 Water control is one of the most important considerations in planning your next stream-smart road crossing project. Without adequate water controls, excavation becomes very difficult, sediment can end up in the stream, violations can then occur, project costs can go up and your schedule can be thrown off, not implementing the project successfully. In this video, we'll share some issues that are important to keep in mind and avoid in your next stream-smart road crossing project. The first piece is timing. In-water work here in Maine typically is required to occur between July 15th and September 30th, and that's the driest time of the year in the middle of summer. This is when streams and rivers are at their lowest, so there's less water to manage and reroute and control, making the project run more smoothly and effectively. In preparing your schedule, it's also important to make sure you have all of your permits in hand before construction starts. Consulting early and often with your local natural resource agency will help make sure you get your permits on time. Coordinating early and often with natural resource agencies to make sure you're accounting for any state or federally-listed species that may be present in your work zone. This helps you plan and make sure you're accounting for the mitigation measures that you will have to implement in order to meet the compliance that's required. In preparing to mobilize your equipment, the first step will typically be to remove the fish that are within the work zone. Coordinating with local natural resource agencies to have qualified biologists on-site to implement this work is key. They'll first install block nets above and below the work site so that once fish are removed, they cannot swim back into the work zone. Typically, the biologist will electrophish the entire reach to capture those fish and then relocate them into appropriate habitat. This is also a great opportunity to see what fish are in the stream that will benefit from your Roadstream Crossing project. In addition to having the water controlled within the stream so that your work area is dry, you need to also make sure that the erosion controls on-site are in place and functional. Silt fences and hay bells are some examples of best management practices that make sure that sediment that's moving around on-site do not make it into the stream or the river or the adjacent wetlands. In planning the equipment needed to have on-site, it's very important to make sure the pumps are adequately sized given the stream or river that you're working within. These pumps are important to move the clean and dirty water in and out of the work area so that the equipment can move efficiently and effectively and the project can stay on schedule. Not having appropriately sized pumps or enough fuel on-site or having someone not pay attention to these water control measures will easily result in project delays, especially when an unexpected rainstorm sweeps through. This can result in violations, it can result in higher project costs, and then it could result in a project not getting done on time. Let's talk a little bit more about the details of water control in the process of constructing a StreamSmart crossing. A StreamSmart construction project definitely demands good water control, and that water control happens in two different ways, and there are quite a few details too I'd like to discuss with you. We need to control stream flow, so even in a summer time like this with low stream flow, we have water to deal with. With fish and other organisms we've talked about controlling and removing from the work site, we need to allow that flow to continue somehow through or around the work site. And we also are going to be generating some dirty water in the process of construction. We want to keep the site as dry as possible to make excavation as simple as possible, and then we need to remove that dirty water from the work site. So depending on the type of crossing we're building, either a closed bottom crossing where we excavate the entire site, or an open bottom crossing where we often are digging simply two trenches, one on either side of the center of the crossing in the stream. We need to do these things differently, but we still need to control the water. The simplest approach we like to use in handling the flow of the stream through or around the site is to simply leave the existing culvert in place to carry the water right through the middle of the site and dig on either side of it for our footings and abutments to put in a new stream smart crossing. Sometimes that doesn't work because the current crossing is simply not competent enough, it's rotting and falling apart and it just can't carry the flow. In other times it's not long enough or it's at the wrong angle and so we need to use a different approach. Sometimes in those cases we can simply remove the old culvert while we pump water around and add a temporary plastic pipe that's at the right length and the right elevation to carry the water right through the site. If we're going to build a big closed bottom structure like this one, we need to excavate the entire site and that means running the water all the way around the site either with a bypass pipe or a bypass channel or the simplest method that we often use that does take a little bit more maintenance and work and energy is to pump around the site. When we have our upstream cofferdam in place to back up water there, we pick up the water from there and we pump it around the site with a series of hoses to distribute the water back down to the downstream area below the downstream cofferdam keeping the work zone free of any incursions of stream flow. This ensures that the fish living in the upstream area and the downstream area are able