Backyard Stream Repair FAQs

Pennsylvania is a water-rich state, having over 86,000 miles of streams. Our abundance of water means that many landowners have a stream on their property. While streams are often considered a beautiful asset, many of our waterways are in need of some repair. Statewide historic deforestation, development, and increased stormwater runoff has resulted in eroding streams and property loss. To assist landowners with improving their backyard streams, the manual, Simple Solutions for Your Eroding Backyard Stream, was developed. This publication introduces straightforward approaches to better stream health, such as not mowing up to the water’s edge, planting native trees and shrubs, and reconnecting the stream to its floodplain.  The following questions and answers provide additional detail and clarification on the topics discussed in our manual and serve as a supplement to our core stream repair education found in Simple Solutions for Your Eroding Backyard Stream.

General Questions

Q: Where can I get a printed or digital copy of the Simple Solutions for Your Eroding Backyard Stream manual?

A: Go online to Simple Solutions for Your Eroding Backyard Stream

Q: What are some ways to help prevent erosion and help reduce flooding?

Simple Solutions for Your Eroding Backyard Stream, presents three solutions for addressing erosion and improving stream health. Option 1, allow the streambank to grow wild, promotes the concept of permitting native vegetation to grow, which will stabilize the banks and improve soil health to enhance infiltration and reduce flooding. The downside to this approach is that it may take a long time for the streambank to stabilize and erosion is likely to progress for many years. Option 2, plant native vegetation, uses native plants to stabilize the soil. By planting native trees and shrubs, either as live stakes or seedlings, these plants will hold the soil in place while also absorbing runoff which reduces downstream flooding. Finally, option 3, grade banks to a gentle slope and add plants, is perhaps the most effective way to address erosion and flooding if you are experiencing steep banks. By grading banks to a gentle 3:1 slope, it allows floodwater to access the floodplain where the flow will slow down and water will slowly soak into the soil. Planting trees, shrubs, and native herbaceous plants after grading stabilizes the soil to prevent erosion.

Q: If my stream has extensive high banks, does that mean I have to grade my stream? How high of a vertical bank is worth trying to stabilize with planting alone? How can "allowing the streambank to grow wild" work with a bank that is already cutting deep? Wouldn't it keep eroding?

A: While grading is the best solution to high banks, planting native vegetation will still provide benefits where it is currently absent.  Any type of bank stabilization is better than letting the bank erode into the stream.  Just be mindful of site conditions, such as soil moisture, to ensure that the species that are selected will survive. Allowing your bank to grow wild is only an improvement if you are currently mowing right up to the edge of the stream or close to it. Even an eroding stream can benefit from something more than turfgrass. 

Q: Who should I contact for help with streams that have high levels of erosion? 

A: Start by contacting your county conservation district. They will be able to discuss options with you, the permitting requirements that would be involved, and refer you to the Department of Environmental Protection (DEP) if needed. If you are interested in grading the bank to address the erosion, but the project requires more experience or heavy equipment, reach out to local contractors who are skilled in earthmoving and grading.

Q: If tree trunks or large limbs fall into a stream, should they be pulled out or will they benefit the stream? 

A: Unless these limbs or trunks are creating a safety hazard, it is fine to leave them in the stream. They will slow the flow of water and provide habitat for fish and other critters. If large trees are blocking the flow of the stream, causing flooding and a permanent and large pool, you can remove a section of the tree to allow for better flow. You do not need to remove the entire tree. Woody debris in streams, like fallen trees, provides cover and varying water depths for fish, increases dissolved oxygen in the water by creating water turbulence, and establishes food for algae and macroinvertebrates.

Q: What is armoring? Would adding rocks and stones stabilize a streambank?

A: Armoring is a stream restoration technique that involves lining streambanks with rocks, concrete, or other hard materials to prevent erosion. This requires a permit, and you should work with your county conservation district or DEP to get started. Placing rocks in the wrong place or not attaching them appropriately can just make the situation worse. Water has a way of eroding around objects placed in the stream.

Q: Why does the amount of dissolved oxygen in water decrease when the temperature of the water increases?

A: Dissolved oxygen is the gaseous O₂ molecules that are dissolved in water. This is different from the oxygen that is part of the H₂O molecules themselves. Typically, dissolved oxygen enters the water either from contact with the atmosphere or as a byproduct of photosynthesis (plants giving off oxygen underwater).  As water temperature increases, so does the molecular activity, which pushes the oxygen molecules out of the spaces between moving water molecules and back into the atmosphere. The relationship between dissolved gases and water is opposite that of salts and water. Additional information about dissolved oxygen can be found online.

