Pervious Pavement

1. Pervious Pavement “We can't solve problems by using the same kind of thinking we used when we created them." Albert Einstein. Pervious Pavements are a different way of thinking about roads. John Harrison, B.Sc. B.Ec. FCPA

2. What Is Pervious Pavement? • Pervious pavement is a permeable pavement surface with a stone reservoir underneath. • The reservoir temporarily stores surface runoff before infiltrating it into the subsoil or sub-surface drainage and in the process improves the water quality. • Permeable materials such as ancient lime mortars and pervious pavements are made using relatively mono graded materials. • Pervious pavements allow the earth to breathe, take in water and be healthy. The stone and soil under them acts as a reservoir and cleans the water just like the filter on a fish tank. • Pervious pavements are safer to drive on as they do not develop "puddles", have a good surface to grip • Subdivisions made with pervious pavement that also have street trees can be several degrees cooler than surrounding suburbs without.

3. The Water Cycle The water or hydrological cycle is powered by the sun and water changes state and is stored as it moves through it. Human intervention is reducing the time it takes for water to return to the oceans resulting in less moisture on land, salinity and aridity. Source:Illustration by John M. Evans USGS, Colorado District (http://ga.water.usgs.gov/edu/watercyclegraphichi.html)

4. Australia Before Settlement In years gone by grassland and forest covered the land

5. Our Legacy • In years gone by forests and grassland covered most of our planet. • When it rained much of the water naturally percolated though soils that performed vital functions of • slowing down the rate of transport to rivers and streams, • purifying the water and • replenishing natural aquifers. • Our legacy has been to pave this natural bio filter, redirecting the water that fell as rain as quickly as possible to the sea. • Given global water shortages, problems with salinity, pollution, volume and rate of flow of runoff we need to change our practices so as to mimic the way it was for so many millions of years before we started making so many changes. • The key to survival in the future will be learning from nature and mimicking her subtle processes. Road are the arteries, veins and lymphatic system to cities. • This presentation focuses on where we have gone wrong with roads and the radical TecEco Permecocrete solution.

6. Australia with a Little Lateral Thinking & Effort Cows – CSIO anti methane bred TecEco technology provides ways ofsequestering carbon dioxide and utilising wastes to create our techno - world Less paper. Other Cl free processes - no salinity Evolution away from using trees – paperless office Vehicles – more efficient and using fuel cells Organic farming Carbon returned to soils. Pervious pavements prevent immediate and polluted run-off. Carbon dioxide and other gases absorbed by TecEco Eco- Cements. Sewerage converted to fertilizer and returned to soils. Buildings generate own energy etc. It is essential we learn to live with nature and change our ways

7. One Planet, Many People, Many Interconnected Problems Global Sustainability Alliance Partners are in the BIGGEST Business on the Planet – Economic Solutions to our Energy, Global Warming, Water and Waste Problems.

8. Global Fresh Water • A finite resource • Population rising • Per capita use rising • Water-stress • 1/3 world's population • By 2025, 2/3 due to global warming. • 1 person in 5 do not have access to safe drinking water • Yet water is the most common substance on the planet. • Water covers 70% of the surface • Only =~ 1% is potable

9. Australia’s Water Problems • Australia is the driest inhabited continent in the world - only Antarctica gets less rain. • Most of Australia has experienced drought under El Nino conditions for the past few years. • Some major cities are seriously short of water. • Yet giga litres of stormwater go into our coastal water ways every year carrying with it significant levels of pollution.

10. Stormwater = Rainwater + Pollution • Pollution comes from many different sources, however the two main sources are Point and Non-point sources. • Stormwater is the major cause of reduction in water quality in rivers and the destruction of marine environments. • Stormwater is NOT supposed to include sewerage! • Pollution is why it is not a good idea to eat too many fish from many areas near cities Why mix rainwater and pollution?

11. Point and Non-Point Source Pollution • Point Source PollutionPoint source pollution is when high levels of pollution enter a water system such as a wetland or river from one source, such as a factory, mine, sewage plant or garbage dump. Point source pollution is easy to trace. • Non-Point Source PollutionNon-point source pollution is when levels of pollution enter a water system at various points and from various sources. This type of pollution is the most difficult to monitor and manage. The most common non-point source of stormwater pollution comes from local residents throughout a catchment.

