 An important consideration of new road construction is the removal of water. Ditches along the side of the road permit surface and underground water to collect and drain away from the road bed or intercept water from the surrounding area and carry it away. Over a period of time, these ditches may collect large amounts of silt or debris and may become overgrown with heavy vegetation. This interferes with the proper flow of water in the ditches and the culverts and drains that connect them. Water that does not drain away properly will soak the base material of the road bed causing serious maintenance problems such as potholes, cracking, settling or depressions, or complete surface failure. A well-maintained ditch will prevent road failure and help keep the roads in good condition. This videotape will focus on the procedures involved in the mechanical cleaning of unlined ditches. But before we see the cleaning procedures, we will review the structure of a ditch and how it functions to protect a road and the adjacent property. Using this ditch as our example, we can look at four parts of any ditch. They are the road shoulder, the ditch in slope, the ditch back slope, and the ditch flow line. The road shoulder is the surface area beside the traffic lanes. The rain that falls onto the roadway surface runs down the shoulders. The ditch in slope provides the incline that keeps water moving away from the roadway shoulder. The ditch back slope is the opposite side of the in slope, that is the side furthest away from the roadway. The back slope provides the incline, directing water from adjacent land to the bottom of the ditch. The bottom of the ditch is the ditch flow line. This flow line allows water deposited in the ditch to flow smoothly along the ditch to outlets and drains water away from the roadway. Now that we have defined the different parts of an unlined ditch and discussed their functions, we can explain the procedures for cleaning them mechanically. Mechanical ditch cleaning can be done with a machine shovel or a motor grater. The type of equipment used depends on the condition of the ditch and the availability of equipment. First, we can look at the conditions appropriate for motor grater ditch cleaning. To use the motor grater ditch cleaning procedures, the ground needs to be solid enough to support heavy equipment. The ditch in slope and back slope need to be gradual enough to allow the motor grater easy access, and the ditches should be long and not interrupted frequently by drain pipes or culverts. Ditch cleaning with the motor grater involves eight steps. We will describe them in detail. These steps are planning the job, setting up traffic control devices, cleaning the ditch, cleaning adjacent culvert inlets and outlets, and outfall ditches, properly disposing of unwanted material, cleanup of the job site, inspecting the finished job, and finally removing equipment from the job site. Now we can look at each of the steps one at a time. Step one is planning the job. This should be done well in advance to make sure that when equipment and men arrive at the job site, the ditch can be cleaned correctly and efficiently. First, you need to make a thorough visual inspection of the site. As you inspect the site, check to see that the ground is firm enough to support heavy equipment as demonstrated here. Determine what the grade of the end slope and back slope should be, and check to see where any culverts, pipes, or outfall ditches are located. In making these decisions, it is important to consider the types and capability of your equipment. Cleaning procedures may vary according to these capabilities. The next decision in planning is to determine what to do with the waste material that will be cleaned out of the ditch. There are two ways to dispose of this material. The waste material can be spread out on the adjacent right-of-way beyond the back slope, or it can be brought out to the road or road shoulder for pickup and disposal. Here it has been determined that it will be necessary to remove the material for disposal. Once a determination has been made, crew and equipment can be arranged for and brought to the job site. There is more to planning than inspecting a job site. An additional part of the planning process is to explain to the crew what each of their jobs are. This involves discussing the job with the equipment operators and other workers so that everyone understands the procedures that will be followed. Let us move on to step two. Step two is setting up the appropriate traffic control devices on the road to alert traffic to the work area. The videotaped traffic control during maintenance operations gives a detailed explanation of these procedures. In any case, be sure to follow your agency's work area safety guidelines. The signs and markers alert drivers that road maintenance is being performed, and they help prevent traffic from interfering with the job. Next is step three. This involves the actual cleaning of the ditch. The motor grater will take a preliminary pass to clear vegetation before the in-slope cut can be made. Here this vegetation is being moved up onto the road surface. Now the motor grater blade should be positioned so that its edge touches the bottom of the ditch at the flow line. As the motor grater moves forward, the blade cuts along the flow line to remove mud, silt and other material that is collected at the bottom of the ditch. Notice that the material rolls smoothly up off the blade, away from the flow line, and forms a windrow on the shoulder. The motor grater continues to follow the flow line of the ditch. Notice that the blade restores a smooth flow line on the in-slope and makes the ditch bottom uniform so that water can flow properly along the ditch. As you can see here, the windrow has been moved from the bottom of the ditch onto the shoulder. The motor grater returns to the shoulder and backs up to the starting point to continue moving the windrow onto the road surface. Notice that the blade has been set so that it can move the material onto the road without cutting the road or shoulder surface. The next procedure in this job involves cleaning the back slope of the ditch. In this case, the motor grater is positioned over the in-slope with the opposite edge of the blade now touching the ditch bottom. The cut that is made along this edge of the ditch redefines the ditch shape on the back slope side and clearly establishes the flow line at the bottom. After cutting the back slope, the windrow will be moved up the in-slope, shoulder, and then onto the road as before. Watch as the operator performs this part of the procedure. This pass moves the windrow taken from the back slope and ditch bottom up off of the ditch in-slope onto the shoulder. The material from the back slope is now brought from the shoulder onto the roadway and added to the windrow previously formed during the cleaning of the in-slope. As the grater finishes this section, we can begin step four. Step four is cleaning outfall ditches, culvert inlets, or drain pipes. These areas usually need to be cleaned by