Stream Assessments

Q: How many segments should we break our stream into when assessing its health and condition?

A: This would have to be done on a case-by-case basis depending on how wide and long your stream is as well as how variable the conditions are or how much information you are interested in collecting. You could simply choose a 300 ft. section and assess that same section year after year. If there is a segment of your stream that you are planning on doing a project on, you could assess only that segment. If you are assessing the entire length of stream on your property to prioritize where improvements need to be made, it may be helpful to break this into sections that have distinctly different characteristics.  The main consideration when doing stream assessments is to be consistent from year to year if you want to be able to compare changes over time.

Q: If you have an intermittent stream, what are some of the assessment differences from a larger, more permanent stream? How do you assess streams that dry up in the summer?

A: The general assessment process would remain the same for intermittent streams; however, it may be best to assess your stream in the spring when the water is flowing. Many physical factors, such as embeddedness, vegetation, and riparian zone width, should be the same regardless of whether there is water flowing in the channel or not. Other factors, such as water clarity and in-stream life, will not be able to be assessed when water is not flowing in the stream. The main consideration for doing the stream assessment is to be consistent from year to year, so in this case, the stream should be assessed in the same season so that the data is consistent and comparable from year to year.

Q: Are there any aspects that need to be considered when your stream is flowing on bedrock?

A: The parameters that would likely be the most difficult to assess for a stream flowing on bedrock are embeddedness and macroinvertebrates, depending on the extent of the bedrock. Embeddedness refers to the extent to which rocks (gravel, cobble, and boulders) are covered or sunken into the silt, sand, or mud of the stream bottom, but does not include bedrock. In general, a bedrock substrate will support less life than substrate made up of sand, gravel, cobble, or other loose rocks. If only parts of the stream bottom are made up of bedrock, assessing embeddedness and flipping rocks to look for macroinvertebrates can be done in portions of the stream where this is possible, just remember to be consistent with these actions from year to year. The end of every assessment has a place for notes, where it would be appropriate to add additional information, such as if you were unable to assess embeddedness because the entire stream bottom is made up of bedrock, or if you noticed any sediment deposition in the portions of the stream that you assessed.

 Q: When counting standing dead trees, what is the distance threshold from stream edge to count or not to count?

A: Standing dead trees, or snags, should be counted within the riparian zone.  The width of the riparian zone can be variable, but in general, it extends from the top of the stream bank to where human activities are more prevalent.

Q: How do I know if my stream is part of a wetland?

A: Wetland determinations can be easy or complex depending on the site conditions. There is a process where a professional will visit your site and examine the vegetation and soils to look for wetland plants and coloration in the soil and evidence of wet conditions. When the right signs are discovered, the professional doing the investigation can decide on if it is a wetland or not. Contact your county conservation district to get help getting in touch with the right professionals to do wetland determinations.

Live Staking

Q: I am not sure I understand Live Staking. Why do you plant at the edge of the bank or stream? What time of the year is live staking done? How long do we need to soak live stakes?

A: Live staking is taking cuttings of certain woody species that actively root in wet conditions (like willow) and inserting those sticks into the streambank where they will grow into new plants. Live stakes are planted along streambanks because they require wet soil conditions in order to grow. Here, they will grow roots to help stabilize the stream. Live staking is best done when plants are still dormant over the winter. More information can be found on the Penn State Extension website. Live stakes should be stored after harvesting in a bucket with a few inches of water and planted as soon as possible into the bank (assuming it is the appropriate time of year). The soaking is done to keep them viable between harvesting and planting, up to 2-3 weeks. The stakes should be able to start growing soon after planting.

Q: Is live-staking appropriate for the moist zone, or only the wet zone?  When there is a swift current, should the top of the live stake point upstream or downstream? How deep should you plant live stakes and how high above ground should they be?  At some point, should deer protection or tree guards be used?

A: Live stakes should also grow successfully in the moist zone. Since the bottom of the stake will be 1+ feet into the ground, it should receive enough moisture to begin rooting. It is a good idea to point the live stake at a slightly downstream angle. You want to make sure that at least half or more of the live stake is below ground.  Typically, tree shelters and other types of deer protection are not used on live stakes because they grow quickly and are planted densely to compensate for damage that may occur.

Q: Will live stakes root in gravel bars that have washed up or must they be in the mud banks?