12. Stormwater = Rainwater + Pollution Source: thesource.melbournewater.com.au/.../river.htm

13. Sources and Types of Pollution Adapted from: www.cwmb.sa.gov.au/kwc/section1/1-24.htm

14. Types of Pollution (1) Modified from: EPA stormwater code of practice from www.cwmb.sa.gov.au/kwc/section1/1-24.htm

15. Types of Pollution (2) Modified from: EPA stormwater code of practice from www.cwmb.sa.gov.au/kwc/section1/1-24.htm

16. Roads Interrupt Natural Drainage • We have dissected the landscape with roads and no matter what kind, they modify the drainage network. • Roads themselves are impervious and also capture water. • Stormwater from buildings and from properties usually goes to the same drainage system. • Stormwater = Rainwater + Pollution Various sources! Source: Keith Stichler, CBF

17. Roads are the Drainage Network And represent a huge wasted catchment

18. Impervious Watersheds Kill Rivers and Speed up the Water Cycle • There is a relationship between the amount of impervious surface cover within a watershed and the quality of surface water within that watershed. • 10 to 15% of an area is covered by impervious surfaces, the increased sediment and chemical pollutants in runoff have a measurable effect on water quality. • 15 to 25% of a watershed is paved or impervious to drainage, increased runoff leads to reduced oxygen levels and harms stream life. • If more than 25% of surfaces are paved, many types of macro and micro organisms in streams die from concentrated runoff and sediments Smith, A. (2001). New Satellite Maps Provide Planners Improved Urban Sprawl Insight, NASA Goddard Space Flight Center, GSFC on-line News Releases. The more impervious the surface the more speed, volume and pollution water acquires.

19. Purifying Water • Pervious pavements filter water falling on them releasing it slowly to sub-surface drains or aquifers and finally the sea. There is little or now surface run-off to carry rubbish into drains and streams. • Water quality is purified by the sub-pavement acting as a giant biofiliter allowing bacteria and oxygen to do their work and because surface rubbish does not contaminate it. 

20. Pervious Pavements Act Like a Giant Biofilter • Just as fish cannot be kept in an aquarium without a filter system they are not healthy in our lakes dams creeks and rivers without natural or man made filtration of run off water. • Pervious pavements and their sub structures act as a giant biofilters • Pervious pavement with integral bacteria improves water quality entering aquifers, streams and rivers. • The critical "first flush" of pollutants is sent rapidly into the cross-section where constantly available sources of bacteria and microbes exist and have sufficient air exchange capability to maintain themselves and perform their cleaning functions. Source Wikipedia. Filtration system in a typical aquarium: (1) Intake. (2) Mechanical filtration. (3) Chemical filtration. (4) Biological filtration medium. (5) Outflow to tank.

21. Speed, Volume Sediment Load and Pollution Rainwater does good all the way to the sea. Polluted and salty water do no good at all Higher speed, higher volume, more energy, greater distance covered = more pollution and salts Low speed, low volume low distance covered = low pollution and salts “The Water Dynamic”

22. Traps Do Not Stop Micro and Molecular Pollution Source www.dpiw.tas.gov.au/.../RPIO-4YJ3KA?open Traps are useless for stopping most pollutants other than those that are unsightly www.azstorm.org/public_edu.php

23. The Functions of Roads • Roads are the veins, arteries and lymphatic system of cities. • They provide • The network for • The transport of resources and wastes • Drainage • The route for all services • Water • Sewerage • Electricity • Gas • Telephone etc. • Many different people are involved

24. Current Road Designs are Not Sustainable Drainage and Traffic Engineers Sewerage Engineers Traffic Engineers Management Hydraulic Engineers Environmental Scientists Gas Engineers Ratepayers Electrical Engineers Telecommunication Engineers Geo Technical Engineers How often do you see the same section of road dug up repeatedly in quick succession? The various groups with an interest in roads do not work together holistically

25. Changing the Road Paradigm • Roads and associated services as they are today have not been thought out. They have evolved. • In the past the agencies that are responsible for these networks and services have more or less acted independently of each other resulting in • Wasted Resources • Additional Cost • How often do you see different crews digging up the same bit of road? • This is not sustainable! You never change things by fighting the existing reality. To change something, build a new model that makes the existing model obsolete. – Buckminster Fuller

26. Building a New Model • The engineering paradigm too prevalent amongst the road building fraternity is: • “Roads are for vehicles” “water on roads in dangerous” “collect it and get rid of it as quickly as possible” • Given the current water crisis can this limited thinking be allowed to continue? • Only a small % of water reticulated through a community is used for drinking. • Most is used for washing, laundry, flushing toilets or watering gardens. • Perhaps the water caught by our road drainage systems could be used?

