24.8.2023: I decided that the “Water and Making Ponds” is too wide in scope and therefore difficult to structure in a sensible way. I am making a revised design just about the ponds: Design 1: Ponds at Iso-orvokkiniitty. That opens the possibility to make separate designs about
- Household water system at Iso-orvokkiniitty
- Plants for the Ponds
- The Technical Wetland
I am moving this to Background articles.
I am publishing this design here on my Diploma web-site for the first time on 5.1.2022. It now includes Survey, Analysis, Design of the Ponds and Design of the Plants and Implementation of the Ponds (excavation) and some thoughts about Maintenance and Evaluation. So it is not final.
On 11.10.2022 I did a presentation about our water system to the Yrkeshögskola Novia (University of Applied Sciences) in Swedish: “Vattenhantering i Iso-orvokkiniitty”. The powerpoint I prepared is a mix of Swedish and English and I have attached it here. At that time I also read the design and did some editing.
- EARTH CARE:
- The water system should rely on local resources in terms of water sources, energy and material.
- There should be no outputs from the system in terms of waste water or nutrient leaching (Biogeochemical cycles).
- The system should support wildlife and biodiversity on Iso-orvokkiniitty.
- PEOPLE CARE:
- The system should provide us with sufficient water for our household and cultivations.
- The main pond should be large enough and water quality good enough that it is possible to swim (from sauna / for children)
- FAIR SHARE:
- The system should enhance a beautiful landscape and provide recreation for us and visitors.
- The design and experience is shared with others for inspiration.
- The water system and ponds will support nature and be there for the enjoyment and benefit of future generations
OBREDIMET
OBSERVE, EVALUATE, DESIGN, IMPLEMENT, MAINTAIN, TWEAK
Content

- The vision
- Observe
- Evaluate
- Designing Ponds
- Ponds: Sources of information
- The main takeaways from “How to build a natural swimming pool”
- The main takeaways from the “Million Ponds Project”
- Placement of ponds
- Changing Zones (missing chapter)
- PMI of ponds and elements
- Scale of permanence
- Planetary boundaries
- Defining targets for excavation
- Implementation:
- Designing plants
- Vision for designing the plants
- Flowform steps and Technical Wetland
- Plants for TWL
- Perennials
- Coniferous trees and bushes
- Pond zones 2,3 and 4: wetland, swampy and shallow water
- Pond zone 5: floating or submerged plants
- Plants that are too competitive and should be avoided
- Area that is bare clay after excavation. Seeded with meadow plants.
- Sensitive trees planted north of Clean water pond beside rocks
- Budget
- Implementation Backlog
- Maintenance
- Evaluation
- Evaluate the design process
- Water for the household
- Pond excavations
- Marja’s interviews
- Using Permaculture Design Principles
- What tools were used
- Tweaks
The Vision:
Vision | Principles and Considerations |

Observe

I have covered some of the survey part already in the previous articles. In 60 DEGREES NORTH, 23 EAST I included climate data from which I show the rainfall and evaporation graphs also here. The main points:
- Rainfall per year is 700-750 mm of which 380 mm during the growing period.
- Precipitation is 300-400 mm higher than evaporation so on annual level there is a huge oversupply of water.
- Nevertheless late spring and early summer draught is typical when rainfall is low and evaporation high. This period is critical for cultivation.
Design principles so far
Our idea when designing the house in 2015 was to build an off-grid ecological house from natural materials. We wanted a closed system not only for electricity but also other energy (heating) and water. We wanted our water to come from a traditional ring well where even a hand pump could be installed (as compared to a drilled well which is typical today) and the pump supplying the house is accessible for maintenance inside the well. The region where we are potentially has radon in the base rock so that is one more reason not to do a drilled well.
In our original design we were also planning to use roof collected rain water in the house but that was not realised.

On the other end of the water pipe we didn’t want that our waste water would be pumped 40 km to Lohja where the closest water treatment plant is. It would be against permaculture principles to use resources in order to get rid of resources. Of course we needed an environmentally responsible solution. Our original idea was a dry toilet in the house with grey water treatment on site. In 2015 a new very strict waste water legislation was anticipated that would have required quite expensive solutions even for grey water treatment. At that point the willow waste water system as developed in Denmark by Pilerensning was presented to us. It is a closed system whereby all the nutrients remain on the site and water is evaporated by the willows. There are several potential uses for the wood (willow) that can be harvested from the system. The downside was quite heavy earthworks that were required for digging the system into the field. The system also requires quite a lot of space (8×30 metre in our case).
Water for the household – Elements & Functions analysis
Let’s start with looking at how we have managed water related to our household and “living” so far (2021).
Elements | Functions | What | Where | Comment |
---|---|---|---|---|
Well | Providing clean water for the house | 5 meter ring well, 800 W pump in the well | south from house on the field edge | Purely for household use lack of water is not foreseen and the water source is good. The well had to be renovated and disinfected in September 2019 due to bird poo getting into the well with rainwater and therefore microbial values were too high despite emptying the well several times. Since then it has worked well. |
Hand pump | Enables to pump water directly from the well | An “antique” Niro hand pump | on the well | Hasn’t been installed back yet after renovating the well in 2019. Requires a roof on the well to avoid the above problem recurring. |
Kitchen | Preparing food, washing dishes etc, watering plants (inside) | Big sink with tap water, dish washing machine | In the house | Dish washing machine not used in the winter period due to lack of electricity. Hand wash with water heated on the stove. |
Bathroom | Hygiene, laundry, shower | Sink and shower, laundry machine | in the house | We are not heavy users of showers anyway – we prefer sauna … |
Hot water tank | Preserving hot water | 1500 litre tank | in the house | 3 sources of heat: solar collectors (summer), massive fireplace, dumping extra electricity. There is a period in autumn and spring when the solar collectors are not generating enough hot water but the house doesn’t need heating either. Then the fireplace needs to be used just for hot water. |
Solar collectors | Providing hot water | 12 m2 flat solar collectors (ensol.pl) | on the house roof | connected through a pressure tank to the hot water tank. Covers hot water need from March-April until early / mid October. (6-7 months) |
Massive oven | Providing hot water in the winter | 50 liter tank inside the massive oven, free circulation to hot water tank | in the living room | provides warm water during heating period October to March: 30-50°C |
Outside tap | Providing water from the well | Outdoor water tap | Under the house | Used in the garden and hosed to the sauna. The tap functions also in the winter (the hose freezes). |
Sauna | Hygiene and relaxing | Traditional log sauna | c. 30 meters NW from house | No water or electricity connection: summer water hosed from house, in the winter carried with buckets |
Hot tub | Hygiene and relaxing | Wooden 1,6 meter hot water tub for bathing (c. 1600 litres water). Heated with wood stove. | in front of the sauna | Installed in August 2021. Challenge in terms of water usage and also keeping the water clean while not changing it every time. The water filtering system helps but not using chemicals means changing the water every week. The water can be used for irrigation. |
Willow wastewater system | Manage wastewater from the house | Sewage piping from house – septic tank for solids (needs to be emptied once a year / every 2nd year), pump tank with 1200W pump, 8x30m willow area closed system. | c 80 m NWW from house | Water is evaporated by the willows. Nutrients are used by the willows and the willow is harvested for use elsewhere. Water can not leave the system unless it overflows. Water can be pumped out from the opposite end of sewage water intake, f.ex. for watering plants. The system was designed for 5 persons / 500 ltr per day (180 m3/a). In reality we are only 2 persons / 200 litres per day (72 m3). The surface area of the willow system is 240 m2 which gets 170 m3 rain /a. |


According to Motiva the average home use of water in Finland is 120 litres/day/person. 7% of people use less than 50 litres per day and 5,5% use more than 200 litres. We can presume that our consumption is less than average so it could be max 6000 lites per month or 70 m3 per year for household use. There is probably in average 3000 litres of water in our well (5 metres deep x 100 cm wide = 3,9m3) so it means we use the well volume of water twice per month just for household use.

Water for cultivation
The original design ideas related to using roof collected water and storing water in ponds – both still relevant concepts. Now a few years of observation without any heavy investment has been very beneficial for understanding how the system might work. We shouldn’t jump into design decisions too hastily in unknown terrain!