A: Live stakes should be inserted fairly deep into the ground, so depending on the depth of the gravel, there may be more silty sediments a few inches down. The silty soils will provide better conditions for root growth, but the live stakes may also do well in gravel, provided it does not dry out.

Q: Can you live stake with pawpaw? What are some other good species to plant with?

A: According to USDA Plants database, pawpaw do not propagate well from cuttings, so it would not be a good candidate for live staking. Some plants that are recommended are members of the willow family and red-stemmed dogwood species, which are naturally found along stream banks and in wet areas.

Q: Would adding even a tiny amount of rooting powder be useful or totally unnecessary?

A:  Usually, rooting powder or hormones are not needed for live stakes. They should be able to take root and start growing after planting. One of the major benefits of live staking is the low cost and minimal labor needed. Each time you add something more to the process, you take away from that a little.

Plant Selection

Q: What should I plant to avoid vegetation removal from flash floods? Would large roots of dead trees help hold the streambank in place?

A: The best types of vegetation to plant would be ones that are water-resistant and withstand being in a flooded, anoxic environment where the soils may be saturated by water and lack oxygen. These types of plants can survive even when entirely flooded; some examples of these are a river birch, weeping willow, buttonbush, or elderberry.  Look for plants that have a wetland code of OBL (obligated to live in wetland soils) or FAC (facultative, can handle wet or dry soils). Roots can help hold the streambank in place, even if the tree is no longer living, so it is best if they are left in place.

Q: What, if anything, is wrong with using just one type of native grass instead of a seed mix?

A: The challenge with one species is that if it fails, a large area will be plant-free and vulnerable to erosion or being taken over by invasive species. By putting in multiple species, you increase your chances for success and provide more habitat for a wider variety of critters. Having said that, depending on your site, and your willingness to do maintenance; using fewer species is a technique landscapers use when they want to create a more formal look.

Q: What width do you recommend for a buffer? Where do you measure the buffer from, the middle of the stream or banks?

A: There are many benefits to having a riparian buffer, and the recommended width minimum will depend on the desired benefits. Minimums for streambank stabilization, nutrient removal, and sediment removal will be between 35 and 50 feet. If you want to manage for wildlife and have a more robust ecosystem, the buffer will need to be quite a bit wider (100+ feet). A limiting factor might be the size of your property. Typically, you measure a buffer from the edge of the stream.

Q: What are some shade-tolerant and deer-resistant species that you suggest?

A: The publication from our colleagues at University of Maryland Extension lists options for deer-resistant plants, including species such as paw paw, chokeberry, and spicebush. Many of these species will tolerate PA's Hardiness Zones.

Q: If there is non-native vegetation (such as honeysuckle, multiflora rose, knotweed, English ivy, etc.) along the streambank, would you generally recommend leaving it there or killing the invasive and replacing with native shrubs and trees?

A: This is a stream restoration dilemma. In general, it is recommended to remove the invasive species and then plant the area with native species. Control of many invasive species can be a multi-year effort but planting the site with desirable vegetation after removing the invasive is a crucial first step to prevent those unwanted species from recolonizing. If necessary, erosion control fabric and/or toe stabilization at the streambank shoreline interface can be used to provide greater stabilization. So, the short answer is, yes, remove the invasive plants, but be ready to protect your site from runoff and have your replacement native vegetation ready to install right after. Just don't remove more than you can restore and are prepared to manage.

Grading

Q: Does removing undercut banks via grading reduce available trout habitat/escape cover? What are additional options? Seems like grading addresses erosion but not necessarily habitat concerns.

A: If you know that your undercut banks are used for trout habitat, you can plant live stakes to try and secure the above and side banks around this habitat cover. This may not prevent the bank from collapsing in the future, but it does maintain your trout habitat. You are correct, grading is always the best solution for severely eroded banks. Keep in mind that overhanging vegetation is also considered a habitat enhancement and is another way to provide cover for fish.

Q: Explain the 3:1 ratio, please. Is it rise over run or run over rise?

A: The 3:1 ratio is width to depth ratio (run:rise) and is when vertical banks are pulled back from the stream into the floodplain, at distance approximately 3 times the height of the existing banks. Over time, this will allow banks to restabilize naturally.

Q: Wouldn’t it be good to have silt fencing handy or already installed to reduce the chance of erosion or loss of more soil while the project is under construction?

A: The necessary erosion and sediment controls are something that would be determined as the permitting process takes place, but yes, it would be a good idea to have any controls prior to construction starting. When grading the banks themselves, it is hard to implement effective sediment barriers because you are generally moving soil right in the stream itself. Most of these control practices are meant for upland disturbances and keeping the soil from traveling to the stream.