hand since access to them is difficult with large heavy equipment. This may involve cutting down heavy vegetation and plant growth and then shoveling the build-up of silt, leaves, and other debris away from the ditch. Collected material may be placed with the other material for removal or it may be spread out beyond the back slope if appropriate. If placed beyond the back slope, make sure the material will not wash back into the ditch. Be sure to clear outfall ditches that connect to the main ditch. The water in the main ditch is diverted into these ditches and drained further away from the roadway surface. This function is critical in providing good roadway drainage. In this case, the outfall ditch provides drainage away from the bridge. Clean outfall ditches as necessary to ensure they are clean and open. In some locations, there also may be culverts or pipes that drain water from the ditch. To clear all pipe openings sufficiently, care should be taken to maintain the proper contour and shape of the ditch at culvert inlets and outlets, and to maintain the proper flow path. For additional explanation on cleaning of these areas, refer to the videotape titled Cleaning of Lined Ditches, Culverts, and Catch Basins. At this point, we have collected all the material from the ditch and inlets and outlets in a windrow on the road surface. Step 5 now is to remove the material from the roadway. Traffic control procedures for this part of the job are important. They permit efficient loading and minimize interference from traffic. Again, always follow your agency's safety procedures. This procedure is an efficient loading method. It minimizes cumbersome maneuvering of the heavy equipment, as well as the amount of time the truck is out on the road. Once the truck is loaded, the material that was collected from the ditch is taken to an approved location for disposal. This location should be well away from the road to prevent any debris from washing back onto the road or into a ditch. The next step, step 6, involves cleaning the job site. Again, traffic control procedures should be used to ensure the safety of the public and the road maintenance crew. Be sure the work site is clean. This is especially important when the material removed from the ditch is placed on the road during the job, as was done here. Small rocks, gravel, or other debris left on the road could cause a safety hazard to traffic if not removed. Here, sweeping of the road is being done mechanically. This type of cleanup may also be done by hand. The important thing is to clear the road of unwanted material. Once the job site is clean, you are ready for step 7. This is an inspection of the ditch. Be sure that the flow line is uniform with no high or low spots. Also check that the ditch contour is correct, that the slopes are smooth, and that the outfall ditches, culverts, and pipes are clear and unobstructed. Keep in mind that the cleaned ditch should be able to handle the flow of water down the slopes. Provide a proper flow path along the ditch bottom and permit smooth flow through outlet structures. After you have determined that the ditch is properly cleaned, you have one final job responsibility, step 8. It involves removing traffic control devices and equipment from the site. First, remove the traffic control devices used during the maintenance procedure. During this time, care should be taken to continue traffic control. Once all safety devices and equipment have been cleared from the roadway, you and your crew can move on to the next job site. That concludes the detailed explanation of the eight steps for machine ditch cleaning with a motor grater. Now we will review each of these steps briefly. These steps are 1. Planning the job. 2. Setting up traffic control devices. 3. Cleaning the ditch. 4. Cleaning outfall ditches, culverts, and drain pipes. 5. Properly disposing of unwanted material. 6. Cleaning of the job site. 7. Inspecting the finished job. And 8. Removing equipment from the job site. Now is a good time to stop the videotape and discuss the procedures for cleaning online ditches. In the next segment, we will see another application of these procedures. Here is another ditch that requires cleaning. Even though this ditch is designed differently, the same eight steps can be followed for cleaning online ditches. Follow along as our supervisor uses these eight steps. Step one involves planning the job. First, you need to give a visual inspection of the site. Remember, this inspection will determine the correct type of equipment needed and the proper cleaning procedures. This ditch has conditions that are appropriate for machine shovel ditch cleaning. There are several factors that go into making this decision. We can look at them one at a time. Shovel ditch cleaning should be used if any of the following conditions are apparent on the job site. If there is excessive water causing the slopes to be too soft to support heavy equipment, or when the in-slope and back-slope are too steep for easy access, or when the ditches are frequently interrupted by drain pipes or culverts. Two of these conditions are apparent in this ditch. Next, plan the proper method of disposal of unwanted material after its removal from the ditch. Depending on the job condition, the waste material can be deposited beyond the back-slope, or as in our case, be loaded directly onto trucks for disposal. Step two involves setting up appropriate traffic control devices on the roadway to alert traffic of the work area. Step three involves the actual cleaning of the ditch. Note that the excavator is on firm ground and reaches down into the ditch to remove the unwanted material. Then it loads the material directly onto the truck for disposal at a designated dumping area. During cleaning, the excavator operator needs to take care in re-establishing the ditch flow line so water will flow smoothly down the cleaned ditch and through the rest of the drainage system. Step four will be hand cleaning of inlets and outlets. Make sure that correct ditch contour and shape at the pipe inlet and outlet maintain the proper flow path as explained in the earlier part of this videotape. Now we can begin step five. This is the procedure for disposal of waste material. Here waste material should be hauled well away from the ditch location. This prevents any debris from washing back onto the road or into the cleaned ditch. Once the waste material has been removed, step six follows. This is generally cleaning the job site. Clean the roadway and shoulders of unwanted material which could cause a safety hazard to traffic if not removed. Now step seven, inspect the finished ditch. Check the ditch contour and flow line to make sure there are no high or low spots. The last step, step eight, is to remove any remaining traffic control devices and equipment from the site. This concludes the procedures used when ditch cleaning is performed using either a motor grater or a machine shovel. If properly followed, these procedures will result in a clean well-maintained ditch, an essential part of a well-maintained road.