 For the maintenance division, public enemy number one is water. There just seems to be no end to the road damage water can cause. To base failure and everything in between, small cracks will either get larger or spread out and eventually become potholes. So it doesn't take long to realize that we have to control where the water goes or as the foreman's handbook says, we have to maintain drainage. Although drainage problems can occur just about any time, our major emphasis is in the spring and the fall. In the spring we have to make sure that all the drainage features can handle the tremendous amount of runoff from the mountains and in the fall we have to be sure that melting snow from our constant freeze-thaw cycle will be able to drain away from the road. Normally drainage maintenance can be handled by a one or two man crew and very little equipment but there are always exceptions. Severe cases call for either more people or heavy equipment such as the specialized piece used to clear obstructed culverts or for widening or clearing a blocked drainage channel. So the first thing to keep in mind is to discuss the situation with your supervisor so that you have whatever it takes to restore proper drainage. With that introduction then let's look at some typical drainage problems you are likely to encounter. As with any other activity your first concern is with traffic control. So set up all the devices necessary to do the job safely before doing anything else. Next look over the culvert or drainage channel or both and determine first the cause of the problem. The most common situations you'll find are overgrowth in the channel and buildups of silt in the culvert itself. You should also examine both the inlet and outlet ends to find what caused the obstruction. In most cases the majority of your work will be at the inlet end because silt and debris carried by the water tend to block the entrance of the culvert but again there are always exceptions. As you can see here the outlet is where the obstruction is. Along with checking the culverts, channels, inlets and outlets you should also examine the condition of the drainage feature. A bent pipe like this has to be repaired if it's ever to function properly and concrete culverts have to be checked for spalling. Inform your supervisor when you find spalling so the condition can be repaired before it deteriorates any further. Now the corrective action. As I said earlier you'll normally find it necessary to clear or widen the channel at the inlet end. Your two biggest concerns here are that you re-establish the original flow line and that you maintain the pleasing appearance of the roadside. When you begin excavation it's always a good idea to have someone directing you. That way you can get as close to the culvert as possible but without the risk of damaging it. So be careful not to excavate any more material than necessary. If the excavation is too deep water will flow under the culvert rather than through it. The same holds for the width of the excavation. The channel should be only about as wide as the culvert at the inlet end. If you make the channel too wide water will actually flow alongside the pipe instead of through it. And of course in both cases the water will undermine the foundation of the roadway. Culverts that are blocked with silt have to be flushed out but keep in mind that that's only part of the corrective action. The main cause of the silt buildup is an improper flow line. So be sure to excavate the channel along with flushing the culvert. If the silt buildup is relatively minor clearing with a water jet will normally work fine but if there is a lot of silt or if the silt has hardened you'll probably need to use a snake along with water pressure. As you can see here there's a tremendous amount of water pressure so always stand clear of the snake when you turn the water on and be sure to feed and extend the snake slowly. As I said before discuss the situation with your supervisor and get the equipment you need. Okay we've looked at channels and culverts but you should also be aware that drop inlets and catch basins need to be maintained periodically as well. Although these drainage features are small they're every bit as important as the larger culverts and when water can't pass through they can cause every bit as much trouble. Of course no matter how well we do our jobs there will be times when there's just more water than the drainage system was ever designed to handle. In extreme cases like these you'll be called on to remove broken tree limbs and other debris as well as providing slope protection for overflowing channels. Now as I said in the beginning of the program drainage problems can develop at any time and it's water that causes most of the damage to our roadways. So keep that in mind on every job. If you're repairing an edge rut problem try to find out what caused it. If you're sealing cracks check the surrounding drainage features of the surrounding channels and culverts clear. And whenever you see water ponding along the road stop and investigate. Maintaining drainage is the most important preventive maintenance activity we perform and the sooner we spot and correct improper drainage the less damage will result and the longer our roadways will last.