Sanders, Helena, MT 59601; 406-443-5711. m 16 Working with Streams r^ SECTION r '>t;^7'-m'^*!J'i'^w^^■ •_■; -•.< *~";3iTKHOisaarJ f €S^ ^\^n\ ^mJ ^^ f you live next to a stream, your ^^^H streamside management activities ^^^H can directly affect stream health and function. This section examines some of the most common ways that we impact streams and change their features and behavior. Most problems can he traced hack to something that has changed the supply of water or sediment in the stream or altered the stream channel or banks in some way. We can often lessen the impact through preventive measures or adjustments in our management of the stream. When making streamside management decisions, you should ahvays practice preventive thinking because stream degradation is much easier and cheaper to avoid than to fix. You can prevent stream disturbance if you understand stream behavior and the "personality" oiyour stream. LOOK FOR THIS ALERT— it reminds you to ahvays seek guidance and obtain permits from your local land management agencies before work in or near a stream. Always refer to the chart on page 76 before beginning a project. 17 WjOJiJONGJAlJTJI JSth LA Riparian & Streamside Vegetation How We Impact Vegetation Overgrazing by livestock or wildlife Spraying herbicides Operating heavy equipment in riparian areas Building roads Clearcutting streamside areas Farming to the edge of a stream Allowing invasion of non-native species Removing riparian vegetation Effects of Impacting Vegetation Increases bank erosion & failure Widens channels; decreases depth Disrupts streamside plant communities Increases invasion of non-native plants Lowers water table Makes stream banks more susceptible to livestock trampling and erosion Increases water temperature Speeds runoff Reduces trapping of sediment and other pollutants Reduces livestock forage Increases bank damage due to icing Decreases valuable real estate Decreases fish and wildlife cover Maintaining healthy vegetation should be your first priority when managing stream and riparian areas. Stream behaviors, such as channel widening and bank erosion, are influenced by the amount and kind of vegetation on stream banks. Healthy stream banks are covered by deep, densely rooted streamside vegetation that binds soils. Streambank vegetation also creates friction that slows stream flows. Removing vegetation, or replacing it with riprap or cement walls, increases stream velocity and sends more erosive stream energy downstream. Lessening Our Impact • Do not remove riparian vegetation • Control noxious plants • Manage grazing intensity, vary season of use, and provide sufficient rest to encourage plant vigor and regrowth • Ensure sufficient vegetation during spring runoff or peak flow to protect stream banks, dissipate stream energy, and trap sediments • Control the timing of grazing to prevent damage to stream banks when they are wet and most susceptible to trampling • Re-establish native and appropriate non-native plant species 18 SECT Water Quality Sediment is the number one polluter of streams in Montana. Other pollutants include chemicals, pesticides, herbicides, nutrients, minerals, and salifjiti/. Human-caused changes in temperature, such as ivarming or cooling, are also considered pollution. AU of these pollutants limit the way that water can be used by humans and other life. How We Impact Water Quality • Point source pollution enters a stream from a known point, such as a discharge pipe, and is usually municipal or industrial in nature. It accounts for approximately 10 percent of water pollution in Montana. • Non-point source pollution enters streams from dispersed areas, such as windblown sediment and runoff from roads or crop lands. It accounts for 90 percent of stream pollution. Non-point source pollution is usually associated with poorly planned land management activities. ^ess. Effects of Our Impact • Can eliminate entire aquatic communities and make water unsafe for human use • Increases temperature, which can biologically suppress stream systems • Increases costs of water treatment, and reduces usefulness of pumps and ditches • Affects water quality downstream because effects tend to accumulate throughout watershed ^- ^nent assess process the "^SSec;^,^ "''"""' ^ha,.r:''^^n^s. ^Okfof. species Ti, "^^(^earp , Uiater -abs, boater ^''/. a '8 this ■s.oll'^Sanic "fe cal,ZS"^isrns "lualit ojce y. 