IVS – About us

IVS – Istarski vodozaštitni sustav d.o.o. (Istrian Water Protection System) is a company in the ownership of all towns and municipalities in the Region of Istria.

Objava: 3. listopada 2022.

IVS – Istarski vodozaštitni sustav d.o.o. (Istrian Water Protection System) is a company in the ownership of all towns and municipalities in the Region of Istria.

IVS – Istarski vodozaštitni sustav d.o.o. (Istrian Water Protection System) is a company in the ownership of all towns and municipalities in the Region of Istria. It was set up for the purpose of delivering the project of the ‘System of Public Drainage and Wastewater Treatment for Small Settlements under Sanitary Protection of Drinking Water Sources in the Region of Istria’.

In the course of its establishment, company shares were also owned by Hrvatske vode and the Region of Istria. However, this was amended in 2012 for the purpose of harmonization with the latest amendments of the Water Act. The company seat is in Buzet, in the old building located within the Istrian Waterworks (Istarski vodovod) site. It employs 10 workers.

Ever since its establishment, company key activities have been focused on the preparation of project documentation for collector networks and wastewater treatment devices for small settlements in the Region of Istria. Company operation will soon expand to the provision of utility services.

Ownership structure

Click the link below to open a document on the company ownership structure and the division of business shares as at 1 September 2016.

Ownership structure and business shares

The system of public drainage and water protection under sanitary protection of drinking water sources in the Region of Istria

Dut to the specific soil configuration as well as the characteristics and the abundance of drinking water sources across the Istrian peninsula, the need for the integral water supply and drainage management has arisen. The resolution of wastewater drainage and sewage has been recognized as an issue by small settlements which lack both economic and human resources to build and manage the sewage system.

For the purpose of project delivery, IVS – Istarski vodozaštitni sustav d.o.o., a company owned by towns and municipalities, the Region of Istria and Hrvatske vode, was set up. The Region of Istria has adopted two new resolutions: the Decision on Zones under Sanitary Protection of Drinking Water Sources in the Region of Istria and the Decision on Introducing a Separate Charge for Co-Funding the Construction of the Public Drainage and Water Protection System in the Region of Istria, in the amount of 1 HRK/m3 of used water.

Apart from company own funds allocated to system financing, the project also counts on the fianancial aid from Hrvatske vode and the European funds.

Basic water protection project data

The study on the ‘Organization, construction and maintenance of the wastewater drainage and treatment system for small settlements within the water protection area in the Region of Istria’ encompassed 173 settlements under zones of sanitary protection of drinking water sources in Istria inhabited by 38,000 people.

The construction foresees the erection of about 550 km of gravitational collectors, 22 km of pressure collectors, 190 pumping stations and 166 wastewater treatment facilities which capacity ranges from a low 100 population equivalent (PE) to a high 500 PE for a total of 45,400 PE.

A number of separate collector systems have been planned under the project, each with the accompanying small treatment device. Such an approach has been adopted on the basis of economic feasibility as the price per collector kilometer often exceeds the price of a small wastewater treatment device. For achieving a price reduction, the centralisation of the system control, operation and maintenance has also been planned.

Drainage and wastewater treatment systems for small settlements within the water protection areas and the Region of Istria

Project delivery company

For the purpose of a successful delivery of this very demanding project titled ‘The System of Public Drainage and Wastewater Treatment for Small Settlements within the Zones of Sanitary Protection of Drinking Water Sources in the Region of Istria’, a team of people with sufficient knowledge and experience had to be appointed.

The Assembly of the Region of Istria decided to entrust the project delivery to a team of experts that had successfully carried out the Istrian Water Supply System project.

Pursuant to the decision specified above, the Company Agreement on the establishment of IVS – Istarski vodozaštitni sustav d.o.o. with its registered seat in Buzet was signed on 23rd September 2004 in Pazin, the first constituting Assembly held, the Supervisory and Management Board appointed. The company ownership sttructure at the time of its establishment was the following: 51% was owned by the towns and municipalities of the Region of Istria, 26% by Hrvatske vode and 23% by the Region of Istria. At that stage, the town of Pula and the Medulin Municipality were not part of the ownership structure. However, they have recently expressed interest in buying a share in the company.