to continue their living in the stream while we do our work. It's really important when using pumps to divert stream flow to be sure you have screening on the pump intake so you're not sucking fish up into your pumps and it's also really important to think about how far that water has to go to be sure you have enough hoses and know where those hoses are going to run to be sure that you're passing the water effectively and not interrupting the construction zone unneededly. It's also really important to have somebody assigned to manage that whole system of pumps and hoses and fuel it takes to keep them going to keep from getting fuel in the stream and in wetlands but also to be sure the system works and continues to work throughout the process of construction. The other aspect of water control is handling the dirty water that gets generated. Once we've blocked off the clean stream flow and are pumping it around or bypassing the work site we're going to be generating some dirty water and we need to manage it. There are several ways to filter it in the nearby forest with a couple of different methods. One way, the simplest way, is to simply pump that water out of the work zone into the nearby forest and diffuse the flow at the outlet of the hose or pipe with some filter fabric so that there is no exposed soil. The forest floor is not eroded but that water can simply seep into the forest floor and eventually make its way either perhaps across the surface of the forest floor or through the ground water back into the stream. Sometimes when you have a lot more water to handle it's really important to have a series of filter basins. The simplest form are composed of hay bales and filter fabric where the water can flow from one into the other and the other to be able to filter out any fine sediment that is suspended in that dirty water before any of the water makes its way back to the downstream area. Another approach we use often is to use a filter bag where the outlet hose of the dirty water pump is flowing into a filter bag that does that filtration itself. The water then oozes and sort of seeps out of that filter bag into the forest floor and eventually back down into the downstream area. Several of the common problems we see in controlling water at our sites relates to the size of the crossing. On a lot of smaller crossings, let's say six feet wide to even up to twenty feet wide, we don't generate a lot of dirty water so often just a little two inch pump can do. It's really important to look at the weather and to do some calculations about how much water you're really able to move around your work site with whatever pumps you've chosen. Make sure you have extra capacity, make sure you have pumps on standby in case you need them and plenty of extra hoses to be able to reach where you need to go. And often we've had hoses with holes in them leaking dirty water in places it shouldn't be. The best way we've found to solve that problem is to run a pipe under the roadway where the work is going on. Excavators and dump trucks are going back and forth and the dirty water hoses and for that matter the clean water hoses can be rooted through those pipes to keep from being damaged and to keep from limiting the construction activity to make it a little bit more efficient. There are plenty of sites where at the outlet of the stream crossing, before we built this big beautiful new crossing and there's an existing pipe, we'll dig a sump hole where we want all the dirty water to come down into and that dirty water hole can sometimes be full of fine woody debris that can tend to really clog up our pump intakes. The best solution for that is to dig that sump hole quite large and fill it with three-quarter inch clean crushed stone and have your pump intake embedded in the middle of it and that way the surface of the crushed stone can act as a filter to hold out the dirty woody debris from clogging up the intake of the pump and hopefully provide enough water flow through the stone to evacuate that dirty water out to where you need it to go. When we're finished with our site, we've built a beautiful new crossing, we've built our stream bed and banks inside, we need to remove our water control and water diversion approaches and mechanisms which is the upstream cofferdam and a downstream cofferdam and all the hoses that were involved in that. And so that takes a little bit of time and planning and should be done carefully. What we usually do is slowly release the upstream flow from the upstream cofferdam and keep pumping all the dirty water that that sometimes generates out into the area where we're filtering the dirty water. We do that slowly in a controlled way so that we can manage that dirty water flow and eventually as the water clears up we can release the cofferdam entirely and allow the stream to flow naturally as we would want it to be after we're absolutely finished with our stream crossing construction. By having a good plan for water control and moving through it very carefully, being sure you have backup plans for big summer storms that do sometimes come during our construction projects, by attending to these details, keeping people on staff knowledgeable and responsible for controlling the water. These projects can go very, very smoothly and efficiently and costs can be kept within budget and problems can be avoided. When we're finished with our StreamSmart crossing, we always remember our key goal. We know that we want habitats to be connected for aquatic critters and for terrestrial animals. We know we want to protect the roadway against the threat of future storms and large flood events. We know that we're accomplishing our goal when we build a StreamSmart crossing according to our design. We want the stream to be able to act like a stream.