'ndh 'ator good cates Lessening Our Impact Protect riparian areas- nutrients from runoff -they filter non-point source pollution such as sediments and Adopt the Best Management Practices (BMPs) for agriculture, grazing, timber harvesting, and mining to minimize pollutants entering streams and rivers Obtain permits before starting any activity that may impact water quality 19 i^ ] 4 'iJJi KJN(lA\flTji_6TJi hA MSI Floodplains During a flood is not the time to figure out that you built your house in the floodplain, too close to a stream. Floodplains are critical components of a healthy stream or river system. They provide room for flood waters to spread out and soak in to recharge groundwater and to reduce the flood's erosive energy. The fertile soil of floodplains enables abundant vegetation to grow and provides impwrtant wildlife habitat. If you armor your stream bank and raise its height to prevent flooding on your land, you are sending more erosive energy doivnstream to your neighbors. ?€^Al^t! How We Impact Floodplains • Poor agricultural and grazing practices • Residential and commercial construction • Protecting property by building dikes, levees, and retaining walls; by installing riprap; and by eliminating overflows into side channels Effects of Our Impact • Decreases ability of floodplain to disperse stream energy during flood flows, which: — Increases energy of flood downstream — Increases peak flood levels — Increases bank and bed erosion on neighboring property • Decreases vegetation cover, which may cause spring runoff to occur earlier and over a shorter period of time, and to produce higher peak flows • Decreases ability of floodplain to recharge local aquifers, which: Effects of Our Impact (continued) — Decreases riparian vegetation — Reduces channel flows in drier months • Reduces aquifer volume • Increases size and frequency of floods, causing more damage to property and stream channels • Increases pumping costs Lessening Our Impact • Avoid construction in the floodplain • Do not restrict floods from flowing into side channels without consulting stream management experts and obtaining a permit • If construction activities must occur on floodplains, minimize disruption of the soils and vegetation • Use agricultural methods that minimize impact on floodplain • Establish greenbelts or stream protection corridors in floodplains 20 Channel Constrictions A stream channel's cross section reflects the amount of water and sediment carried by the stream. If you change the stream's width by either narroioing or widening it, you alter its ability to transport water and sediment. Such changes cause other problems both upstream and downstream. How We Impact Stream Channels • Building bridges, berms, levees, roads, and railroads • Cutting off side channels • Installing culverts • Placing debris or riprap along the banks Effects of Our Impact • Can increase the erosive energy at a particular location, which: — Increases erosion of stream bed and banks — Creates down-cutting (incision) of channel, which leads to lowering of local water tables and loss of riparian vegetation • Creates low-energy backwater — Increases filling of sediment — Increases bank erosion — Elevates flood flows Lessening Our Impact • Avoid confining channel • Ensure that stream crossings, such as bridges and culverts, are large enough to pass flood flows • Replace undersized stream crossings • Stabilize erosive areas that add sediment to the water 21 \A(DJiTONGJ\¥JTJiJSTJi hA M5_ Channel Widening If your stream lacks pools and riffles, and seems unusually shallow, it may have an overly wide channel. Channels begin to widen if banks are trampled, vegetation is removed, or the channels become loaded with more sediment than they can carry. The sediment settles arid begins to fill the channel. The same amount of water is now trying to flow through a smaller channel. As a result, the channel begins to widen. How We Impact Channel Width • Overgrazing and trampling by livestock • Causing any degradation of the upstream banks, floodplains, or riparian areas • Increasing amount of sediment either upstream or in immediate area • Increasing flood flows by decreasing vegetation upstream • Transferring water from one stream to another within the same watershed (interbasin water transfer) Effects of Our Impact • Increases bank erosion • Increases need to treat drinking water • Increases maintenance of irrigation pumps, diversions, and ditches • Increases sediment loads, which encourages erosion and widening further downstream • Decreases vegetation • Decreases fish habitat by filling in pools and spawning areas and by warming water in summer and