Water demand in cultivation:
- Greenhouse. The greenhouse totally depends on water from outside. We can hose water collected from the roofs by gravity or – when that is not available – well water.
- Garden: especially any new plantings and annuals: Roof water or well water.
- Seedlings in the spring: Roof water or well water.
- Forest garden plantings at least in the year of planting and following year. From ditches close to the plantings – however the ditches normally dry out by mid June. After that we can hose water from the waste water system. The water presumably has some nutrients but so far has not been analysed. The waste water system dries so that it provides very limited amounts of water by the end of July (depending on rains).
- Mushroom cultivation: For shiitake force-fruiting cold fresh water from the well is needed. The temperature difference between the log and the water should ideally be at least 15°C. That is possible to achieve only with well water, which should be changed in the basin every second day. In practise we have changed it weekly which is less than optimal. The water has been taken back from the shiitake cultivation by gravity to a 1000 litre IBC tank, from where it is used for watering the garden (again by gravity).
Water demand is difficult to estimate and the need will evolve as our cultivation systems evolve. Some estimates can be taken from “Maankuivatuksen ja kastelun suunnittelu” (Planning drying and irrigation of land)(1). Some key numbers taken from the guide:
- A grass field uses 3-6 mm water per day.
- Potatoes use 1,5 mm to 4,5 mm per day depending on development stage.
- Also fruit trees need more water towards the end of the season and early season dryness can decrease shooting and increase blooming in the following year.
- Cultivated berries (strawberry, raspberry, currants, gooseberry) each have different preferences in terms of water availability during the season.
- Raspberry and currants have a high water demand for making big berries. Autumn dryness can decrease shooting for following year
- Strawberries require a lot of water during blooming. Dryness after harvest can increase blooming the following year.
- Raspberry can suffer in the winter if soil is wet after mid-August.
- In a Spray irrigation system the aim is to irrigate as much as the soil can take at once. That means 20-35 mm depending on soil type.
- Potato and garden cultivation (including fruit trees and berries) water need for irrigation can be up to 1500-2000 m3/ha or up to 200 mm during the growing season.
- When planning a storage dam for irrigation water one can calculate 1000 m3/ha collected water during the winter and spring.
As a conclusion, if we presume 1 ha cultivated and forest garden area we need up to 2000 m3 of usable stored water to be able to irrigate optimally in almost all conditions (except extreme draught). That would mean 1000 m2 pond area with 2m average depth. Or 2000 m2 with 1m average depth. If we allow only max 20% usage of the pond volumes – due to recreational and ecological purposes of the ponds – it means that we need 5000 to 10000 m2; i.e. 0,5 to 1 ha pond area. It is clear that this is not possible or desirable so we need to decide which parts of our cultivations we need to be able to irrigate.
Our more intensively cultivated garden area in Zones 1 and 2 is approximately 1000 m2 (0,1 ha) which means we need 500-1000 m2 pond area containing approximately 1000 m3 of water.
Water sources for cultivation (summer 2021):
- Well use to be minimised. We dug a 5 metre deep traditional ring well in 2015 which has a very good supply of water. We have accidentally emptied it a few times during the summer but it replenishes quite rapidly. However the well might not have sufficient water supply for extensive watering of the cultivations. We try to minimise the use of well water for other than household purposes. However we have had to use it for watering purposes to some extent.
- My estimation above was that we use 70 m3 of household water per year. On top of that we have used water for watering the garden and for mushroom cultivation without any problems. So we could just presume that we can safely double water usage during the growing season, using 30 m3 of water to other than household use.
- Collection from roofs of buildings. We have 1000 liter IBC tanks on 2 south corners of our house and 1 more could be put in the NW corner. We can place more tanks on the upper side of the garden where we can gravitationally move water from the tanks at the house. They are not very aesthetic but I will use similar cladding as the house to cover them. A few thousand litres (a few m3) of water is good but will not last very long for watering the whole garden. The roof area of our house is appr. 180 m2 which means theoretically collecting 1800 litres of water for each 10 mm of rain. So we need 30 mm of rain to fill 5 IBC tanks. We can add water collection also to the storage building and sauna adding some 80 m2. The tanks will be full in the spring but after that their usefulness depends on collecting rainwater during the growing season: theoretically 13m3 in June and 20m3 in July.
- Ditches around the fields. The ditches are full of water in early spring when snow has melted. However they will dry out at some point in June depending on rains. I have used the ditches to water nut tree seedlings on the fields after planting them and early summer as the ditches are the closest place with water.
- Circulation of water
- Willow waste water system. The willow waste water system has been in use since 2018. So far the willows are still quite small and have not had the capacity to evaporate all the water entering the willow system. So the water needs to be pumped out so that the system is not too wet – so it is only natural to use that water for irrigation of trees and bushes. We use it after the ditches have dried and hose it to the trees over quite long distances. The pump is in a well which is 150 cm deep and 40 cm in diameter. Most of the time the pump empties the well faster than new water infiltrates into the well so while water is available quite long into the summer, pumping is quite slow. As the willows grow it is foreseen that this water source will be less available.
- Most of the 70 m3 household water ends up as waste water.
- In 2022 willows grew bigger and water availability was limited.
- Water used in shiitake force-fruiting: In 2017 and 2018 I tested the production capacity of our shiitake logs by regularly force fruiting them. Fresh well water was hosed up to the forest and after being used it was hosed gravitationally into a IBC tank for use in the garden. A “tree mushroom extract” for the plants. In 2019 – 2021 I did not have time for the exercise.
- We used two 380 litres tubes. We change the water once a week. So 2,4 m3 water per month during the season (3 months = 7 m3)
- Force fruiting was continued in 2022 when we had wwoofers to do it.
- Water from the hot water tub: Our greenhouse and kitchen garden are lower than the hot tub at the sauna which will enable us to hose the water gravitationally to the garden and greenhouse.
- 1,5 m3 per week = 18 m3 during June-July-August.
- Water from sauna is also collected and used for irrigation if needed.
- Willow waste water system. The willow waste water system has been in use since 2018. So far the willows are still quite small and have not had the capacity to evaporate all the water entering the willow system. So the water needs to be pumped out so that the system is not too wet – so it is only natural to use that water for irrigation of trees and bushes. We use it after the ditches have dried and hose it to the trees over quite long distances. The pump is in a well which is 150 cm deep and 40 cm in diameter. Most of the time the pump empties the well faster than new water infiltrates into the well so while water is available quite long into the summer, pumping is quite slow. As the willows grow it is foreseen that this water source will be less available.
- Ponds (not existing yet in summer 2021)

Drainage
Water runs through the site from east to west. The main visible water flows are the ditches coming from east /the forest and south-east. All the water flows must go to the other side of Varkalahdentie through a road pipe in the west corner of the site (PA7). The height of the pipe determines the water level on the site. Therefore water levels stay quite high on the lower parts of the site (PA7). The field itself has subsoil drainage which was installed presumably in the 1980’s. We don’t have the drainage map but drainage is from east to west. The ditches on the NE side have not been cleared for decades and probably the drainage is clogged so even the more elevated parts of the field on the east side of the field are wet due to groundwater from the forest slope coming to the surface.
Summing up the most important borders and limitations:
- The physical borders of the property have been described in previous articles, mainly: Iso-orvokkiniitty: the site
- Early summer draught in June, July
- Waste water legislation and principles: waste water should not leave the property
- The Willow waste-water system has been designed for 5 people. We are only 2 so nutrients in the system could be a limiting factor for the willow growth.
- Lack of electricity in the winter for water pumps.
- Lack of heat for hot water in the winter.
- Lack of water for irrigation.
Resources:
- In an annual perspective there is sufficient rain water.
- We have dug a traditional well that has good water supply for household and even other uses.
- We have plenty of solar electricity in the summer for moving water with pumps.
- We have plenty of solar energy in the summer for heating water with solar collectors.
- We have plenty of firewood for heating the house and household water in the winter.
- Water collection from roofs.
- Ditches bringing clean water from outside our property.
- Possibility to circulate water from waste-water system.
- Possibility to locate ponds on the field in places where there already is water or where water flows.
Evaluate
Challenges in water for the household: Summer
- The well currently has a temporary cover to protect it from rain water and animals (birds). A roof needs to be built that also accommodates the hand pump under it.
- In the summer the water system in the house works as in any modern household. Cold and hot water are available as needed as well as electricity for running the water pump and the sewage pump. Free electricity is in abundance.
- We don’t have tap water into the sauna building but that was our choice of building a traditional sauna where water is hosed or carried in.
- Water for the hot tub will be taken from the well and provide used water for the greenhouse and garden. How often the water has to be changed remains to be seen as we will not use any chemicals in keeping the water clean. A filter system will be running in the summer.
- Potentially we can hose water in the summer to the summer kitchen but it has not been realised up to now. The sink and tap are already in place.
- The willow waste water system is designed for 5 people but we are only 2 living here for the time being. The hybrid willows are probably suffering from lack of nutrients.
Challenges in water for the household: Winter
- In the autumn and winter the challenges start and they are closely interconnected to availability of electricity in an off-grid house and heating (or not) the house. I will look into this more closely in the Energy design, as it does not really relate to availability of water as such but to pumping the water, hot water and risk of freezing pipes in the winter.
- In principle the willows should deplete the water from the willow system – which is a closed earth filled basin – in the summer and then there is capacity to take in the sewage water in the winter. So far the willows don’t have the capacity to do this (have not grown big enough – maybe because of lack of nutrients) so it is necessary to pump the water for irrigation in the summer to help the willows out. 2021 is the third year and the willows should grow much bigger now.
Challenges in water for Cultivation
Challenges on the cultivation side are both practical and theoretical. The obvious practical problems we experience during the summer are lack of water for irrigation and supplying the water where it is needed. Theoretical problems relate to estimating the actual and needed water flows. All the numbers given earlier (and in graph) are crude estimates albeit they are all based on something and thereby give a much better starting point for a design than “nothing”. Years differ widely (rain, temperature, wind) from each other affecting both supply and demand of water.