27. Heads First for Action • Water, CO2, waste and many other issues are mostly in our heads. • We must first think differently then • Act differently! • Roads are not just for traffic • They set drainage patterns • Carry services under them • Define wildlife zones • Prevent natural percolation to aquifers etc. • Roads in the future will have to be: • Holistically designed • Take into account previously unintended outcomes such as local drainage alteration and pollution. • Capture desperately needed water • Our model, measure and mentor for change must be nature. John Harrison with pervious pavement. Photographer Peter Boyer

28. Our Guide - Biomimicry - Geomimicry • The term biomimicry was popularised by the book of the same name written by Janine Benyus • Biomimicry is a method of solving problems that uses natural processes and systems as a source of knowledge and inspiration. • It involves nature as model, measure and mentor. • Geomimicry is similar to biomimicry but models geological rather than biological processes. The theory behind biomimicry is that natural processes and systems have evolved over several billion years through a process of research and development commonly referred to as evolution. A reoccurring theme in natural systems is the cyclical flow of matter in such a way that there is no waste of matter and very little of energy. Geomimicry is a natural extension of biomimicry and applies to geological rather than living processes We can learn from nature about how we should construct roads

29. Pervious Concrete Pavement - Addressing the Issues Pervious pavement is a unique and effective means of addressing environmental issues Image source: http://www.perviouspavement.org/

30. TecEco Permecocrete - Thinking About Water and Roads CO2 CO2 CO2 CO2 CO2 CO2 Pavements are not just for vehicles. They must do much more Cooling Evaporation Sequestration Moisture retention Cleansing microbial activity and oxygenation The substrate must be properly designed Optional groundwater recharge Optional impervious layer, underground drainage and storage. Dual water supply or parks etc. only.

31. Holistic Roads for the Future In Australia we run many duplicate services down each side of a road. Given the high cost of installing infrastructure it would be smarter to adopt a system whereby services run down the middle of a road down what amount to giant box culverts. Conventional bitumen or concrete footpath pavement Pervious Eco-Cement concrete pavement (Permecocrete) surface using recycled aggregates Pervious gravel under for collection, cleansing and storage of water Services to either side of the road. All in same trench of conduit Service conduit down middle of road Foamed Eco-Cement concrete root redirectors and pavement protectors. Roots will grow away from the foamed concrete because of its general alkalinity. It will also give to some extent preventing surface pavement cracking. Collection drains to transport drain or pipe in service conduit at intervals Impermeable layer (concrete or plastic liner) angling for main flow towards collection drains Possible leakage to street trees and underground aquifers Its time for a road re think!

32. TecEco Eco-Cement Permecocrete - Mimicking Nature • Permecocrete is made with Eco-Cements that set by absorbing CO2 and can use recycled aggregates. It does not get any greener! • Freedom from water restrictions – forever! • Pure fresh water from your own block. • Filtration through Permecocrete and water feature in garden will keep water pure and fresh. • Cooler house and garden (cycle under slab for house cooling/heating option). • Lower infrastructure costs for local council. Water featurekeeps water clean All rainwater redirected to pavement filter. Permecocrete pervious pavement Pump Water storage e.g. under drive

33. Placing Pervious Pavement Source: www.percocrete.com

34. Finishing Pervious Pavement Source: www.percocrete.com

35. Laying Pervious Pavement Source: www.percocrete.com

36. Cross Section Pervious Pavement Source: www.percocrete.com

37. TecEco Permecocrete • TecEco Eco-Cement Permecocrete concrete pavement technology • Is a unique and effective means to address important environmental issues and support sustainable growth. • Environmental Advantages • Slows down the rate of transport to rivers and streams • purifying water • replenishing natural aquifers. • Reducing salinity • Eco-Cement Pervious concrete sequesters carbon dioxide • Non Environmental Advantages • Safer for traffic • Improved acoustic properties • Reduces building maintenance • Cooler suburbs • Reduced drainage infrastructure costs • Reduces the need for culverts, pies drains, retention ponds, swales, and other storm water management devices. • Less watering of street trees