icing water in winter • Eliminates riparian habitat Lessening Our Impact • Protect riparian vegetation • Stabilize upstream erosion by replanting vegetation • Manage riparian areas to prevent erosion •#^ Nv^^tl M 22 * Channel Entrenchment Entrenched channels are deep with high banks. Entrenched channels are most frequently found in highly erodible terrain. Changes in a channel's hydrology, sediment supply, or erosive energy can cause entrenchment, which is also called downcutting. What Causes Entrenchment? • Straightening or shortening a channel • Decreasing sediment supply, such as by trapping sediments in upstream reservoirs • Increasing channel's water supply Effects of Entrenchment • Lowers level of local water table to new stream elevation, which: — Changes streamside plants and affects fish habitat and stream flow — Impacts irrigation diversion and groundwater wells • Eliminates access to the floodplain, which increases stream energy and bank erosion • Reduces aesthetic values and recreational uses • Reduces property value • May increase water supply to a channel Lessening the Impact • Prevent downcutting by protecting channel and banks from erosion, and by maintaining healthy vegetation along stream banks • As soon as you notice downcutting, consult a stream management specialist for help • Conduct a stream inventory or tour the upper watershed to identify potential problems 23 1 4 ^0j< jcjMjlJ \n TjiJSrji la M5_ Channel Straightening Why Streams are Straightened To reduce the number of highway and railroad crossings To develop land more easily along streams To control overbank flows To protect property by eliminating channel migration P^M^ Streams that flow through steep, narrow valleys run relatively fast and straight. But once a stream moves into less steep and less confining land forms, it slows and begins to curve and meander. When the natural sinuosity of a stream is altered, the stream becomes steeper and its flow increases in energy. The stream reacts to these changes by making adjustments. Effects of Our Impact • Eliminates meanders and shortens stream length, which increases slope and reduces natural energy dissipation • Increases velocity of water, which increases erosion downstream • Increases flood intensity — Speeds movement of peak flows — Eliminates storage capacity of stream • Decreases channel stability and increases channel migration as the channel attempts to come to a new equilibrium; this also increases problems upstream and downstream Lessening Our Impact Stream managers rarely recommend straight- ening channels. Instead, they suggest these alternatives: • Plan roads and other developments away from streamside areas Control upstream sediment sources to reduce downstream instability Stabilize channel banks •is ■ni'^S "anient 1= age' tlvcit ar^^^ trecii^^'^'^eVc'^'^'lMrniriS' Hcin^' c\s' traig' Hten If your stream is already straightened, consult a stream management specialist about restoring straightened sections to their original channel shape and pattern. 24 SECTION Jj- Streambed Disturbance f^^^^mv. In Montana's dry climate, streams usually lose xvater as gravity pulls water into the ground. The material making up the streambed controls the rate that water is lost from the stream. Fine sediments often seal a streambed and slozo the loss of stream water If heavy equipment or other activities disturb the fine sediments, water can seep into the aquifer at a much higher rate. This can cause an entire reach of the stream to go underground for a while. How We Impact the Streambed Seal • Operating heavy equipment in the stream channel • Removing or disturbing channel bed materials Placer mining, for example, impacts streambed seals in both of these ways Effects of Our Impact • Increases water seepage into aquifer • Reduces water available for in-stream use and downstream users • Increases water temperature in the summer Lessening Our Impact • Operate heavy equipment in the stream channel only when absolutely necessary • Use irrigation diversion alternatives that do not require operating heavy equipment in stream channels 25 1 A(OJiJONGJVJTJiJSTj< hA MB_^ Dewatering How VJe Impact Water Levels • Over-appropriating water • Building dams • Storing water in reservoirs • Transferring water from one basin to another Effects of Our Impact • Disrupts natural life cycles of animals such as trout that depend on seasonal flows • Decreases aquatic habitat by decreasing amount of water and vegetation • Changes streamside vegetation from native riparian