The graph above shows that we could potentially cover half of the 200 m3 water demand in our garden cultivation (Zone 1 and 2) with water from the well and roof collection including circulated water (excluding the willow system). To supply the other half we need to store water from the winter and spring and for that we need ponds. The max capacity of the ponds should be 200 m3 of which half would be used in the intensive cultivation. This requires 2000 m3 pond volume. The water that is available from the willow waste water system can not be used in the intensive cultivation due to hygienic risks so it would be used for watering trees in the forest garden. The forest garden could be also watered from the ponds, but overall the forest garden would have to be maintained largely without irrigation.
PMI: water for cultivation
Element | Plus | Minus | Interesting |
Well | – clean water – sufficient for household | – not sufficient for cultivation | – appr. 30m3 water can be used for cultivation |
Sauna & Hot tub | – water can be reused for irrigation | ||
Willow wastewater system | – water and nutrients stay on site | – water is not hygienic – solids must be emptied and taken to communal water treatment station | – water can be used for irrigation – water contains nutrients |
Water collection from roofs | – water can be collected gravitationally into tanks and from tanks to garden | – aestetics of water collections systems | – 260 m2 of roof surface results in 33m3 of water in June-July |
Ditches | – Water close to forest garden | – Ditches dry in the summer | |
Ponds | – Can be used for water storage – can be used for recreation / swimming | – water level will be lower in summer limiting usable capacity – water must be pumped for irrigation | – the biggest potential for water storage |
Plants in ponds | – plants enable keeping water clean – aestethics | – plants take up to 65% of pond surface – probably necessary to weed too competitive plants | – biodiversity – some edible plants – weeding results in compostable material |
Yeoman’s Scale of Permanence
- Climate: We will invest fossil fuels in the design mainly in the excavation works and some plastic pipes. Can we compensate (or more) that with carbon sequestration in vegetation in and around the ponds?
- Landshape: Definitely we affect landshape with digging ponds and ditches and making some mounds. However it is hardly visible from a distance, f.ex. from Varkalahdentie road that passes our property.
- Water Supply: Water supply is the main focus of this design.
- Roads/Access: We need to prepare paths around the ponds and small bridges over the ditches.
- Trees: Trees will be planted around the ponds.
- Soil: The banks around the ponds are the heavy clay from the excavation. Building a topsoil will partly be achieved with time and deep rooted plants, partly with bringing new topsoil to the spots where we want to see faster results from planting plants.
- Structures: Bridges, the deck, the TWL, the Flowform
- Subdivision Fences: Not planned for the moment.
Planetary Boundaries
See “My Permaculture Design Pathway“.
Earth-system process | What can we do? |
---|---|
1. Climate change | See above |
2. Biodiversity loss | One of the main targets of the Water & Ponds design is enhancing biodiversity |
3. Biogeochemical | Plants use N and P from the water flowing through the system thereby decreasing the amounts of nutrients that get in the watershed. |
4. Ocean acidification | C-limitation strategy in the ponds |
5. Land use | We are transforming field into ponds and increasing diversity of land use. |
6. Freshwater | We are using fresh water for household and cultivation. Freshwater itself is not a critical limiting factor in our conditions. |
7. Ozone depletion | no effect presumed |
8. Atmospheric aerosols | no efect presumed |
9. Chemical pollution | We avoid all chemical pollution. |
Designing Ponds
Ponds: Sources of information
For designing ponds I am referring mainly to two sources of information:
- Wolfram Kircher, Andreas Thon: How to Build a Natural Swimming Pool. The complete guide to healthy swimming at home. 2019. filbert press. [NSP] (the book was recommended to me by Joel Tefke.) The ideas in this book are reviewed f.ex. in Lowimpact.org.
- “Million Ponds Project” in the UK: https://freshwaterhabitats.org.uk/projects/million-ponds/ [MPP]
The two are to some extent contradictory to each other as they have different targets.
“The German Landscaping and Landscape Development Research Society has published standards for private natural pools (FLL 2006): A natural pool is a pool system designed especially for swimming. It is sealed against the subsoil and comprises the swimming area and the regenerative area, and it has defined requirements in terms of water quality. The water is cleaned biologically and possibly also physically or physically/chemically.” NSP p.9
” The Million Ponds Project aims to make clean water, unpolluted, ponds for endangered freshwater plants and animals!” MPP
We wish to do both and therefor take elements from both.
The main takeaways from “How to Build a Natural Swimming Pool”
- The book presumes plastic lining of the pools.
- There are 3 or 4 key desired characteristics of a natural pool
- clear water
- no string algae or other undesirable weeds
- free from pathogens
- surrounded by lush healthy vegetation
- Natural pond water is clean due to
- self regulating plankton
- biofilm (micro-organisms on all underwater surfaces)
- plants and associated mycoritzal fungi
- Clear water is achieved by limiting algae in the water which can be achieved by reducing nutrients in water and when possible shading (p24).
- A well designed pond does not require equipment for oxygen enrichment. Underwater plants guarantee sufficient oxygen saturation (p27).
- Carbon is present in water as dissolved organic carbon (DOC) or dissolved inorganic carbon (DIC).
- DIC is in the form of CO2, HCO3(-) or CO3(2-)
- CO2 is present in significant amounts in water only if pH is below 7.
- Aquatic plants are categorised in 3 groups according to their C-assimilation: (p28)
- Fontinelis type plants mainly take up CO2
- Elodea type can use also HCO3(-)
- Scenedesmus type green algae prefers HCO3(-)
- In most natural pools nitrogen might be a limiting factor for plant growth and therefore urea is often added (p31)
- The overall nutrition level of a water body is defined as its Trophic level (p32)
- There are 2 possible strategies for achieving clear water in a pond (p34):
- Most natural pools are oligotrophic or moderately mesotrophic so algal bloom is not a problem. The main objective is to eliminate string algae.
- Minimising dissolved phosphorus
- a high concentration of oxygen and pH8 cause P sedimentation
- P can be eliminated from the pond by removing mud from the pond bottom
- iron hydroxide filters can effectively fix P
- Minimising absorbable carbon
- pH below 7 effects a reduction of DIC for aquatic plants
- low hardness of water reduces available hydrogen carbonate HCO3 thereby limiting Elodea and Scenedesmus type plants.
- Water hardness can be reduced with peat due to release of humin acid and fulvic acids but results also in lower visibility and brownish colour.
- In cool climates with soft water C-limitatioin can be the natural choice. (p37)
- Filter systems relevant for natural pools (p45):
- Hydrobotanical systems with plants (HBS) (Plant lists offered in the book)
- Technical wetlands (TWL) (Plant lists offered)
- Biofilm accumulating substrate filters (BSF) (mainly relevant in P-limitation systems)
- Basic models of Natural Swimming Pools (p82):
- Standing bodies of water without technical installations (HBS)
- ≥65% densely planted area
- Bodies of water with slow surface flow (HBS)
- ≥50% densely planted area
- Bodies of running water with technical wetland filtration (HBS+TWL)
- Bodies of running water with Biofilm-accumulating Substrate filter (BSF)
- Standing bodies of water without technical installations (HBS)
- The book contains extensive plant lists, planting advice etc that are highly relevant, but I will not reference them here in detail.
- Fish are not recommended
Main thoughts and conclusions from “How to Build a Natural Swimming Pool” for our pond design:
- We will target minimising absorbable carbon
- We will design a HSB system where a TWL can be added.
- We will not use plastic lining, in principle and because it is not necessary in the heavy clay soil we have.
The main takeaways from the “Million Ponds Project” (2)
- The best way to protect pond wildlife today is to create waterbodies that mimic the clean wild ponds common in the past. The main requirement is clean, unpolluted water.
- Recipe for a clean water pond
- Find a place with a clean water source. To do this:
• make sure the pond has natural surrounds.
• avoid linking the pond to stream or ditch inflows.
• don’t add topsoil in or around the pond. The ideal substrates for the base and banks of a clean water pond are those that are naturally nutrient-poor, like bare clay or sand. - Leave the pond to colonise naturally – don’t stock it with plants, fish or other animals.
- Make sure the pond will have few impacts during its lifetime: no frequent disturbance from dogs or duck feeding.
- Find a place with a clean water source. To do this:
- If possible make several ponds.
- Also ponds that only temporarily have water are beneficial for biodiversity.
- Fish are not recommended
Main thoughts and conclusions from the “Million Ponds Project”:
- We presume that in our area even the ditch inflow water is clean. This must be confirmed with water analysis.
- The ponds and the pond banks are pure heavy clay. Some of the original topsoil could however remain in contact with the pond water.
- The ponds will be predominantly colonised naturally but some plants will be planted and seeded.
- We will not stock the ponds with fish or crabs.
- If we eventually have ducks they should have access to only one of the smaller ponds.
Placement of ponds

