iREACT Consulting and our partners Groundwater Dynamics (GWD) believe it can. In fact, we think it will allow the ideas to be migrated and implemented in urban areas as well.
Natural Floodplain Management (NFM) is an emerging solution that is gaining traction with communities and the Environment Agency in the UK and increasingly across the globe for a number of reasons aside from simply Slowing the Flow of impending flood events.
A natural approach to flood management, such as introducing beavers, repairing leaky dams, and restoring wooded areas and moorlands, has many aesthetic and environmental benefits as well.
We are certainly advocates of planting more trees, but in the short term, we are not going to see any reduction in flow rates from this activity until they reach a certain maturity. And we certainly cannot plant enough trees in suburbia to make any impact.
But rather than restricting the NFM solutions to being purely natural, why not consider a technology that mimics nature and enhances its capabilities?
EGRP (Energy-passive Groundwater Replenishment Pump) [now referred to as the equally catchy ECO90] is one such technology we are attempting to introduce into the NFM and SUDS (Sustainable Urban Drainage Systems) spaces.
Conceptually, it is a simple system which comprises a number of plastic rods being bored into the ground at various depths between 1.5m & 12m. The first stage is an ISO 22282-2 Geo-hydraulic infiltration test drilling exercise to ascertain the local Drainage Design Rate. Once this has been identified an engineering Drainage Design Statement is produced using industry standard software & detailing the half drain-down times within a 24 hour period for a chosen storm event (with an allowance for Climate Change). The system design is backed by GWD’s PI Insurance with warranties being signed off for Local Authorities by our engineering partners.
Unlike NFM, ECO90 solutions can be designed and measured to give exact absorption and therefore attenuation rates to slow the flow into downstream areas by taking the water below ground.
Mon 10th Feb 2014 at 4pm
Tues 11th Feb 2014 at 8am
Like NFM, ECO90 mimics nature and the structure of piles inserted into the soil act very similarly to that of the root structure of a mature tree. The key difference being that ECO90 can achieve these results in 12 weeks rather than the 12 years a mature tree would need to match these results.
Of course, like all solutions, it is not a panacea and will only work in the right geological areas, as we have discovered through numerous test bores at proposed sites, but where the conditions are right ECO90 has proven to be a great solution in dealing with surface water flooding. There are numerous case studies to show how this has worked in the sports arena where Groundwater Dynamics are working with some very happy ground staff at numerous high profile sports arenas across the UK.
NFM is an obvious fit for ECO90 in rural flood attenuation solutions but due to its unique attributes (no maintenance, management of pollution and low planning requirements) it is also ideal for urban SUDs solutions too.
It is being incorporated into natural solutions such as swales and soft landscaping for new developments. It can be installed under permeable paving & tarmac/concrete to increase the capacity of these solutions and it can be installed in conjunction with linear road drainage systems to amplify their discharge rates into the subsoil rather than the drainage network.
ECO90 reduces the impact on existing infrastructure because it is moving the surface water from the skies to underground aquifers and natural storage areas deep in the subsoil.
Imagine the benefits to a builder on a new site when he can obtain his SUDS licence by installing a small ECO90 Rain Garden in a small plot that can (with careful design) cope with the surface water for the whole development and without any connections to the main drainage network.
Consider designing a system for a supermarket or business park carpark capable of dealing with 100% of storm water at source without having to connect to public storm water drains or combined sewers & saving huge fees payable to the local water company.
Dream of hundreds of new NFM schemes with engineered absorption systems and the benefits that can bring to enabling the solution for deployment in suburbia.
Then think about the added benefits of an ECO90 system that actually returns surface water underground and, replenishes (recharges) groundwater supplies at source.
STRI Infiltration Test – rates improve by 5 to 17 times in clay loam soil type
Unlike NFM, ECO90 solutions can be designed and measured to give exact absorption and therefore attenuation rates to slow the flow into downstream areas by taking the water below ground.
Pictures taken by Groundsman at Edgbaston No1 Practise facility
Mon 10th Feb 2014 at 4pm
Tues 11th Feb 2014 at 8am
Like NFM, ECO90 mimics nature and the structure of piles inserted into the soil act very similarly to that of the root structure of a mature tree. The key difference being that ECO90 can achieve these results in 12 weeks rather than the 12 years a mature tree would need to match these results.
How it Works
Each ECO90 rod is installed 100mm to 750mm below surface level and it takes 12 weeks before the system begins to work. Water moves horizontally in poor draining sub-soil and the ECO90 acts like an elevator shaft taking water down to lower unsaturated levels where it finds its way into the soil strata via fissures which build up around the system.
Of course, like all solutions, it is not a panacea and will only work in the right geological areas, as we have discovered through numerous test bores at proposed sites, but where the conditions are right ECO90 has proven to be a great solution in dealing with surface water flooding. There are numerous case studies to show how this has worked in the sports arena where Groundwater Dynamics are working with some very happy ground staff at numerous high profile sports arenas across the UK.
NFM is an obvious fit for ECO90 in rural flood attenuation solutions but due to its unique attributes (no maintenance, management of pollution and low planning requirements) it is also ideal for urban SUDs solutions too.
It is being incorporated into natural solutions such as swales and soft landscaping for new developments. It can be installed under permeable paving & tarmac/concrete to increase the capacity of these solutions and it can be installed in conjunction with linear road drainage systems to amplify their discharge rates into the subsoil rather than the drainage network.
ECO90 reduces the impact on existing infrastructure because it is moving the surface water from the skies to underground aquifers and natural storage areas deep in the subsoil.
Indirect to Ground Infiltration
Each ECO90 device is first of all capped and then positioned at 300mm to 600mm below ground level with storm water entering the system laterally and not vertically. Where the ECO90 system is receiving storm water from roads and/or parking bays then a number of measures are taken to ensure that sufficient levels of treatment are designed into the SUDS design solution for example;- Baffle & Wier Gulleys
- Permavoid Bio-mat crate system
- Inbitex Bio Geo-textile
Imagine the benefits to a builder on a new site when he can obtain his SUDS licence by installing a small ECO90 Rain Garden in a small plot that can (with careful design) cope with the surface water for the whole development and without any connections to the main drainage network.
Consider designing a system for a supermarket or business park carpark capable of dealing with 100% of storm water at source without having to connect to public storm water drains or combined sewers & saving huge fees payable to the local water company.
Dream of hundreds of new NFM schemes with engineered absorption systems and the benefits that can bring to enabling the solution for deployment in suburbia.
Then think about the added benefits of an ECO90 system that actually returns surface water underground and, replenishes (recharges) groundwater supplies at source.
