Rainwater runoff management

Kuchyňka, z.s.

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Rainwater runoff management

Summary

The community of city gardeners has built a sophisticated system of rainwater runoff collecters to reuse the water for irrigating the vegetable garden. The system comprise of different roofs equipped with gutters, plastic reservoirs, water well and high capacitive reservoir cover by floating panels with water plants to clean and protect the collected water. Water is then used to water vegetable beds by common irrigation system.

1. Organisation hosting the activity

Name

Kuchyňka, z.s.

Legal status

Registered association

Year of establishment

2013

Location

Prague, Květinářská, 182 00

The Kuchyňka Community Garden was created on a steep southern slope of 3000m2 with the intention was to grow vegetables for the CSA. After a big drought in 2015, it became clear that better water management and new measures for more intensive production cultivation were needed. Gardeners restored the local well, a whole system of rainwater catchment measures was established – a green-roofed tool shed, rainwater downpipes from the roofs of all buildings (building, marquee, pergola) and  a large-capacity catchment tank was built. There are plans to build swales or a drainage system for part of the garden in the future. The CG  could not have been created without the support of some organisations such as AMPI or grants involving both the necessary finances and soft skills. The land owner has also been a great support, claims rent of a symbolic height and co-finances e.g. the restoration of the well.

2. Activity detailed description

All water management at the CG is handled by the head gardener, Ondra, and the other members of the community garden help to operate the water on his instructions. A varying number of people are involved in the activity. Mainly men help with the hard work of building it, and about 5-10 community garden members are involved in the actual irrigation on a recurring basis, where good communication is needed and people need to be willing to get involved. The role and competences of the main gardener Ondra are crucial. At first he was just an active member of the community, later he became the main gardener. Gradually he improved his skills in growing crops in the complicated conditions (e.g. he took a course in permaculture and rainwater management). Beyond his enthusiasm for gardening he has lived on the plot for several years. The example of the CG Kuchyňka and its main gardener Ondra shows the general competences that the main leader or hte CG instructor should have – a community spirit, active involvement in the garden maintenance, appropriate education, experience and ability to share it.

The Community Garden has benefited and continues to benefit from collaborations with several other organizations. AMPI, which is linked to the Kuchyňka CG in the form of several founding members, has been most instrumental in the development of the CG and its activities. AMPI helped with the first project and funding, organizing field trips and more recently with the operation of the local garden nursery. Additional support and funding came through the Via Foundation’s support of community projects. In the initial phase, Kokoza was consulted on the establishment of CG then they worked with CAS TRIPS to run field trips for students. The field trips focus on informing the participants not only about the cultivation at CG but also about the possibilities of water conservation in the city. There is an effort to inspire them to make an ecological change in their thinking and way of life.

The main challenges with the organized activities are in the form of document preparation and in the implementation of the actual water catchment measures. The big tricky part is the terrain itself, where rainwater runs off quickly from the permeable slope. As far as the community members themselves are concerned, their involvement in the activities is a big challenge as they lack the desire in the community to do these things voluntarily. People are often overwhelmed and want to have fun and spend their free time rather than organising or doing extra work. This is probably due to the fact that they do such activities voluntarily. The solution could then be to find a long-term financial reward and turn voluntary activities into a regular job, which has worked well for one-time grants, for example.

Implementation steps

The rainwater collection includes a wooden tool shed with a green roof, a meeting building with rain collection in the gutters, and then IBC tanks. From these, water can be distributed to a nearby vegetable beds by gravity or pumped into a large catch basin. This basin is 2.5m deep, lined by a pond liner (rubber). Gravel-laden containers with aquatic plants are float on the water level as a pontoon. The plants purify the water and cover the water level to prevent evaporation. In the future, fish breeding is considered. The water from the basin is distributed by drip irrigation to the vegetable beds. It took more than a year to build the basin.

To implement similar water management system, following steps are recommended:

  • soil and subsurface survey
  • detailed plan
  • water supply construction (underground or on surface)
  • water catchment system construction (gutters and pipes)
  • water irrigation system construction

Funding and some of the expert advice or work was made possible through a grant from the Via Foundation and AMPI (a project on land development in climate change). Excursions are also still being carried out in collaboration with AMPI, with the aim of making people aware of what it means to grow, compost and manage water today. Ondra, the gardener, and some of the garden members participate in guiding the participants through the excursions, partly paid and partly on a voluntary basis.

During building the stormwater detention system, the largest items were the rehabilitation of the well and the construction of the detention basin. The well costs about 6100Eur (150 000Kč) and 2/3 of it was financed by the land owners and the rest by CG Kuchyňka. The collection tank then cost about 2900Eur (70 000Kč) for professional work and materials and about 2/3 of this was financed by a grant obtained through AMPI and the rest from CG Kuchyňka. The project of building the tank took 5 long years, because it was primarily based on hundreds of voluntary hours of CG members, including paid hours of the main gardener Ondra. 

As far as the complexity of the operation is concerned (operating the barrels, the irrigation system and refilling the tank), there is an effort to make it as independent on people as possible, but someone will always have to keep an eye on it.  Without irrigation, the operation is not time consuming but needs to be checked regularly. With irrigation of the beds, operators are also needed every day during the summer and it takes on average about 2h per week. The whole system then works mostly using electricity (pumps), some irrigation can be self-fed from IBC tanks at the main building.

Most of the rainwater that is collected in the IBC tanks is captured at the main building. This was again co-financed by a project with AMPI (a grant to pay for the architects and the final design of the building) and the actual construction of about 16,300 Euros (400,000 CZK) was then financed again by the owners of the land and gradually repaid by CG Kuchynka each year from the membership fees as part of the running costs of the garden.

3. Gallery

4. Conclusions

The ability to retain rainwater is essential for today’s productive vegetable growing. There are many ways to work with water, which are mentioned above, but solutions can be added, such as mulching of some crops, which is done in CG Kuchynka primarily to protect the soil from drying out and to protect it from weeds. Other arragements such as swales are still to be implemented. The total cost of building and implementing the activities would not have been possible without grant funding. The actual operation of the community garden is already managed almost self-sufficiently by the entire community of CG members, with members contributing to the work in the garden within their time and human capacity. Since its foundation, the CG has been very actively involved in networking of CGs and CSAs in Prague and the Czech Republic. Members of the garden are happy to share their know-how with others interested in related topics and thus support the development of other CGs and CSAs.

The whole build up of facilities and activities has taken from 2014 to now (2022) and there are still plans for improvements in the future. If there was more funding, someone could be hired and work could be done quicker, a lot of things have been done as DIY and that takes a long time. Everything has been done in stages (depending on finances and people) so that there could be productin as soon as possible.

Advice / Recommendation

"From own experience, CG Kuchyňka can recommend to work with experts to save time, money and avoid unnecessary mistakes in the future. Before you actually start to build anything, it is neccesary to consider local weather and geological characteristics to plan all details such as trees, beds, buildings, water management and irrigation systems on the site. It is helpful to see other local good practice solutions. In the case of self-build larger structures, both technical and design solutions should be consulted by professionals. In the context of recurrent excursions, it is advisable to find financial resources to pay people dedicated to this activity".