Pond | Where | Why | Water source | Water output |
Garden pond | on forest edge between house and greenhouse PA3 | We wanted a pond for collecting water from the roofs to supply the garden and greenhouse and provide aesthetics in the garden. | – ditch on edge of forest/field – house drainage and roof (overflow from IBC tanks) | – use in garden – greenhouse – overflow by surface ditch to Big pond |
Clean water pond | at high end of field PA8 | The upper part of the field is naturally wet. The pond can collect water and improve drainage. | – groundwater, rain and surface water from surrounding (no incoming ditch) – the location was originally wet, probably groundwater pushing into the field from the forest (border of lighter soil and heavier clay) | – use in winery – overflow to Big pond |
Eutrophic pond | at low point below sauna PA4 | A natural low point. | – surface water & rain, overflow from sauna, tub | – use in forest garden – overflow to ditch in north |
Big pond | at low point of field PA7 | The lowest point in the field is naturally wet. Space for a big pond as main water storage and recreational use. | – main ditch entering the site from SW redirected into pond – subsurface drainage from field (PA7, PA8) – ditch from Clean pond – surface water and rain | – use in forest garden and garden – overflow back to main ditch |
PMI of ponds and elements
Element | Positives | Negatives | Interesting |
Garden pond | – close to garden and greenhouse | – needs a ditch through the garden for overflow – somewhat lighter clay soil and previous excavation for water pipe means that the pond could leak | – should help to dry the upper part of the garden which is very wet in spring due to broken subsurface drainage. |
Clean water pond | – the area is wet already so groundwater, surface water and rain should suffice to fill the pond. – overflow can feed the Big pond. | it’s a clean water pond according to “Million Ponds” definition (no ditches running in) | |
Eutrophic pond | – location below sauna | the overflow ditch has to pass the willow system. | this pond will have higher nutrient level due to sauna and tub. |
Big pond | – space for a big pond in the lower part of the field in PA7 which is already wet | – massive excavation work – large area around the pond will be bare clay after the excavation work | – a mound on the field (soil from building sight) can become an island – using hydro botanical system (HBS) and if needed technical wetland (TWL) can become a natural swimming pool – space for 25 m long deep area for swimming – large reservoir for irrigation |
All ponds | – heavy clay soil means no plastic lining of the pond is necessary | – water available for irrigation at different parts of the site. – Increase in biodiversity | |
Main ditch from SW | – enables filling the Big pond effectively – Big pond water flows keeping it cleaner – ditch originates from forest area | – part of the ditch watershed is affected by the Karjalohja main road | – water quality must be analysed for nutrients, pH, water softness and microbiology – a sedimenting pond can be dug before ditch flows into big pond to catch solids |
Ditch from Clean pond to Big pond | – will at the same time dry the wet area SW of garden | shallow ditch will increase biodiversity |
Defining targets for excavation
Garden pond
- water for garden and greenhouse
- reservoir for winter rain water from roofs
- space for planting wetland and water plants (aestethics, biodiversity)
- dry upper part of garden by guiding water from the forest edge into the pond (instead of flowing into the garden)
- shallow ditch for overflow towards the road and on roadside towards Big pond
Clean water pond
- water for vineyard and forest garden
- reservoir for winter water
- no incoming ditch: keeps water as clean as possible
- space for planting wetland and water plants (aestethics, biodiversity)
- use the pile of rocks lying close to the planned pond to create a rock habitat on the warmer north side of the pond
- leave the south and west side of the pond open (no trees)
- meandering shallow ditch for overflow towards the Big pond
Eutrophic pond
- water for berry bushes and fruit trees along the road
- reservoir for winter water
- collect water from uphill and sauna
- potential for emptying water from Willow system if necessary (and space in the pond)
- explore characteristics of a higher nutrient level pond
- space for planting wetland and water plants (aestethics, biodiversity)
- separated from Big pond with tree and bush planting area and road
- overflow past the willow system towards the ditch in the north in shallow ditch with vegetation
Big pond
- the main water reservoir
- filled with water from the main ditch and overflow back to the same
- lift the pond with banks using clay from the excavation. target is that water level is approximately at original field level.
- avoid straight lines in the banks and ditches / increase edges
- incoming ditch must start at 1 metre higher (in terms of contour)so that targeted water level can be reached
- incoming ditches (main ditch from SW and 2nd ditch from the Clean pond) enter a smaller sedimentation pond first before water flows into Big pond
- overflow must be from surface so that mud and nutrients don’t flow downstream
- enough space and deepness for swimming
- follow Natural swimming pool design principles
- 1/3 of pond is over 2m deep for swimming and open water
- 2/3 shallower area for planting the hydro botanical system (HBS) for keeping water clean
- add gravel on south bank for access into the pool for swimmers and kids
- install poles in the pond for building a deck
Implementation: excavation
So far we have used MR who is also the organic farmer leasing our fields for doing the excavation works at our site. He and his sone PR are the only ones locally who have 16 ton excavators that are needed for the Big pond excavation. However as these guys are also farmers and doing contract work for other farmers during the summer they are really busy. Therefore we decided to do the small ponds without them with a rented smaller excavator. A friend of ours with experience with landscaping gardens promised to dig the Garden pond for us over a weekend. Everything didn’t go to plan however as the rented excavator broke down and he managed only to start the work. The following weekend we hired an other man with some experience to do the the digging. I dug the Clean pond and the Sauna pond myself. Previously I had limited experience with a small 3 ton excavator. The rented excavator was an 8 ton Volvo.
Garden pond





2. The ditch between garden and forest to the left flows into the pond through a pipe we dug below the stairs. This was earlier the main source of water that was keeping the garden wet.
3. Also the ditch from the right flows downwards into the pond. Originally the subsurface drainage was taking this water away but that pipe was broken when digging the water pipe.
4. There is a subsurface drainage system under the house foundation which feeds into the pond. Also the rainwater piping feeds into the pond (some of the rain water catches into the IBC tanks in the corners of the house.)
5. Overflow is directed with a shallow surface ditch towards the road and from there to the Big pond.
6. The Garden pond has 2 “departments” the one on the left is deeper and was starting to fill up (17.8.2021).
The Garden pond
- dimensions are 7,3m x 4,1m
- surface area when full 24 m2
- estimated average depth 50 cm
- estimated volume when full 12 m3
Clean water pond



The Clean water pond
- dimensions are 9,5 x 5,7
- surface area when full 43 m2
- estimated average depth 70 cm
- estimated volume when full 30 m3
Eutrophic pond


The Eutrophic pond
- dimensions are 7,5m x 5m
- surface area when full 29 m2
- estimated average depth 70 cm
- estimated volume when full 21 m3
Big pond




















The Big pond
- dimensions are 50m x 31m
- surface area when full 1200 m2
- estimated average depth 100 cm
- estimated volume when full 1200 m3
The total surface area of the ponds is appr. 1330 m2 and volume when full 1300 m3. This falls quite a lot short of the targeted 2000 m3.
Now the ponds are dug. Next step is to design the plants. It might seem wrong to jump from implementing back to designing but while plantings were considered earlier the fact is that I did the detailed plant design the winter after excavation.
Designing plants

For designing what plants could and should be used in the ponds I am referring again mostly to “How to Build a Natural Swimming Pool”.
- What direction would the pond take naturally (Learning from nature, p135). Probably in our conditions and the setting where the ponds are planned they would slowly develop into carrs (p139). (wikipedia)
- Depth Zones (p141-142):
- Zone 1: External edges adjacent to the pond
- Zone 2: Wetland area; permanent sodden soil 5-15 cm above water level but not flooded. Wet meadow perennials.
- Zone 3: Swamp area; between 5cm above and 5 cm below water surface but can tolerate a little deeper water temporarily. Emergent halophytes from reed zone.
- Zone 4: Shallow water area; permanent water level 5-40 cm. Part-submerged aquatic plants or small water lilies.
- Zone 5: Water lily area; more than 70 cm deep. Floating leaved and submerged plants.
- The book presents several design themes of which elements of “Cottage garden” and “Flowering meadow garden” can be used in our case.

