Post by Admin on Aug 10, 2017 9:22:22 GMT -7
New Road Ditches Get Tested in Severe Downpour...
New Culverts Are Needed
New Culverts Are Needed
A sudden thunderstorm that slowly moved over High South Glastonbury in the early evening of August 9th, 2017 tested the newly dug ditches alongside Hercules Road. The freshly graveled and compacted surface of Hercules shed the rain well and it flowed into the fresh ditches. The road was soft after shedding most of the rain and absorbing some. Surface and sub-surface water flowed to the lowest point, the ditches, and was channeled along the edge of the Hercules towards Dry Creek Road.
Unfortunately once the water hit Dry Creek Road it flowed over the intersection and started to rapidly erode both roads. A large sheet of water formed and quickly dug into the roads. Rushing water carried away the clay binder that normally holds the road mix gravel together. If there was a large diameter culvert placed under Hercules and parallel to Dry Creek the water flowing in the new ditches along Hercules would have been able to travel under the intersection and in to Dry Creek ditches. The lack of a culvert caused some of the freshly laid gravel to be washed away.
A similar problem occurs when driveways and private roads that lack culverts intersect with Glastonbury platted roads. The platted road usually experiences erosion as a result and landowner assessment funds are washed away. Per GLA Road Standards individual landowners are responsible for installing culverts under their driveways and private roads whenever they intersect with a GLA platted road. Additionally the driveway or private road must be level with the platted road for at least 100 feet, if possible, so they do not dump rushing water onto a platted road.
A similar problem occurs when driveways and private roads that lack culverts intersect with Glastonbury platted roads. The platted road usually experiences erosion as a result and landowner assessment funds are washed away. Per GLA Road Standards individual landowners are responsible for installing culverts under their driveways and private roads whenever they intersect with a GLA platted road. Additionally the driveway or private road must be level with the platted road for at least 100 feet, if possible, so they do not dump rushing water onto a platted road.
Further up Hercules Road the ditches also did their job. This section of road received gravel in 2016 and 2017. The rain flowed into the ditches and is channeled down the side of Hercules.The gravel is intact and the clay binder was not eroded. Once this road dries, it will be fine for heavy traffic.
Chemically speaking, the rain dissolves calcium carbonate in the clay binder. When the road dries the calcium carbonate forms a strong bond with any dirt, sand and gravel it is in contact with. If you picked up the wet road gravel mix just after a rain it would clump like moist clay. When it dries under a hot Montana sun it hardens into something like weak concrete. Adobe follows the same pattern and is often used for building construction in the south-western US.
Chemically speaking, the rain dissolves calcium carbonate in the clay binder. When the road dries the calcium carbonate forms a strong bond with any dirt, sand and gravel it is in contact with. If you picked up the wet road gravel mix just after a rain it would clump like moist clay. When it dries under a hot Montana sun it hardens into something like weak concrete. Adobe follows the same pattern and is often used for building construction in the south-western US.
Summer thunderstorms and sudden downpours provide an excellent way to test road designs in Glastonbury. Our soil has a high clay content and does not rapidly absorb water. Runoff is more common and our roads must be able to accommodate a rapid influx of water. Culverts are essential. Unfortunately they are sorely lacking in Glastonbury and often poorly maintained. Serious flooding occurred at the intersection of Hercules Road and Polaris Way on August 9th. The roads were freshly graveled, graded and compacted just two days ago. The area of deepest water across Hercules is a spot where potholes form every year.
A culvert placed under Hercules would channel the rain water under the road and reduce the chances of potholes forming. Better ditches on both sides of the road would allow rain water to flow into Golemeyer Creek which is only a few hundred feet down the road. Rain water was also building deep puddles and causing fresh erosion on the far side of Polaris. A culvert placed under Polaris and parallel to Hercules would solve that drainage problem.
Culverts across platted roads are a major project and expensive. Electrical lines must be located and dealt with. The road surface must be rebuilt. GLA funds are limited but this and many more projects must be put on a waiting list and reviewed by a professional road engineer.
Culverts across platted roads are a major project and expensive. Electrical lines must be located and dealt with. The road surface must be rebuilt. GLA funds are limited but this and many more projects must be put on a waiting list and reviewed by a professional road engineer.
