Determining the level of groundwater is a mandatory study in densely populated areas near water bodies, rivers, lakes, seas. Any person acquiring a land plot for the construction of a residential building or commercial buildings should be aware of the depth of groundwater on the site. The method of building the foundation, the choice of materials, the amount of costs and even human life depend on this.
What are water tables?
Before you determine the water levels, you should know what it is. Groundwater is the first aquiferous underground layer that is above the clay soil (it prevents water from seeping out, retains it). Groundwater has a source. As a rule, these are nearby water bodies, as well as precipitation, melted snow. The rise in the water level is directly dependent on the time of year, the power of soil resources, that is, their volume. These factors contribute to a change in the depth and distance to the ground water surface. In the spring, their level rises due tosnowmelt, heavy rains, abundant moisture from other sources. In summer it drops, and the lowest water level is recorded in winter.
Water level detection method
In order to correctly determine the water level on the site, the help of surveyors will be required, but this procedure can be performed independently. Previously, it was determined by digging wells. Today there are several methods available. The first is the most modern. Tools will help to use it: a garden drill (its length should be at least two meters), a long metal rod (marks should be made on it that indicate centimeters).
Drill one hole for the entire length of the drill and do not touch it for a day. In twenty-four hours, water should appear in the well. Then lower the rod into the hole, which will serve as a measure. The mark will show the depth of the liquid. If the rod became wet at the level of ten centimeters and below, then, knowing the depth of the well, it is possible to calculate the distance of groundwater. For example, subtract ten from two hundred centimeters (measuring with a rod). The final number is the distance to groundwater. The fluid level should be checked over the next few days. If the result does not change, it will be considered a ground mirror. If the depth is more than two meters, use a spoon drill. Experts advise to determine the level of soil water in the spring.
Folk methods
ForDetermining the water level used to use the method of observing the vegetation that prevails in a certain area. If the soil is moist, then meadowsweet, alder, forest reed, willow, currant, meadowsweet, elm, sorrel grow on the site. These plants indicate excessive soil moisture and high occurrence. Pay attention to the slope of the bushes and trees. If the crowns lean to one side, then there is a high soil layer nearby. The peculiarity is that the grass and vegetation in such an area is abundant, has a juicy green color.
What is it for
Determining water levels before laying the foundation is an important step in any construction. If the groundwater level is high, this means increased soil moisture, which has low bearing capacity. Objectively, it is impossible to build a house on such a site. If water levels are high, it can fill dug pits and trenches. In this case, it is not recommended to build a foundation: first, excess water should be pumped out and waterproofing should be done. But such measures are considered temporary, since the high level of groundwater causes flooding. If the house is built without taking these factors into account, then there will always be water in the basement, and mold and fungus will appear in the house itself. In addition, high levels in settlements cause spring floods and floods. For example, water levels in Veliky Ustyug are often elevated, which is why the threat of flooding in this area is always present.
Depth
High levelswaters are considered if they lie two meters or less. Such levels are typical for wetlands, lowland slopes, riverbanks, lakes. A low level of occurrence is considered to be groundwater at a depth of more than two meters. This is a normal level of occurrence for building a house. The depth of water flow means the upper underground layer, the formation of which is facilitated by annual precipitation, rivers and lakes located nearby. Not only the construction of residential buildings depends on the depth of groundwater, but also the organization of the landscape, planting plants and trees. If the site is located in a high-lying area, you should take care of full drainage. Before construction, laying the foundation, conduct a depth survey.
Floods in Veliky Ustyug
High water levels and, as a result, threatening floods, floods have plagued the city of Veliky Ustyug in the Vologda region since the sixteenth century. It was then that the Great Ustyug Chronicle first mentioned the destruction caused by water.
The most famous flood occurred in 1998. High water levels in Veliky Ustyug led to catastrophic consequences. In the spring, a sharp rise in the water level began in the Sukhona River, which was facilitated by an intense ice drift, which led to traffic jams. Then the city of Veliky Ustyug and twenty-four other settlements became the flood zone.
In the spring of 2016, more than 1,500 houses were flooded in the Vologda Oblast. The water level in the river rose by 50centimeters.
Twenty-one emergencies related to rising water levels were recorded in Veliky Ustyug in the 20th century.
