Groundwater level determination 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 utility 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 groundwater levels?
Before determining water levels, you should know what it is. Groundwater - this is the first aquifer underground layer, which is located above clay soil (it prevents water from seeping, delays it). Groundwater has a source. As a rule, these are nearby water bodies, as well as precipitation, melted snow. The rise in water level is directly dependent on the time of year, the capacity of soil resources, that is, their volume. These factors contribute to the change in the depth and distance to the surface of the groundwater table. In the spring, their level rises due to the melting of snows, heavy rains, and plentiful moisture from other sources. In summer, it drops, and the lowest water level is recorded in the winter.
The method of determining the water level
In order to correctly determine the water level on a 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 available methods. The first is the most modern. Tools will help to take advantage of it: a garden drill (its length should be at least two meters), a metal long rod (marks should be made on it that indicate centimeters).
Drill one well for the entire length of the drill and do not touch it during the 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 fluid. If the rod became wet at a mark of ten centimeters and below, then, knowing the depth of the well, you can calculate the distance of occurrence of groundwater. For example, subtract ten from two hundred centimeters (measuring with a rod). The final number is the distance to the groundwater. Check the fluid level during the following days. If the result does not change, it will be considered a soil 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
To determine the water level, the method of monitoring vegetation, which prevails in a certain area, was used earlier. If the soil is moist, then meadowsweet, alder, forest cane, willow, currant, meadowsweet, sorrel grow on the site. These plants indicate excessive soil moisture and high occurrence. Pay attention to the slope of shrubs and trees. If the crowns leaned in one direction, it means that there is a high soil layer nearby. The peculiarity is that the grass and vegetation in this area is plentiful, has a juicy green color.
What is it for
Determining the water levels before laying the foundation is an important stage in any construction. If the groundwater level is high - this means increased soil moisture, which has low bearing capacity. Objectively, you can’t build a house on such a site. If water levels are high, it can fill dug pits and trenches. In this case, building a foundation is not recommended: first, pump out excess water and make waterproofing. But such measures are considered temporary, since a high level of groundwater causes flooding. If the house was 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 elevations in settlements cause spring floods and floods. For example, water levels in Veliky Ustyug are often elevated, which is why there is always a threat of floods in this territory.
Depth
High water levels are considered if they lie two meters or less. Such levels are characteristic of wetlands, lowland slopes, river banks, lakes. A low level of occurrence is considered to be groundwater at a depth of more than two meters. This is the normal bedding level for building a house. The depth of the water flow means the upper underground layer, the formation of which is facilitated by the annual precipitation, rivers and lakes located nearby. Not only the construction of residential buildings, but also the organization of the landscape, planting of plants and trees depends on the depth of groundwater . If the site is located in a high-lying area, you should take care of proper drainage. Before construction, laying the foundation, conduct a depth study.
Floods in Veliky Ustyug
High water levels and, as a result, threatening floods and floods have been haunting the city of Veliky Ustyug in the Vologda Oblast since the sixteenth century. It was then that the Veliky Ustyug Chronicle first mentioned the destruction that water brought.
The most famous flood occurred in 1998. High water levels in Veliky Ustyug led to disastrous consequences. In the spring, a sharp rise in the water level began in the Sukhona River , which was facilitated by an intensive ice drift, which led to congestion. Then the city of Veliky Ustyug and twenty-four other settlements became a flood zone.
In the spring of 2016, more than one and a half thousand houses were flooded in the Vologda Oblast. The water level in the river increased by fifty centimeters per day.
In the XX century, in Veliky Ustyug, twenty-one emergency situations were recorded associated with rising water levels.