species to less-productive dryland species • Increases water temperature • Can alter natural cycle of high spring and low winter flows • Can cause ice buildups if winter water flow is low; this causes ice jams that can scour stream banks, fish habitat, and adjacent properties In many watersheds within Montana, more water rights exist than loater. Because of this over-appropriation of water, streams are dewa- tered on a regular basis by people exercising their water rights. Dewatering occurs every year but is especially intense during droughts. Lessening Our Impact • If possible, provide more water for in- stream flows • Use irrigation water efficiently • Use only legally appropriated water shares • Try to manage reservoirs for water flows and fisheries • Consider leasing water rights for in- stream use Hunter floras. Marufp^lf; S^^ '"' '^^ rout are adapted it^hZ"! i ^'^'' '"'^ "' tme their reproducVoTto'"^^^^^^^^ ^"^ seasonal flozos. Reservn, rn -^'^ '"'^'^ ^«« result in strea7Z'J'f'"S or storage greatly reduced Tn J,l^ ^'''^^ered or l in volume. flows . and J„«„»»o«.«"j;,.„„ sen-ice. Resource Conser 26 SECT , O N ^ J 1 1 ■ Methods Sz. Costs of Streambank Alteration & Stabilization ^ Tlte cost of bank stabilization measures varies. You can use this chart to compare costs, advantages, and disadvantages of different strategies. i Stabilization Measure Advantages Disadvantages Costs * ' Management Changes Implement grazing and agricultural practices that allow vegetation to recover. Easiest to implement; natural recovery; diverse opportunities. Results take time. Low to moderate. Long-term increase in productivity may offset initial costs. Revegetation Plant native shrubs; reintroduce native grasses and sedges. Can be accomplished with hand labor; recovery of streamside habitat. Labor/cost intensive; results take time; need riparian expertise; may need short- term change in land use. Low to moderate, $.50-$10/foot. Costs reflect labor, availability and cost of plants. Recontouring Increase streambank slope, then cover with erosion blankets and replant native vegetation. High chance of success; recovery of riparian habitat. Requires design and installation expertise, heavy equipment, and labor. Moderate to high, $10-$100/foot, depending on bank height and intensity. Riprap Rocks and boulders cover banks. Reduces vegetation: mitigate by adding logs and/or revegetating. You must consult with government agencies if considering riprap. Very stable banks. Permanent loss of riparian habitat; may increase velocity and downstream erosion. Moderate to high, $40-$60/foot, depending on local availability of rock. Deflector Structures Jetties and barbs, usually constructed with natural materials, redirect water from unstable banks. Not recommended for everyday bank erosion problems. You must consult with government agencies if considering deflectors. When well designed, provides long-term stability. Difficult to design and install; may cause new problems; unnatural appearance. Moderate to high, $100-$ 1,000 per structure. Revetments 1 Organic version of riprap using bundles of brush, roots, or trees. Tires, cars, and other debris are prohibited as bank protection. Uses natural materials; easy to install. Not effective in high-energy streams. Results take time. Moderate, $5-$25/foot. Channel Realignment 1 To restore natural functions. Extreme measure; requires careful consideration. Quickest recovery to full potential; replaces all functions. High cost; must use professional. Moderate to high, $10-$70/foot. % * NOTE: These costs are used for comparison only and will vary depending on actual circumstance. j ^ ■ 27 A // ontanans recognize we have a rich natural resource in ~ * — the state 's streams. They provide water for us, for fish, for wildlife, and for plants. They also provide us, directly and indirectly, with jobs and recreation. We (ire also hecoiuiiu^ ciwcire of the vdliic of riparian areas — Uie area.s adjcucnl lu Mivuiit.s^o the aquatic ecosystem. This guide has inlrodmcJ you to stream munagement by emphasizing the importance of understc/ftding the resoiine and preventing problems. First, the guide discussed the various stream types in Montana and their adjacent components such as floodplains and riparian areas. Secondly, the guicte focused on how to design a successful stream manage luciTt strategy. Finally, the guide described specific problems, their causes, effects, and solutions. As Chapter Three points out, the problems and solutions related to stream management can be