Q: In wooded areas, is grading not an option since it will hurt the existing tree roots?

A: Very true. Healthy trees can tolerate some root pruning, but it is important not to remove too many roots (same idea as with branch pruning) to avoid overstressing the plant. The key is to minimize if you can; however, if it's an invasive tree, then you may want to remove it and replace it with a native species anyway.  Additionally, in some cases, it might be worth taking down a few mature trees to allow for grading and then replant with young trees.

Permitting

Q: Would you need a permit for using rock and soil fill as well as straw cover during live staking? Would you need a permit for using seed and matting during live staking?

A: While live staking and seeding onto already bare areas does not require a permit, adding rock and soil to a stream bank most likely would require a general permit. Contact your county conservation district prior to adding fill to a streambank. If all you are doing is planting or using biodegradable matting, and you are not manipulating the shape of your bank or the channel itself, you usually do not need a permit.

Q: Can I build up the bank on my side of the stream if the other side belongs to my neighbor? If I do build up the stream bank, are their federal rules pertaining to streambank erosion mitigation, or is it all state regulated?

A: If it is on your property, yes, you can work on that side of the stream. But, if you are doing any kind of earth moving even on your own property, a permit will be required. Check with your county conservation district first to see what's needed. When you extend beyond a certain size project, it becomes the jurisdiction of the Army Corps of Engineers. Your county conservation district or regional DEP office can help you figure out if your project requires that federal permitting as well.

Q: If you get a permit to grade the stream bank, generally how long is the permit good for in terms of doing ongoing maintenance as needed to maintain the stream bank in the same condition?

A: Certain parts of a permit, such as a Pennsylvania Natural Diversity Inventory (PNDI), may only be valid for a couple of years. You should discuss the permit period with the permitting agency, such as the county conservation district or Department of Environmental Protection (DEP). Ongoing maintenance is something that should be included in the permit application. You’ll need to achieve permanent stabilization and schedule a final inspection to officially close your permit. Discuss all permitting questions with your county conservation district or the DEP prior to beginning any grading.

Q: What can you do to stop active downcutting from advancing (without and with a permit)?

A: The only stabilization work that can be done in and around streams without a permit includes adding plants, whether that be seeds, live stakes, or seedlings. If debris is causing erosion, this can also be removed without a permit, as long as heavy equipment is not needed. Oftentimes, grade control structures made out of large logs and rocks are used to prevent downcutting; however, adding these materials to the stream should be done according to qualified designs and would require a permit.  Contact your county conservation district to discuss adding grade control structures prior to starting any work.

Q: Is drainage area a consideration in permitting?

A: Yes, the size of the drainage area leading to your stream is often a consideration in permitting and may affect which permit is needed.

Q: How long does it take to get a DEP permit?

A: It can vary from a few weeks to a few months, depending on how many current applications are being reviewed in your area. Plan on a few months and contact your regional DEP office or county conservation district to check on what they think their current timeline is.

Q: Will the DEP allow for a GP3 permit after the fact or post construction? 

A: The DEP does not allow GP3 permits to be filed post construction and requires that work does not begin until the following steps are completed (from the DEP’s website):

1. You have received an acknowledgment from the Permitting and Technical Services Section or County Conservation District that your General Permit Registration form has been received and registered.
2. Your Erosion and Sediment Control Plan has been reviewed and determined to be satisfactory by the County Conservation District.
3. You have notified the Pennsylvania Fish and Boat Commission and the County Conservation District 10 days prior to the start of construction (See Part Two, Section D of above link).
4. You have obtained any other Federal, State or local permits which may be required, including written authorization from the U.S. Army Corps of Engineers for gravel bar removal.
5. You have complied with any other applicable preconstruction requirements as listed in Part Two, Section E of above link.
6. You have provided written notifications to the municipalities and county where the projects are located prior to the start of construction.

Q: How much do permits associated with stream projects cost?

A: Costs associated with permits can often be looked up on your county conservation district website.

Q: Do man-made waterways, such as canals, fall under the same permitting requirements as naturally formed streams and rivers?

A: Yes, 25 Pa. Code Chapter 105 (Dam Safety and Waterway Management) regulates both natural and artificial bodies of water.  Activities like grading, digging, or placing fill in a regulated area would be considered an encroachment or obstruction and would require obtaining a written permit before beginning any work. It is always best to err on the side of caution and contact your regional DEP office for specific guidance on unusual situations like these.