At the Assembly held on 25th April 2006, the Investment Programme for the Construction of the Public Drainage and Water Protection System was adopted focusing on the construction phase I as well as on the system construction schedule taking into account the size of settlement, the size of the source in the zone of a settlement as well as potential adverse effects on said source with regard to the vicinity or the source protection zone.

During 2012 and pursuant to the Water Act, the Region of Istria and Hrvatske vode transferred their shares to all local self-government units in the Region of Istria, including the town of Pula and the Medulin Municipality.

Company objectives and challenges

  • The construction and the management of the Istrian water protection system;
  • the construction of the drainage and wastewater processing system in small settlements according to the highest standards;
  • maintaining the system as designed while providing a high level of service to its users.


Legislative framework of the project

The project was based on the Water Act (OG 107/95, 150/05) and the Rules on setting the sanitary protection zones of water sources (OG 55/02), under which local self-government units had to define water protection zones. Although protection zones of individual water sources allocated to water supply in Istria had been defined even earlier, the Assembly of the Istrian Region passed a single Decision on 1 August 2005 on sanitary protection zones of drinking water sources in the Region of Istria. This Decision, which became valid for the entire territory of the peninsula, provided precise definitions of the following:

  • protection zone areas,
  • sources and accumulations used or allocated to public water supply on the territory of the Region of Istria,
  • measures for the protection of sources against pollution or other influences which might have an adverse effect on water abundance, quality and health safety,
  • continuation of the research,
  • penalty clauses.

Legislative framework- related documents can be downloaded from the Right of Access to Information section – here.

Value assessment and the method of financing

A two-tiered project delivery was planned: phase one will include the towns located in drinking water source protection zones II, III and IV (first 86 settlements). Phase two will include the systems in insufficiently researched zones as well as those outside the protection area. According to the 2000 study, total investment was assessed at about EUR 147,500,000.

The value of the first phase investments was assessed at about EUR 75,000,000 for construction and assembly, equipment, project documentation, study, property-legal affairs (land purchase), supervision, etc.

The construction funding was planned and regulated under the following:

Water Act
Water Management Funding Act
Utility Services Act.
Funding sources were planned as follows: water protection fee, special charge, loans and funds, as well as other sources.

The introduction of a special charge of 1 HRK per m3 of supplied water in water supply across the county territory ensures own funds which account for about 28% of the project total value. The final project delivery requires the financial aid by Hrvatske vode as well as by the European Union. Therefore, the first phase of this project has already been notified and accepted by Hrvatske vode for pre-accession funding.

Wastewater treatment technologies

A development of terms of reference for designing the system in the first 26 settlements was conditioned by the consent of Hrvatske vode, which have set the treatment efficiency norm: 98% removal of KPK and BPK5 in protection zone II, and 95% removal of KPK and BPK5 in protection zone III. As the 98% purification can be met only by the MBR type device (membrane bioreactor), such a device was selected for all settlements in source protection II. Furthermore, as there is no watercourse for the reception of purified wastewater in some settlements, such water shall be discharged underground which requires the highest level of effluent quality safety i.e. the MBR device. Apart from the above stated, in order to prevent any further eutrophication of the Butoniga accumulation, its watershed was also equipped with the MBR type devices in light of their efficiency in the removal of nitrogen and phosphorus. The same devices were also selected for the settlements which experience the intensive expansion of urban zones as well as for the settlements with the existing industrial production. The same principle was applied to the next 15 settlements for which the design process should commence this year. Classical biological devices BIO-TIP were selected for the so-called less sensitive areas, as well as compact SBR (sequencing batch reactor) devices for the smallest systems.

Regarding the issue of sludge removal from the devices, finding the integral solution has been in focus since the beginning. Some of discussed technological solutions included finding the solution on the existing devices in Istria, the construction of own permanent or the procurement of the mobile dehydration device. Each of these proposed solutions had its benefits and disadvantages, both of which have to be evaluated in detail prior to the passage of the final decision. During the early phase of the priority construction of devices project, all of which are MBR type, the autonomous resolution to a sludge dehydration issue by a bagging system has been planned. The technology is very simple: small (25-50 l) bags made of porous material are filled with previously thickened sludge, from which the water that has drained in the course of nature is returned into the purification system. The bags are then additionally air-dried. The potential of using such a by-product in agriculture needs to be researched.

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