38. Environmental Advantages • Reduced volume and rate of runoff • Pervious pavement would allow the replenishment of aquifers and reduced the cost of infrastructure to carry water out to sea as the volume and rate of flow would be less. Not as many pollutants, rubbish and debris would be transported reducing waterway pollution. • Cleaner water - less pollution • A pervious pavement with integral bacteria would improve water quality entering aquifers, streams and rivers. The critical "first flush" of pollutants would be sent rapidly into the cross-section where constantly available sources of bacteria and microbes exist and have sufficient air exchange capability to maintain themselves and perform their cleaning functions. Pervious pavements could act as both pavements and bio-filters at the same time. • Replenish aquifers or provide water • Reducing salinity by replenishment with fresh water. • Permecocretes are also carbon sinks.

39. Non Environmental Advantages • Pervious pavements do not collect puddles of water making it safer for traffic • Pervious pavements are quieter as the absorb sound • Pervious pavement prevent the ground drying out under building cracking them. • Pervious pavements made with TecEco Eco-Cements are more durable • Cities with pervious pavement are cooler • They can transpire naturally (loosing latent heat of evaporation) • Eco-Cement Permecocrete concrete pavement has a lighter albido • Given economies of scale Tec-Eco Permecocrete pavement should cost less • Less infrastructure • Reduced need for culverts, pipes, retention ponds, swales, and other stormwater management devices

40. Hot City Syndrome and Pervious Pavement • Ever walked up a pebble beach on a hot sunny day? The heat held by the stones can be unbearable! It’s the same in large cities. There are so many materials with high specific heat that during hot sunny weather and with no natural transpiration, due to the fact that we have paved all the ground, large cities just get hotter and hotter. • As architects, engineers and designers of cities we need to come to grips with the macro impacts of the materials we use. Hot city syndrome is one of a number of man made phenomena that the use of pervious Eco-Cement pavements will reduce. The solution is to let the ground breathe and pervious pavements do this. Evaporation after all is still the principle behind many cooling systems – so why do we pave the ground and prevent moisture entering or exiting?

41. Collecting Rain Water Using Pervious Pavement Solving the Water Problem • An unknown but huge quantity of water is drained away to sea taking with it polluting substances and articles every time it rains on our cities. • This rapid drainage of rain requires a high cost of investment in much larger drains than the original natural drainage replaced because water no longer percolates through natural vegetation and obstacles. • In urban and some agricultural areas water gets to the sea in hours not days! • This water could be collected by permeable roads also acting as giant bio filters, subterranean reservoirs (the city of Alexandria had huge underground cisterns over 2000 years ago) and collection and redistribution network. • An essential component of this paradigm is pervious pavement.

42. The Clogging Myth - Cleaning Pervious Pavement Those who remain sceptics please also note that it is better to have pollution collected from a pervious pavement by machinery than pollute our coastal waterways Frimokar Australia high pressure jet and suction cleaning in action The experience of many engineers is that with relatively minor control and maintenance clogging will not reduce the infiltration rate below a design rate within the lifecycle of the pavement. Like any other kind of surface, pervious pavements should be cleaned periodically to remove debris and water under pressure combined with suction is most effective.

43. Making Pervious Pavement • Ideally a pervious pavement should be made with mono-graded stone aggregates and a binder and be similar to asphalt or concrete to handle and install. • In cold areas it is important that the pavement should not trap water otherwise in winter the water would freeze and cause cracking. • It is also important to detail a permeable structural base and sub base for the pavement that has a high void ratio as this acts as a reservoir, and provide underground drainage as required. Comparing Concrete Pervious Pavements to Asphalt