“How to Build a Natural Swimming Pool” includes a extensive plant list including various parameters that are relevant for considering each species. I am not including all that information here but I picked the species mentioned in the text that seemed relevant in our situation and added some missing species from the Finnish flora. Finally I had a spreadsheet of some 150 species which I am using to group the interesting species mainly according to depth zones.
In December 2022 I published my Design 5: Plant database for Iso-orvokkiniitty for being able to manage the plant lists more effectively in a Zoho based database. In this design I am showing both the static lists I had already made in 2021-22 and the dynamic list coming from the database. To start with they should be identical but with time the list from the database will change reflecting accumulation of data in the meantime.
Vision for designing the plants:
Vision | Principles & Considerations |
This principle can also apply to plant material in that we can use local plants, species that can be found in Finland or nearby regions and be cautious about introducing exotics. USE AND VALUE RENEWABLE RESOURCES AND SERVICES | |
This principle can also apply to plant material in that utmost care should be taken to not introduce invasive species. The plants play a key role in keeping the nutrients from flowing further into the watershed. USE AND VALUE RENEWABLE RESOURCES AND SERVICES | |
We want to introduce plants that would not spread into the ponds by themselves to increase biodiversity but with above considerations. USE AND VALUE DIVERSITY | |
This principle can be expanded to providing food and other benefits in the plants. USE AND VALUE RENEWABLE RESOURCES AND SERVICES, OBTAIN A YIELD | |
Plants are a key part in keeping the water clean. USE SMALL AND SLOW SOLUTIONS | |
Beuty is a relevant benefit when choosing plants for the ponds. INTEGRATE RATHER THAN SEGREGATE | |
In “How to Build a Natural Swimming Pool” also plants for the Zone 1 external edges are proposed.

Map no | Explanation |
A. | Incoming water from ditch. Main source of water but dries out in mid June. |
B. | Ditch from Clearwater pond. Generally dry in the summer. |
C. | Ditch from Garden pond. Generally dry in the summer. |
D. | Outflow into original ditch. No outflow after appr,. midsummer. |
1. | Island in the pond. Natural vegetation + earlier seeded meadow plants. Most notably Lotus corniculatus, Hesperis matronalis, Dianthus barbatus, Eryngium planum and Verbascum thapsus can still be found a few years after seeding them. Japanese Maple to be planted. |
2. | Mound, Flowform steps. Surrounding planted with rock garden and herbs. Water pumped from the pond with pump + solar panel. Water flows into 3. |
3. | Technical wetland to enhance water pureness. |
4. | Perennials: see plant list below. |
5. | Low-growing coniferous trees and bushes. |
6. | High growing coniferous trees. |
7. | Perennials. |
8. | Pond zones 2, 3 and 4: wetland, swampy and shallow water: see plant list below. |
9. | Pond zone 5: floating or submerged plants: see plant list below. |
10. | Gravel road to “beach” |
11. | Deck on the pond for recreation. |
12. | Path around pond made of bark mulch |
13. | Mowed path |
14. | Bridge over ditch |
15. | Area that is bare clay after excavation. Seeded with meadow plants. |
16. | Sensitive trees planted north of Clean water pond beside rocks |
17. | Sensitive low-growing trees on north side of Big Pond |
18. | Stone circle |
Flowform steps and Technical Wetland
The mound was prepared from the clay from the Big Pond excavation. It is about 150 cm high. My wish is to install Flowform steps for water that is pumped on the top of the mound with a submersive pump powered by 1 solar panel (which we already have extra). The water flows into the TWL which is a water tight basin that flows back into the Big Pond from the other end.

Aeration of the pond water is strictly speaking not necessary because oxygen is provided to the pond water primarily by submerged water plants. The main function of the flowform is aesthetic.
Information about flowforms:
- www.flowform.org
- www.flowform.info
- www.virbela.se

