Development of permeable layered gravel parking lots and a “sponge street” in Pestszentlőrinc-Pestszentimre district

One of the project objectives of Pestszentlőrinc-Pestszentimre (XVIII district) is the design and implementation of permeable-surface parking. The design of the 4+2 gravel parking lots with electric charging stations has been completed and the construction phase will start soon. The gravel parking lot will only serve electric cars because the permeability of the parking lot is to avoid possible oil spills from conventional cars leaking into the ground. The site selection was preceded by soil tests and detailed planning. The main challenge was to coordinate communication between planners and various stakeholders.

Gravel parking lots require more care than traditional concrete parking lots, requiring regular weeding and repaving.

The other project in the district is the transformation of a sloping street section with underground drainage blocks, rain gardens, cross-flows and tree trenches. With the redesign, the municipality wants to show how much the design of the streets matters in terms of rainwater absorption. After heavy rains, the water at the bottom of the future demonstration street section regularly accumulated so much that residents in the area used plastic chairs to signal to motorists whether or not they could drive into the street without risking getting their motorbikes wet. To prevent this from happening, rainwater run-off should start to be slowed and mitigated at the top of the street by the aforementioned water-soaking interventions.

Rain gardens and trickle filters also require constant attention, and in the case of rain gardens, the district hopes that local residents will take on the care and maintenance of these. Not many people attended the public forum, but once the street section is completed, it will be essential to establish a proper dialogue.

The construction of the gravel parking areas and the demonstration street section will start in late 2023 and is expected to be completed in 2024.

This year, rainbarrels have also been distributed in the district, some of which are equipped with measuring instruments, contributing to a more accurate rainfall map of the district.

These were complemented by four meetings involving stakeholders in stormwater management.

 

The green areas near Klauzál Square in Erzsébetváros (VII. district) will be irrigated from an underground rainwater tank

In 2023, the Municipality of Erzsébetváros also distributed rainbarrels to the district’s apartment buildings, including those with meters. Although there was some interest, it was observed that the communities that requested barrels (for watering) were more likely to be those who already maintained or even created a garden in the building. This shows the need for further awareness raising and for each condominium to be responsible for both the garden and rainwater harvesting. Also challenging in some places was the “installation” of the rainbarrel: i.e. the connection to the gutter.

The other big task here was the design of the demonstration sites, including the redesign of Klauzál Square, where an underground rainwater harvesting tank will be installed. Rainwater from the roof of the market building will be pumped into this tank, which will then be used by watering trucks to irrigate the green areas around the market. Consultation with the public was key here, as the reservoir also extends under a nearby apartment building. The full tank will hold a total of 2 weeks’ worth of water.

The roof of the Klauzál Square Market Hall (source: kunyho.hu)

In addition to the Klauzál Square project, two kindergartens in Erzsébetváros are also expected to receive investment. One of these is the “Csicsergő” kindergarten, where the existing irrigation system is to be replaced (or, in drier periods, supplemented) by rainwater from a rainwater harvesting tank in the basement. The other nursery is the Magonc nursery, which also plans to have a tank to collect rainwater run-off from the roof, possibly a rain garden. Construction is expected from spring 2024.

 

Through a series of online working group discussions, the XII. district Hegyvidék found the location of the underground rainwater harvesting cistern

The year 2023 in the Hegyvidék was spent selecting and planning suitable demonstration sites. This encountered a number of obstacles, as it turned out that it is very difficult to find a site that is both a suitable location for intervention and that is owned by the municipality, has a suitable soil structure and no utilities running underneath. Due to the complexity of the criteria, none of the 8 sites selected in autumn 2022 were decided upon, so new sites had to be selected in 2023. To this end, an online working group was set up and met weekly to discuss options. The working group included all relevant stakeholders, such as the members of the Hegyvidék Green Office and the Urban Development Office, as well as the district’s architects, landscape architects, Trinity Enviro Ltd and the BME. After several rounds of consultation, the 2 new cistern locations were identified, one in Öröm Street and the other at the intersection of Diana and Gyöngyvirág Road. The studies found that both sites can capture and retain sufficient water, while the first site is at risk of flooding, the latter is a matter of prevention and protection of other areas downstream. In 2024, the municipality will install 20 cisterns in Öröm Street and 30 cisterns at the intersection of Diana and Gyöngyvirág Road, equipped with online tracking meters. The water collected in the cisterns will be used to irrigate the surrounding fields and apiaries in the summer by the irrigation carts.

In addition to the selection of cistern sites, the other major challenge was the selection of the location of the rain gardens, which also requires a long period of strategic planning, again adapting to the existing infrastructure and the complexity of a capital city, which is not an easy task.

In 2023, the district collaborated with the Meteorological Service on climate modelling, organised workshops for Budapest districts, lead project-level consultations and raised awareness by distributing rain barrels and promoting ponds in gardens. In 2024, awareness-raising will be continued by publishing a brochure on water management

 

Towards a comprehensive metropolitan rainfall strategy at the Municipality of Budapest

Budapest Municipality is preparing a comprehensive rainfall strategy for the capital through the LIFE in Runoff project. As a first step, the municipality sent out a detailed questionnaire to all districts on climate-adaptive stormwater management, and based on the feedback from 21 districts, a problem map was drawn up.

The questionnaire was followed by the acquisition of the measurement tools needed to build and refine the runoff model for the areas under study. A flat-roof list of the capital’s institutions has been drawn up for the installation of the meters.

The Budapest-level precipitation strategy will be in line with the guidelines of the Integrated Municipal Water Management Plan, coordinated by the National Water Directorate General and published with the assistance of the Water Management and Water Engineering Section of the Hungarian Chamber of Engineers.

Since most of the capital’s land is private, not only physical investment but also awareness-raising is of paramount importance, which is why the current six-part Green Infrastructure booklet series will be expanded with two more volumes, one of which will be entitled “Sponge City – Development Opportunities for Stormwater Management in the City”. Experts from the Budapest University of Technology, the Pest County Chamber of Engineering and renowned landscape architects are also involved in the writing of the book. The second volume will be titled Green Roofs, in which the National Association of Hungarian Garden Builders will help the public learn about the construction and operation of green roofs, their types, the relevant legislation, and design aspects.

Wastewater treatment plant districts were the starting points for the meetings organised by the Climate Friendly Municipalities Association

In 2023, the Alliance of Climate Friendly Municipalities launched district stakeholder meetings tailored to the wastewater treatment plants’ areas because rainwater flows into the sewers (unless it is collected and treated on site) and the final recipient is the wastewater treatment plant. It is therefore necessary to start from the technical capabilities of the plant, i.e. how much water it can treat, and to adapt the interventions of the surrounding districts accordingly. If stormwater is not captured and treated locally and the site is oversaturated, the stormwater mixed with wastewater will flow untreated into the Danube, with potentially harmful environmental and health impacts.

Trinity Enviro Ltd. expert Bence Fülöp presents

The meetings related to the area of the South Pest Wastewater Treatment Plant were attended by professionals from the XVIII, XIX, XX and XXIII districts. Both sessions were attended by 25 people, and it was a success that the Mayor of Soroksár also attended the event. The main topics discussed were, in addition to good practices, pitfalls and difficulties of public involvement.

The main lesson was that dialogue and cooperation across districts are very important and more forums like this are needed.

The events organised around the Budapest Central Wastewater Treatment Plant and the Buda and North Pest districts will take place in spring 2024, followed by national events.