Grinda undertakes another sustainable water management project: reconstruction of sewerage networks in three districts of Vilnius begins

In recent years, the intensification of watery rains has caused considerable headaches for urban planners and engineering infrastructure maintenance companies. In the northern urbanized area of ​​the capital, rainwater is collected and discharged into the river Neris without treatment by the main 2 x 1.8 m Iron Wolf collector. As the hard surface area increases, the loads on this collector increase; already during sudden summer rains, up to 30 m3 / s of collected water flows in the residential areas of Šeškinė, Pašilaičiai and Fabijoniškės. In the future, the currently designed North Street will be connected to this collector, so it is obvious that the collector capacity will not be sufficient soon.

Choose an advanced alternative

There are several ways to solve this problem, each with its own advantages. For example, it is possible to increase the capacity of an existing collector by placing additional pipe nearby. However, this method is extremely expensive and inefficient: the cost of installing high-capacity infrastructure is high and it would only be fully used 3-4 times a year during summer rains. Alternatively, rainwater can be stored in seepage tanks and reservoirs and allowed to absorb into the ground or be discharged into an existing sewer in a controlled flow.

Grinda has chosen an advanced and sustainable form of stormwater management: diverting part of the flow to a storage pond. It would have access to already treated water, and the pond itself and its accesses would be adapted for the rest of the population. This approach is in line with sustainable urbanism and has many benefits.

Groundwater levels (an indicator of the stability of the local ecosystem) are maintained by flooding and gradually injecting rainwater into the ground, rather than instantaneous runoff into surface water bodies, and areas are protected from flooding. Rainwater treatment protects groundwater and surface water from contamination, and orderly rainwater reservoirs and their environment not only help foster biodiversity, but also become a space where people can relax.

Benefits of sustainable water management

• Groundwater levels are maintained by trapping rainwater and gradually injecting it into the ground, rather than by instantaneous runoff into surface water bodies.
• Urbanized urban areas are protected from floods.
• Rainwater treatment protects surface and groundwater from contamination.
• Open rainwater reservoirs and their environment contribute to the promotion of biodiversity.
• Open rainwater reservoirs become a suitable space for recreation.

Pipes are also built underground.

At the intersection of Ukmergės and Šiaurinės streets, it is planned to install a distribution chamber, from which the flow of surface sewage of about 9 m3 / s will be directed by a new pipeline to the storage formed between Ozo and Miglos str. This solution will help regulate water flows, reducing Geležinio Vilko street by almost a third. the maximum loads on the collector. The water from the storage pond will be discharged into a small stream with a new connection to the currently reconstructed T. Narbuto Street. collectors – thus implementing the reconstruction of the Šeškinė – Geležinis Vilkas rainwater networks, the extremely important engineering infrastructure projects of Vilnius will be elegantly connected.

Construction work will include:

• Installation of approximately 1.8 km of DN 2250 mm surface sewage networks from Šiaurinės and Ukmergės str. intersection to the Ozo str treatment plant
• Approximately 3 cu. m / s capacity for construction of a surface wastewater treatment plant.
• Approximately 20,000 cubic feet. meter. construction of a storage tank suitable for recreation.
• Installation of approximately 1.3 km of DN 1000 mm surface sewage network in Žvėrynas and connection until 2020. rebuilt T. Narbuto st. collector.
• The total length of pipes of various diameters installed during the project is 3,162 m.

The Šeškinė – Iron Wolf Basin surface sewage reconstruction project is being developed using digital construction tools (BIM). The estimated value of the works is 16.7 million. EUR.

From the distribution chamber Ukmergės st. fiberglass reinforced pipe to Calle Ozo and from Calle Ozo. – to the treatment and storage plant. In order to minimize damage to existing pavements and limit traffic on the intensive streets of Ukmergės and Ozo to a minimum, the networks will be carried out using closed microtunnels, that is, underground excavation. Work and reception wells would be installed in the green areas of these streets up to a depth of 18 m.

“The experience gained during the reconstruction of the surface sewage from the T. Narbuto – Saltoniški calles streets gave an impetus to implement other important urban infrastructure management works”, says Kęstutis Vaicekiūtis, Director of UAB Grinda.

Meets modern requirements

“We are pleased with Grinda, who sees a bigger picture by installing new communications that are vital to the city. In this way, not only the water drainage networks were adapted to the needs of today’s city and allow a better experience of summer rains, but also a lake, a public space for walks and recreation ”, says Povilas Poderskis, Director of the Municipality of Vilnius City Administration.

It is planned to install a surface sewage storage facility in the Šeškinė old town between Ozo and Miglos str. The main function of the tank under construction is to collect rainwater and release it gradually. The storage will be formed from the existing soil, it will have capacity for 20,000 m3 of water. In case of heavy rain and maximum flow (9 m3 / s), the pond will fill in 37 minutes and the excess water will drain in 5 hours. 30 minutes. Flow rate of 1 m3 / s. On the shore of the reservoir, aquatic plants will break down waste oil products and other pollutants, and together with grass and shrub communities formed on the slopes, they will form the ecosystem of the water body.

“It is planned to install surface wastewater storage combining its main function with aesthetics. It is planned to order the environment, develop the infrastructure of paths for pedestrians and bicycles, install playgrounds and benches. We strive to make it enjoyable to spend time in the new space for both the elderly and young families with children, therefore the access to the pond is designed according to the principles of a convenient environment for all ”, he says K. Vaicekiūtis.

Experience the most advanced cities in the world.

Access to the pond has not been managed for a long time, so it is covered with low-value vegetation and weeds. The territory is difficult to reach, so some Vilnius residents do not even know about it. During the project, the plot will be conditioned and adapted for recreation. The existing pedestrian and bike path from Ozo to Miglos St. will be repaired and the playground will be moved to a new location. To ensure safety, it is planned to fence the pond and install a special observation deck.

The construction of such surface water reservoirs has begun in many advanced cities around the world, realizing that there is no point in rushing to drain rainwater or meltwater into larger water bodies and canals. As the instantaneous precipitation increases, the permeability of the collectors becomes insufficient, the urban built areas are flooded.

Although in some foreign countries this type of storage is a fairly common practice related to rainwater management, it is also gradually gaining ground in Lithuania. In Vilnius, this is perfectly illustrated by the ponds of the Oz Park (V. Gerulaitis, J. Ralio, K. Ulvydo str.), Into which rainwater flows from the roofs of the surrounding buildings. In addition, this area is suitable for recreation.

Another example is the Vilnius Japanese Garden in Geležinio Vilko – Linkmenų st. at the entrances where rainwater flows into the pond. In the near future, the Vilnius city administration plans to organize this environment by creating a cozy and functional space.

The invitation to tender

The Vilnius City Municipality Company Grinda announces a new international tender: a highly competent contractor is sought, with whom a major surface sewage network project in Vilnius will be implemented. Contractors wishing to participate in the tender are invited to follow the Central Procurement Information System (CVPIS).

“The quality of the project must be guaranteed and managed already in the project initiation stage, as this will affect the quality of the project completion, that is, the results generated by the project, its use, the sustainability and the impact of the project. . We are looking for a reliable partner and we believe that we will find one, ”says the director of Grinda.

Šeškinės – Geležinio Vilko str. The reconstruction of the stormwater drainage system is part of the regionally important project “Management of surface sewage systems in Vilnius city”, funded by the EU cohesion funds, the Vilnius city municipality and the company “Grinda”. Its implementation is managed by the Environmental Project Management Agency of the Ministry of the Environment.

Order number: PT_86288041