The main purpose of the TWL is P-limitation and thereby clear water. As the main strategy in the Big Pool is C-limitation the TWL is an additional element and much smaller than it would have to be if it was the main strategy (30% of pool area would be needed). Purification is mainly achieved by microbes but the plant roots provide a suitable environment for the microbes. The basin is filled with 40-80 cm thick layer of 1-8 mm gravel. Gravel can be arranged in the basin as in illustration from HBNSP p51). Organic material may not be added into the gravel but if bog plants are desired peat can be added on the surface. Silicate type gravel supports C-limitation as does peat as well. An overflow pipe feeds the water back to the Big Pond from the other end of the basin.(HBNSP p50)
A TWL does not require the water to move constantly. Therefore a submersive pump powered by a solar panel without battery or charging regulator is envisioned. We have an extra 250W solar panel that can be directly connected to a c. 200W 12V pump. Water is pumped depending on sunshine. The water is pumped to the flowfrom which flows to the TWL. Part of the water can be directed directly to the TWL when necessary.
Plants for TWL
Plants that could be used in a bog type TWL. The target is to have Cranberries and Clouberries as the dominant species so there will be also an ediple yield. Cranberries Cloudberries require the TWL to be bog type (acid, soft water, C-restriction). The gravel in the TWL will be covered with peat.
Sc. name | Engish name | Finnish name | Occurs in Finland | Family | Origin |
Andromeda polifolia | bog-rosemary | Suokukka | x | Ericaceae | Northern hemisphere |
Drosera sp | Sundew | Kihokit | x | Droseraceae | |
Erica tetralix | Cross leaved heath | Kellokanerva | R | Ericaceae | |
Eriophorum russeolum | Ruostevilla | x | Cyperaceae | Northern hemisphere | |
Eriophorum vaginatum | Tussock Cotton Grass | Tupasvilla | x | Cyperaceae | Northern hemisphere |
Helonias bullata | Swamp pink | Suohelonia | no | Melanthiaceae | North America |
Oclemena nemoralis | Bog aster | no | Asteraceae | North America | |
Sarracenia purpurea | purple pitcher plant | Purppuratötterö | no | Sarraceniaceae | |
Sarracenia spp | trumpet pitchers | Tötteröt | no | Sarraceniaceae | |
Sphagnum palustre | blunt-leaved bogmoss | Etelänrahkasammal | r | Sphagnaceae | |
Sphagnum squarrosum | Okarahkasammal | x | Sphagnaceae | ||
Sphagnum sp | Peat moss | Rahkasammalet | x | Sphagnaceae | Northern hemisphere |
Trichophorum alpinum | Alpine bulrush | Villapääluikka | x | Cyperaceae | |
Vaccinium macrocarpon | American Cranberry | Amerikankarpalo | no | Ericaceae | North America |
Vaccinium microcarpum | Small cranberry | Pikkukarpalo | x | Ericaceae | Northern hemisphere |
Vaccinium oxycoccos | Cranberry | Isokarpalo | x | Ericaceae | Northern hemisphere |
Rubus chamaemorus | Cloudberry | Lakka | x | Rosaceae | Northern hemisphere |
The same table coming from our Plant database meaning that it will update automatically.
Perennials
Perennials will be planted in areas 4 and 7 (Map xx). For these areas topsoil will be brought in from elsewhere as planting on the pure clay will not succeed.
The plant list below is mostly taken from Pond Zone 1 plants in “How to Build a Natural Swimming Pool”. These plants don’t require immediate access to waterbed but rather aesthetically fit to be grown around the pond. Obviously other perennials can be used as well. The only ediple plants on the list are the Daylilies so obviously we will want to add more ediple plants (perennial vegetables).
A list of wild plants that we have found naturally occurring at Iso-orvokkiniitty can be found here. (First composed in 2014.)
Sc. name | Engish name | Finnish name | Occurs in Finland (VL=invasive) r=rare | Family | Origin |
Alcea rosea | common hollyhock | Salkoruusu | x | Malvaceae | China |
Clematis viticella cv | purple clematis | Viinikärhö | Ranunculaceae | Europe | |
Rosa hybrids | Roses | Ruusut | Rosaceae | ||
Allium flavum | Yellow-flowered garlic | rikkilaukka | Amaryllidaceae | Europe, Central Asia | |
Allium schoenoprasum | Chives | ruoholaukka | x | Amaryllidaceae | Northern hemisphere |
Linum perenne | perennial flax, lint | Sinipellava | Linaceae | Europe | |
Schizachyrium scoparium | little bluestem | Preeriahahtuheinä | Poaceae | North America | |
Sedum kamtschaticum | orange stonecrop | kamtsatkanmaksaruoho | V | Crassulaceae | Far East |
Anemone nemorosa | wood anemone | Valkovuokko | x, i | Ericaceae | Europe |
Dactylorhiza hybr | marsh orchids | Liuskakämmekät | x | Orchidaceae | Northern hemisphere |
Equisetum hyemale var robustum | rough horsetail | Kangaskorte, hosia | x | Equisetaceae | Northern hemisphere |
Hemerocallis sp | Daylily | Päivänliljat | Asphodelaceae | Far East, Asia | |
Iris germanica | bearded iris | Saksankurjenmiekka | (x) | Iridaceae | Europe |
Leucojum aestivum | summer snowflake | Suvikello | Amaryllidaceae | Europe | |
Lysimachia nummularia | Moneywort | Suikeroalpi | x | Primulaceae | Europe |
Primula japonica | Japanese primrose | Japaninesikko | Primulaceae | Japan |
The same table coming from our Plant database meaning that it will update automatically.
Coniferous trees and bushes
Low-growing coniferous trees (5 on Map xx) will be planted to protect the stone circle from northern wind without shading the trees and bushes growing along the road too much. In area 6. taller coniferous trees. Imported topsoil.
“How to Build a Natural Swimming Pool” proposes pines around pools as they cause the least organic matter to accumulate in the pool in the form of leaves.
Pinus banksiana | Jack pine | Banksinmänty | Pinaceae | North America | |
Pinus mugo cv | Bog pine | Vuorimänty | Pinaceae | Europe | |
Pinus parviflora | five-needle pine | Japanin valkomänty | Pinaceae | Far East | |
Pinus sylvestris | Scots Pine | Mänty | x | Pinaceae | Europe |
Pond zones 2,3 and 4: wetland, swampy and shallow water:
I have combined pond zones 2,3 and 4 and shown them in Map xx as “8”. The reason for this is that the pond shore is mostly steep so those zones will be too narrow to define them separately. Also it can be foreseen that the water level of the pond will be lower in the summer with less inflow, more evaporation and using water for irrigation. We will also see if the pond leaks. The summer 2022 will show how it will work in practise but we can presume that the lowest water level will be 50-80 cm below the max winter level in mid and late summer (July – August). That means that pond zones 2 to 4 reach from the max winter water level to 20-30 cm below the summer water level so about 100 cm vertically and 100-150 cm horizontally in most parts of the shore. How different wetland plants adapt to this kind of changes in water level will be seen only in practise.
The main criteria for choosing plants is ediple, aesthetics, biodiversity, beneficial for pollinators and not being too competitive. The choice of ediple wetland plants is low. Cranberries are mentioned above for the TWL but probably will not succeed on the pond shore. Duck Potatoes are mentioned in NSP but I can’t find any information how it would succeed in Finland (origin N-America including southern Canada). Some experiments have been made with wild rice in Finland but they have not been very successful. However it also means wild rice would not be invasive so experiments could be done also at Iso-orvokkiniitty. The practical challenge is that seeds can’t be stored so fresh seeds need to be acquired from harvest. The sprouts of Bulrush (Typha latifolia) can be used in the spring and harvesting it could be a means of restricting its growth. It is clear that Bulrush will spread naturally into the pond so the question is only how to manage it. (List of strong competitors further below.)
Yellow iris (Iris pseudacorus) which grows here naturally on lake shores and ditches is an obvious one for aesthetics but also other Iris species can be added (see the list below). Several blooming flowers, some of which already grow naturally at iso-orvokkiniitty can be promoted.
Pond zones 2,3 and 4: wetland, swampy and shallow water:
Sc. name | Engish name | Finnish name | Finland | Family | Origin | Ediple | Pond Zone 2 (wetland) | Pond Zone 3 (swamp) | Pond Zone 4 (shallow water) | to buy |
Acorus calamus | Sweet flag | Rohtokalmojuuri | Acoraceae | Eurasia | Med. | x | x | PT | ||
Alisma plantago-aquatica | Ratamosarpio | x | Alismataceae | x | PT | |||||
Alisma spp | Water plantains | Sarpiot | x | Alismataceae | x | |||||
Alisma plantago-aquatica | Ratamosarpio | x | Alismataceae | Northern hemisphere | x | x | PT | |||
Allium cernuum | Nuokkulaukka | Amaryllidaceae | x | on | ||||||
Allium suaveolens / ericetorum | Amaryllidaceae | Europe | x | |||||||
Berula erecta | Lesser water-parsnip | Hanhenputki | r | Apiaceae | x | |||||
Butomus umbellatus | Flowering Rush | Sarjarimpi | x | Butomaceae | Europe | x | x | PT | ||