relatively simple; they can also be quite complex. Use the resources listed in this guide to help you evaluate the streams under your care, to correct some of the problems, and to develop an effective stream management plan that will prevent future problems and protect this valuable resource. Successful stream management will leave a legacy of healthy streams to future generations of Montanans. Aquifer Saturated zones of sand, gravel, fractured bedrock, or other material under the surface that has space between particles to hold water. Bankftill width Distance between average high water mark (HWM) on each side of stream. HWM is associated with slope or vegetation changes. Channel Stream bed. Channel shape Cross-section of a channel. Deivatering Removal of part or aU of the water from streams or other bodies of water. Ephemeral stream Flows for brief periods of time as a result of snowmelt or rainstorms. Floodplain Land next to stream where water overflows during floods. Gradient Steepness or fall of slope. Habitat Food, water, shelter, and space that an animal requires. Intermittent stream Flows only certain times of the year with water from springs or runoff. Lateral erosion Where a stream erodes its banks and ultimately widens the stream channel. Meandering Highly sinuous stream, frequently winding back and forth across the valley floor. Non-point source pollution Water pollutants originating from dispersed areas, such as erosion of disturbed soils. Perennial stream Flows all year. Point source pollution Water pollutants originating from a known point, such as a discharge pipe. Pool Deeper portions of the stream channel caused by increased scouring on the outside of turns. Reach Length of stream with similar characteristics, selected for study or observation. Revetment Installation of materials such as trees, boards, etc., that dissipate or deflect the stream's energy and protect banks from lateral erosion. Riffle Shallow water with rapid current and flow broken by a substrate of gravel. Riparian areas Lands adjacent to streams and rivers where the vegetation is influenced by the greater availability of water. Runoff Movement of water over earth's surface. Sinuosity Amount of curvature in stream channel. Watershed Total land area that drains water to a given point; includes all area drained by one stream. jj^ 29 Advisory Committee Jack Thomas, Environmental Program Manager, Montana Deoartment of Environmental Quality^ j| ^^^ • Al Wippemian & Glenn ^hillips. Habitat Bureau, Montarw Fish, Wildlife & Parks Miry Manning, Riparian Ecologist, U.S. Forest Service, Northern Region -Stnv Potts, NEPA Coordinator, U.S. EmnronnientaJ Protection Agency Project Coordinators Montana Association of Conservation Districts ?■■ Dave Marti)!, Education Specialist, Montana Department of Environmcnlal Quality Joan Schumaker, Resource Specialist, Montana Department of Natural Resources & Conservation iaR'i< Special Thanks To The Following People Who Allowed Their Material To Be Adapted For This Plb ligation Scott Gillilan, Hydrologist, Interfluve, Inc. Bob Logan, Extension Forester, Montana State University Extension Program Dave Rosgen, Hydrologist, Wildland Hydrology, Ind Booklet Design Media Works, Bozeman, Montana Marcia Rueter Leritz, Graphic Artist, Martha A. Loinier, Production Manager Editors Carolyn Duckworth, Editor/Concept Design, Gardiner, Montana Carole Massman, Editor, Montana Department of Natural Resources & Conservation Photos '''Srf^'oii- %. Interfluve (V, (4), (17), (19), j^l^0UMJ/S^) Montana Department of EnvirowucntaiQuaTity (12), (13), (14), (23), (2S) Montana Fish, Wildlife &Tarks (1), (3), (4), (7), (20), (21), (24). iback awer) Montana Department ofNaiural Resources & Conservation (18) Marcia Rueter Leritz (covem(TH> U.S. Forest Service, Northern Res (10), (11), (12), (m . Illustrations and Media Works, Bozeman, . Marcia Rueter Leritz, Gr^Krc .\rtist, line art sketches (2), (6), (7), (8), (9), and airbrush color on sketches and maps Montana State University Exti'ii>ion Forestry Program, line art sketches (2), (5), (6), (7), (8), (10), (11), (12), (13), (16) Natural Resource Information System, Montana Stale Library, map (2) Department of Natural Resources & Conservation, map (3) To Request Additional Copies F)irironmental Management Section Department of Enmronmental Quality P. O. Box 200901 Helena, MT 59620-0% (406) 444-2406 Conservation Districts Burcaii " '^^^^^fc^ Department of Natural Resources &(j0nsefmf P. 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