44. Salinity • Increasing salinity is one of the most significant environmental problems facing Australia. • While salt is naturally present in many of our landscapes, European farming practices which replaced native vegetation with shallow-rooted crops and pastures have caused a marked increase in the expression of salinity in our land and water resources. • Rising groundwater levels, caused by these farming practices, are bringing with them dissolved salts which were stored in the ground for millennia. • Salt is being transported to the root-zones of remnant vegetation, crops, pastures, and directly into our wetlands, streams and river systems. The rising water tables are also affecting our rural infrastructure including buildings, roads, pipes and underground cables. • Salinity and rising water tables incur significant and costly impacts. • According to the Australian National Action plan (http://www.napswq.gov.au/publications/salinity.html#how) and CSIRO web sites there are two main causes of salinity • irrigation salinity • dryland salinity • Caused by clearing • Caused by evaporation

45. Irrigation Salinity • According to the Australian National Action plan website at http://www.napswq.gov.au/publications/salinity.html# how salinity occurs through irrigation is because water soaks through the soil area where the plant roots grow, adding to the existing water. The additional irrigation water causes the underground water-table to rise, bringing salt to the surface. When the irrigated area dries and the underground water-table recedes, salt is left on the surface soil. Each time the area is irrigated this salinity process is repeated. • The government website quoted above fails to state the obvious which is that: • Every time water percolates through rocks and soil it picks up more salts. In the Murray Darling system a lot of irrigation water returns on the surface and underground to the river and is used again for irrigation, exacerbating the problem • The sequence forestry-agriculture-irrigation-salinity-aridity has destroyed many civilisations – will ours be next? Figure from the Australian National Action plan website at http://www.napswq.gov.au/publications/salinity.html#how

46. Dryland Salinity – Caused by Clearing • According to the Australian National Action plan website at http://www.napswq.gov.au/publications/salinity.html#howDryland salinity is caused when the rising water-table brings natural salts in the soil to the surface. • The salt remains in the soil and becomes progressively concentrated as the water evaporates or is used by plants. • One of the main causes for rising water-tables is the removal of deep rooted plants, perennial trees, shrubs and grasses and their replacement by annual crops and pastures that do not use as much water. Figures from the Australian National Action plan website at http://www.napswq.gov.au/publications/salinity.html#how

47. Dryland Salinity – Caused by Evaporation • Salinity also also develops as excess water moves to and collects in poorly drained discharge zones. The buildup of excess water brings dissolved salts to the surface where evaporation concentrates them. Figure modified from the Manitoba Agriculture Web Site www.gov.mb.ca/.../soilwater/soil/fbe01s06.html

48. Salinity, Agricultural Practices and Pervious Pavement Native tree belts • Salinity can be rectified by a combination of: • Deep drainage. • Mulching to increase humidity at ground level and reduce evaporative loss. • Planting deep rooted salt tolerant species and leaving native belts that reduce the overall rate of evapotranspiration of the fresh water lens on top of ground water. • Pervious rather than sealed surfaces (TecEco permecocrete pervious pavement). • Allowing capture of fresh water rather than run off. • Maximising capture and use of fresh water and minimising irrigation water. • Replenishing aquifers with fresh rain water rather than recycled water through irrigation. Deep rooted salt tolerent species (The PundaZoie company) Salinity in untreated areas Salinity in untreated areas TecEco permecocrete roads Contoured swales Deep drains Fresh water Salty water

49. How Our Theories Differ on Salinity • Many websites including the CSIRO and Australian government website on salinity when discussing salinity that is not clearly related to irrigation and the re-use of water seem to think that the problem relates to reduced evapotranspiration with agriculture and rising water tables that bring “ancient” salts to the surface. • We think this analysis wrong. When land is cleared natural mulches and soil humus that retain water and reduce evaporation and rate of run off at the surface of soils are removed. • As a consequence what then happens is that fresh water does not enter the water table when it rains. It runs off into our rivers. According to the water dynamic discussed above it also picks up salt and pollution. Gradually during dry periods the fresh water lens on top of our aquifers is used up and the saltier water underneath remains. • Reused irrigation water brings with it the salt it has picked up along the way.

50. TecEco Eco-Cement Pervious Pavement Permecocrete Allow many mega litres of good fresh water to become contaminated by the pollutants on our streets and pollute coastal waterways Permecocrete Or Capture and cleanse the water for our use? TecEco have now perfected pervious pavements that can be made out of mono-graded recycled aggregates and other wastes and that sequester CO2.