Calla palustris | Calla | Suovehka | i | Araceae | Northern hemisphere | x | x | PT | ||
Caltha palustris | Rentukka | x, i | Ranunculaceae | x | x | x | PT | |||
Cardemine pratensis | Luhtalitukka | x | Brassicaceae | x | ||||||
Carex canescens | Harmaasara | x | Cyperaceae | x | x | |||||
Epipactis palustris | Suoneidonvaippa | x | Orchidaceae | x | ||||||
Eriophorum latifolium | Lettovilla | x | Cyperaceae | x | ||||||
Eupatorium cannabinum | Rantapunalatva | r | Asteraceae | Europe | x | |||||
Eupatorium maculatum | spotted joe-pyeweed | Täpläpunalatva | Asteraceae | North America | x | x | ||||
Euphorbia palustris | Marsh spurge | Rantatyräkki | r | Euphorbiaceae | Eurasia | x | x | PT | ||
Fritillaria meleagris | kirjopikarililja | x | Liliaceae | x | ||||||
Gladiolus palustris | Marsh gladiolus | Nuokkumiekkalilja | Iridaceae | Europe | x | |||||
Hippuris vulgaris | Mare’s Tail | Vesikuusi | x | Plantaginaceae | Eurasia, North Am. | x | PT | |||
Iris ensata | Japanese flag | Japaninkurjenmiekka | Iridaceae | Japan | x | PT | ||||
Iris germanica | bearded iris | Saksankurjenmiekka | (x) | Iridaceae | Europe | x | ||||
Iris laevigata | Japanese iris | samettikurjenmiekka | Iridaceae | Far East | x | x | ||||
Iris pseudacorus | Yellow iris | Keltakurjenmiekka | x | Iridaceae | x | x | PT | |||
Iris sibirica | Siperiankurjenmiekka | (x) | Iridaceae | x | PT | |||||
Juncus spp | Rushes | Vihvilät | x, i | Juncaceae | x | |||||
Juncus effusus | Soft Rush | Röyhyvihvilä | x | Juncaceae | global | x | x | PT | ||
Leucojum vernum | Kevätkello | Amaryllidaceae | x | |||||||
Liatris spicata | Noropunatähkä | Asteraceae | x | |||||||
Lobelia cardinalis (fulgens) | Cardinal flower | Punalobelia | Campanulaceae | North America | x | x | PT | |||
Lobelia siphylitica | Great blue lobelia | Tähkälobelia | Campanulaceae | x | ||||||
Lychnis flos-cuculi | Käenkukka | x, i | Caryophyllaceae | x | ||||||
Lythrum salicaria | Rantakukka | x, i | Lythraceae | x | x | PT | ||||
Mentha aquatica | Vesiminttu | x | Lamiaceae | x | PT | |||||
Menyanthes trifoliata | Bogbean | Raate | x, i | Menyanthaceae | x | x | ||||
Mimulus / Erythranthe guttata | seep monkeyflower | Täpläapinankukka | (x) | Phrymaceae | North America | x | x | |||
Myosotis palustris | true forget-me-not | Luhtalemmikki | Boraginaceae | x | ||||||
Parnassia palustris | Vilukko | x | Celastraceae | x | ||||||
Pontederia cordata | pickerel weed | herttasoikko | Pontederiaceae | North America | x | FLÖ | ||||
Primula roșea | himalajanesikko | Primulaceae | Himalaya | x | x | PT | ||||
Sagittaria latifolia | Duck potato | Alismataceae | x | x | x | |||||
Sagittaria sagittifolia | Pystykeiholehti | x | Alismataceae | x | x | |||||
Schoenus ferrugineus | Ruskoruosteheinä | r | Cyperaceae | x | x | |||||
Sium latifolium | Great water-parsnip | Sorsanputki | r | Apiaceae | x | |||||
Sparganium emersum | Bur-reed | Rantapalpakko | x | Typhaceae | x | |||||
Thelypteris palustris | Nevaimarre | x | Thelypteridaceae | x | ||||||
Typha minima | Dwarf cattail | Pikkuosmankäämi | Typhaceae | Eurasia | x | x | PT | |||
Veronica beccabunga | Ojatädyke | x | Plantaginaceae | x | ||||||
Veronica longifolia | Rantatädyke | x | Plantaginaceae | x | ||||||
Zizania palustris | Northern wild rice | Villiriisi | Poaceae | North America | x | x |
x=Occurs in Finland, VL= invasive, r=rare, I = identified at Iso-orvokkiniitty
The same table coming from our Plant database meaning that it will update automatically.
Pond zone 5: floating or submerged plants
Most reeds are strong competitors and should not be added to the system. (List of strong competitors further below.) Bulrush (Typha latifolia) already grows in our ditches so it will probably be the main challenge in managing the ponds. Also Yellow pond lily (Nuphar lutea) is too competitive and should not be planted in the pond. Two species of water lilies occur in Finland (Nymphaea alba, N. alba subsp. candida and N. tetragona) which we want to plant in the ponds. Submerged plants are critical for the functioning of the pond so we will study what plants can be found nearby naturally and transplanted in the pond and which ones might be commercially available (generally very few water plants are available).
Brasenia schreberi, known as chuncai in China or junsai in Japan, is edible.
Pond zone 5: floating or submerged plants:
Sc. name | Engish name | Finnish name | Occurs in Finland (VL=invasive) r=rare | Family | Origin | Ediple | Pond Zone 5 (floating or submerged) | to buy |
Brasenia schreberi | Brasenia, junsai | Cabombaceae | Americas, East Asia | x | x | |||
Callitriche sp | water-starwort | Vesitähdet | x | Plantaginaceae | x | |||
Ceratophyllum demersum | Karvalehti | r | Ceratophyllaceae | x | ||||
Ceratophyllum submersum | Hentokarvalehti | r | Ceratophyllaceae | x | ||||
Chara sp | Näkinparrat | x | Characeae | x | ||||
Eleocharis acicularis | Hapsiluikka | x | Cyperaceae | x | ||||
Fontinalis antipyretica | Water moss | Isonäkinsammal | x | Fontinalaceae | x | |||
Hottonia palustris | water violet | Vesisulka | Primulaceae | x | ||||
Lobelia dortmanna | Water lobelia | Nuottaruoho | x | Campanulaceae | x | |||
Luronium natans | floating water-plantain | Kellusarpio | Alismataceae | x | ||||
Myriophyllum spicatum | Tähkä-ärviä | x | Haloragaceae | x | ||||
Myriophyllum verticillatum | Kiehkuraärviä | x | Haloragaceae | x | ||||
Nymphaea alba, candida | Water lily | Isolumme | x | Nymphaeaceae | x | PT | ||
Nymphaea cv | Water lilies | Lumpeet | Nymphaeaceae | x | ||||
Nymphaea tetragona | Suomenlumme | x | Nymphaeaceae | x | ||||
Potamogeton crispus | Poimuvita | r | Potamogetonaceae | x | ||||
Potamogeton lucens | Välkevita | r | Potamogetonaceae | x | ||||
Potamogeton pectinatus | Hapsivita | x | Potamogetonaceae | x | ||||
Potamogeton perfoliatus | ahvenvita | x | Potamogetonaceae | x | ||||
Salvinia natans | Floating fern | Kellusaniainen | Salviniaceae | global | x | PT | ||
Stratiotes aloides | Sahalehti | x | Hydrocharitaceae | x | ||||
Utricularia australis | Lännenvesiherne | r | Lentibulariaceae | x | ||||
Utricularia vulgaris | Bladderwort | Isovesiherne | x | Lentibulariaceae | Europe | x |
The same table coming from our Plant database meaning that it will update automatically.
Plants that are too competitive and should be avoided
The plant list below is mostly taken from “How to Build a Natural Swimming Pool” so it mainly reflects the situation in Central Europe. However to be on the safe side we will avoid these. Some of these species can be found at Iso-orvokkiniitty, most notably Bulrush (Typha latifolia). We also have Carex sp. in the wet parts of our fields so those will certainly be present. However I have so far not identified them on species level.
Plants that are too competitive and should be avoided
Sc. name | Engish name | Finnish name | Occurs in Finland (VL=invasive) r=rare | Family | Origin | Ediple | Strong competition | Pond Zone 3 (swamp) | Pond Zone 4 (shallow water) | Pond Zone 5 (floating or submerged) |
Elodea sp | waterweeds | Vesirutto | VL | Hydrocharitaceae | X | x | ||||
Nuphar lutea | Yellow pond lily | Ulpukka | X | Nymphaeaceae | X | x | ||||
Nymphoides peltata | Floating heart | Lammikki | VL | Menyanthaceae | X | x | ||||
Persicaria amphibia | Water smartweed | vesitatar | x | Polygonaceae | Europe | X | x | |||
Potamogeton natans | uistinvita | x | Potamogetonaceae | X | x | |||||
Carex acutiformis | Vesisara | x | Cyperaceae | X | x | x | ||||
Eleocharis palustris | Rantaluikka | x | Cyperaceae | X | x | x | ||||
Glyceria maxima | great manna grass | Isosorsimo | VL | Poaceae | Europe | X | x | |||
Ranunculus lingua | Greater Spearwort | jokileinikki | x | Ranunculaceae | X | x | x | |||
Schoenoplectus lacustris | lakeshore bulrush | Järvikaisla | X | Cyperaceae | X | x | ||||
Schoenoplectus tabernaemontani | softstem bulrush | Sinikaisla | x | Cyperaceae | X | x | ||||
Typha angustifolia | lesser bulrush | Kapeaosmankäämi | x | Typhaceae | Europe | x | X | x | ||
Typha latifolia | Bulrush, Common cattail | Leveäosmankäämi | XX, i | Typhaceae | Global | x | X | x | x | |
Zizania latifolia (caduciflora) | Manchurian wild rice | Poaceae | Far East | x | X | x | ||||
Phragmites australis | Common reed | Järviruoko | X | Poaceae | cosmopolitan | x | XXX | x | ||
Carex acuta | Viiltosara | x | Cyperaceae | X | ||||||
Carex diandra | Liereäsara | x | Cyperaceae | X | x | |||||
Carex elata | Piukkasara | x | Cyperaceae | X | ||||||
Carex riparia | Vankkasara | r | Cyperaceae | X | x | |||||
Carex vesicaria | Luhtasara | x | Cyperaceae | X | x | |||||
Equisetum hyemale var robustum | rough horsetail | Kangaskorte, hosia | x | Equisetaceae | Northern hemisphere | X | ||||
Equisetum scirpoides | Hentokorte | x | Equisetaceae | X | ||||||
Equisetum spp | kortteet | x, i | Equisetaceae | X | ||||||
Lysimachia tyrsiflora | Terttualpi | x | Primulaceae | X | x | |||||
Phalaris arundinacea | Ribbon grass | Ruokohelpi | x | Poaceae | Cosmopolitan | X | x |

Area that is bare clay after excavation. Seeded with meadow plants.
In October 2021 we seeded the bare clay area with a wide range of seeds. This included the Rantaniitty (Shore meadow) and Kostea niitty (Wet meadow) seed mixes from Niittysiemen, a bunch of other meadow plants and some seeds we collected from the lake shore nearby (Iris pseudacorus, Lythrum salicaria). How well the seeding might succeed on the bare clay is questionable but we wanted the seeds to have a headstart compared to wild weeds that would take the pond surroundings over otherwise. Below I am listing only the plants that were included in the Niittysiemen seed mixes.
Rantaniitty – Shore meadow seed mix:
Finnish name | Scientific name | Swedish name |
Keltakurjenmiekka | Iris pseudocorus | Svärdslilja |
Kumina | Carum carvi | Kummin |
Mesiangervo | Filipendula ulmaria | Älggräs |
Ojakärsämö | Achillea ptarmica | Nysört |
Pulskaneilikka | Dianthus superbus | Praktnejlika |
Puna-ailakki | Silene dioica | Skogslyst |
Purtojuuri | Succisa pratensis | Ängsvädd |
Päivänkakkara | Leucanthemum vulgare | Prästkrage |
Rantakukka | Lythrum salicaria | Fackelblomster |
Rantatädyke | Veronica longifolia | Strandveronika |
Ruiskaunokki | Centaurea cyanus | Blåklint |
Kostea niitty – Wet meadow seed mix:
Finnish name | Scientific name | Swedish name |
Aitohunajakukka | Phacelia tanacetifolia | Honungsört |
Keltamaite | Lotus corniculatus | Käringtand |
Keltakurjenmiekka | Iris pseudocorus | Svärdslilja |
Kyläkellukka | Geum urbanum | Nejlikrot |
Mesiangervo | Filipendula ulmaria | Älggräs |
Ojakärsämö | Achillea ptarmica | Nysört |
Pulskaneilikka | Dianthus superbus | Praktnejlika |
Päivänkakkara | Leucanthemum vulgare | Prästkrage |
Rantakukka | Lythrum salicaria | Fackelblomster |
Varsankello | Campanula trachelium | Nässelklocka |
Sensitive trees planted north of Clean water pond beside rocks
Generally the north side of a pond is a favourable spot for trees because they receive light both directly from the sun and as a reflection from the pond. They also have good access to water once they have grown their root system to the pond. When I dug the Clean water pond I used rocks that were lying around nearby since digging our house’s foundation to make a rock pile on the north side of the pond. That should accumulate heat and further make the spot favorable for more sensitive trees. Juglans sp and Castanea sativa had already been planted nearby earlier (2017). In 2021 I planted a Mulbery”Morus acidosa ‘Mulle'” on the north side of the pond and rocks and I also planted 2 Asiminas beside the rocks. On NW side there are 2 Bladdernuts (Staphylea spinnata).
Sensitive low-growing trees on north side of Big Pond
A patch of low-growing trees is envisioned on the north side of the Big pond (17 on Map xx) to benefit from the favourable position. Species will be defined in the Forest Garden design.
Budget
What | Cost |
---|---|
excavation, small ponds (mainly rental cost) | 2000 € |
excavation, big pond , including gravel and pipes | 6300 € |
water analysis | |
Flowform | 2500 € |
TWL: – “Firestone” pond liner 6m x 10m – gravel – excavator work – peat | 880 € 270 € 175 € x € |
Bridges – oak logs – 2”x 8” timber | |
Implementation Backlog
What | Q3/2021 | Q4/2021 | Q1/2022 | Q2/2022 | Q3/2022 | Q4/2022 | 2023 |
---|---|---|---|---|---|---|---|
Design | in the works | in the works | in the works | ||||
Build deck | to do | to do | In Progress | In Progress | |||
Survey available wetland and water plants | to do | to do | In Progress | ||||
Hand pump and shelter for well | to do | ||||||
Add IBC tank to NW corner of house | to do | ||||||
Analyse incoming ditch water from S | to do | ||||||
Implement plants | In Progress | In Progress | |||||
Prepare bark mulch paths | to do | Done | |||||
Build bridges over ditches | to do | In Progress | |||||
Dig shallow ditch for overflow from Garden pond | to do | In Progress | |||||
Build small decks for small ponds | to do | ||||||
Prepare “kivipesä” gravel filtration for sauna grey water | to do | ||||||
Order and install Flowform | Done | ||||||
Build TWL | In Progress | Done |
Maintenance
What | Q1 Winter | Q2 Spring | Q3 Summer | Q4 Kekri |
---|---|---|---|---|
Document water level in ponds | x | x | x | |
Document biodiversity in and around ponds | x | x | x | |
Copice half of the willows in the willow system | x | |||
Empty the septic tanks every 2nd year | x | |||
Collect and empty hoses before they freeze | x | |||
Evaluation
Evaluate the design and process
Water for the household
When planning the house in 2014-15 the connection between the water system and energy was not fully understood. In the winter when electricity is scarce in an off-grid house and electricity consumption is minimised the single biggest electricity consumption goes into pumping water into the house (800W pump) and pumping waste water into the willow system (1200W pump). So a big part of water and electricity consumption is linked to the water closet. An obvious conclusion is that an off-grid house should have a dry toilet as was our plan before being introduced to the willow system option. Even now I am mostly using our dry toilet in the winter but as it is outside it is not the preferred option for everyone in the freezing temperatures of the winter.
Now we have a water closet and the willow system so that cannot be changed. A partial solution for incoming water could be digging a new well higher up on the slope where our house is thereby decreasing the energy consumption of pumping water into the house. We believe that the groundwater is quite high on the slope above the existing well so this is something to consider. Other than that it is a question of electricity supply which I will address in the Energy Design.
Pond excavations
In practise designing and implementing were somewhat overlapping regarding excavations in Q3/2021. Some points were not properly communicated to the excavator operators due to this:
- What we meant with the shallow part of the pond was not clear. Now the shore is relatively steep going to appr. 1 metre depth while it would have been better to have a more gradual deepening of the shallow side of the pond to create more of pond zone 2 and 3.
- Water should not have contact to the original topsoil of the field. So even if topsoil is not taken away it should be removed from the shore so that only pure clay is in contact with the water. Now topsoil is visible in some parts of the pond shore.
- It would be good to have an higher edge where the shallow area borders the deeper area. This would prevent mud from flowing into the deeper pond area. This was not implemented at all.
Fossil fuels for excavation works:
- excavators for Big pond 58h x 20l = 1160 l
- tractor for big pond 32h x 10l = 320 l
- SUM for Big Pond appr. 1500 l fuel meaning appr. 4000 kg CO2 emissions (2,63 kg CO2/kg diesel: wikipedia).
Achieved pond volume 1300 m3 compared to targeted 2000 m3.
Marja’s interviews
Marja read and commented on the design on 2.12.2021. She was overall happy with it and commented only on some details. I created a pdf-version on 3.12.2021 for the files after corrections in the text.
Using Permaculture Design Principles
In David Holmgren’s terms (3) this design is in the domains of “Land & Nature Stewardship” and “Built Environment” and broadly speaking a “Land Based” design. The Ethics of Permaculture (Earth care, People care, Fair share) have been taken into account in the Vision which was considered separately regarding ponds and plants.
- OBSERVE AND INTERACT. The design is based on several years of observing our site and interacting with it since 2014.
- CATCH AND STORE ENERGY. This is the main design principle “Water and making ponds” as we are catching and storing water that moves through our site. When we are not moving water gravitationally we use the help of catching sun energy for running pumps.
- OBTAIN A YIELD. The water system is designed to supply water for household and cultivation while creating recreational value and biodiversity.
- APPLY SELF-REGULATION AND ACCEPT FEEDBACK. The Water system is designed to be highly self-regulated and independent of external inputs after setup. Some technical helps are needed to obtain the yield. The design is not ready in one go – feedback is expected from the system and will be reacted to with tweaks as necessary.
- USE AND VALUE RENEWABLE RESOURCES AND SERVICES. Water and sun energy are renewable and in the core of this design.
- PRODUCE NO WASTE. The water system is designed to produce practically no waste. The system output is the clean water leaving the site through the road pipe. The only exception is the waste water solids from the septic tank that need to be taken away every 2nd year (theoretically they could be composted on site).
- DESIGN FROM PATTERNS TO DETAILS. The pattern of water flowing gravitationally in the landscape through ditches and reservoirs (ponds in our case).
- INTEGRATE RATHER THAN SEGREGATE. Integration of water systems and plant systems (the different elements) to benefit each other and create several functions (clean water, catch and store water, irrigation, recreation, biodiversity etc).
- USE SMALL AND SLOW SOLUTIONS. While the main part of the excavation was done in September and October 2021, after that the system will develop slowly with a natural succession (helped with planting and seeding) of the plants and water ecology and adding necessary tweaks.
- USE AND VALUE DIVERSITY. Each pond is to some extent different from the others which increases diversity in and between them. Planted and seeded plants increase the diversity.
- USE EDGES AND VALUE THE MARGINAL. Where until now was grassland field is now ponds and ditches creating various kinds of edge effect between moving and standing water and soil and water bodies of different depths etc.
- CREATIVELY USE AND RESPOND TO CHANGE. The Water system combined with the plants will be in constant change through the seasons and succession over years. This change will build a permanent system.
Planetary boundaries / machine work
What tools were used
- OBREDIMET
- PMI
- Scale of Permanence
- Planetary Boundaries
Tweaks
(1) Lasse Järvenpää ja Mika Savolainen (toim.) Maankuivatuksen ja kastelun suunnittelu. (2. päivitetty painos). YMPÄRISTÖHALLINNON OHJEITA 4 | 2015
(2) Freshwater Habitats Trust: Help and Resources. https://freshwaterhabitats.org.uk/projects/million-ponds/help-and-resources/
(3) David Holmgren: Essence of Permaculture. 2013.
- First published 5.1.2022
- Tweaked the Design process 6.1.2022
- Added picture “The Water System connected to the House” 12.1.2022
- Added chapter Borders, limitations, resources 25.1.2022
- Edit 16.3.2022
- added principles to “Principles and considerations”
- Edit 11.4.2022: added water plants from Paratiisin Taimitarha to plant lists.