Precipitation on impermeable surfaces in cities frequently creates a surge in runoff during storms that is difficult to capture or divert. At the same time, some of these same cities are located in areas of water shortage. Not long ago, during a discussion about water supply and drought (for example, in California), the idea of diverting storm water runoff into groundwater recharge came up.
I am not a civil engineer. I would be interested in learning about the feasibility of this idea and whether there are any designs or prototypes for this. .
In many municipal areas, combined sewage outfalls (CSOs) are being replaced by underground storage tanks and tunnels for storm water runoff. The surge in surface water is retained and held, then pumped back out later, treated (it has a significant coliform count), and discharged. What if the treated storm water were pumped into an injection well or allowed to percolate through a sand channel to recharge the aquifer instead of discharged into waterways?
There are obviously a lot of questions to be answered. Would the volume of water retained be worth it, would it be too expensive, would access to groundwater create an opportunity for inadvertent contamination from the surface, is there a mismatch between where the water falls and where the aquifers lie and therefore excessive costs for transport, etc.
I am aware of a few communities that have used direct connections with the aquifer to recharge groundwater with surging stream flow during precipitation events.
Hello Tee. The Orange County Water District in California maintains one of the nations most extensive aquifer recharge programs. Storm water that would be lost to the ocean is captured and used to replenish groundwater aquifers http://www.ocwd.com/ProgramsProjects/GroundwaterRecharge.aspx
Technically yes, but practically not done in current flood or storm control design and management.
Floods and their impacts on waterways, society, and the economy have been investigated intensively worldwide. But, flood impacts on regional groundwater (especially shallow aquifers) and their quality are not well documented. We have a manuscript currently under review that looked at impacts of a recent major flood in Northeast China on the regional groundwater recharge and chemistry. If accepted, I would be happy to post the article on researchgate.
Yes, it is quite used and feasible in many arid regions. The main concern is the quality of the storm runoff that can be used for groundwater recharge. In many events, the aquifer formation can enhance naturally the water quality during infiltration process.
Yes, it is quite used and feasible in many arid regions. The main concern is the quality of the storm runoff that can be used for groundwater recharge. In many events, the aquifer formation can enhance naturally the water quality during infiltration process.
Hello Tee. The Orange County Water District in California maintains one of the nations most extensive aquifer recharge programs. Storm water that would be lost to the ocean is captured and used to replenish groundwater aquifers http://www.ocwd.com/ProgramsProjects/GroundwaterRecharge.aspx
It is possible. In New Delhi some organizations are promoting it (like Centre for Science and Environment). Only caution is, proper natural filtration should be in place (like slow sand filter or similar). Direct recharge is not advisable.
Yes groundwater recharge is the natural process. It can be assisted by providing areas of infiltration where water can be routed, however, the recharge rate capacity is dependent upon soil and geology and surface characteristics. Some type of surface storage must exist because the flows during a storm are likely going to exceed the capacity to recharge so a lot of the water will run off.
Thanks to all. My question was specific to engineered recharge systems using treated water recovered from retained storm (not flood) water. I am aware that surface runoff is not of acceptable quality for direct recharge bypassing percolation and filtering. The Orange County model sounds interesting and I may try to arrange a visit on my next trip to LA.
I am mulling over topics for the follow-up to my book Health and Sustainability (Oxford, 2015). Thinking about health and engineered systems, so-called "artificial ecosystems".
Hello Tee,
Hope all is well . Give me a call and we can discuss in more detail.202 362 3076
Joe
Good idea. I calculated that I can store 15,000 gallons of water a year from the small annual rainfall in San Diego by adding cisterns. My neighbor has already started.
Qualitatively this is certainly possible and is occurring e,g, with so-called Low Impact Development (LID) best management practices (BMPs). The modern emphasis on onsite control of stormwater is premised on infiltration using pervious pavements, raingardens, bioretention etc. The challenge is always quantitative - How Much recharge (and for your question, usable recharge) can this produce in a particular system? ,How much "passive" attenuation of the mix of pollutants in stormwater is actually occurring through a stormwater recharge BMP and the recharge flowpath.
As an simple example, northern states are seeing a steady increase in chloride concentrations in stream baseflow attributable to the use of deicing salt. Very difficult to "remove" this from stormwater runoff, and once in groundwater difficult (and slow) to flush - even if you severely attenuated and targeted the use of all deicing chemicals.
Dear Tee Guidotti: Aquifers recharge is a possibility that was already studied for scarcity of water resources since many years ago, even particularly for municipal wastewater reuse after treatment. With respect to pluvial water in urban areas, the problem can be the pollution resulting from the washing of the streets and edifications that occurs in the beginning of the atmospheric precipitation, assuming that we have a separate system for sanitary sewerage and storm water drainage. In my opinion, old combined systems that still exist, particularly in the center of great towns, are obsolete. Also, geologic conditions and characteristics of the aquifer, topography for detention ponds natural or constructed, and soil permeability must be favorable. Some years ago, we studied very challenging situations of scarcity of water resources in Santiago Island, Cape Verde, but recharge of the existing underground aquifers was not the first option.
I guess that it is a very important and pertinent question, too complicated because of the numerous parmeters that must be taken into account, either for the local geology or and mostly the intensity and nature of human activities.and their polluting impact on the ''urban aquifer''. We have also to consider the coastal areas where any increase of the water table level will genarate an increase of volumes of waters toawards the sea and the existing springs. it will be certainly a very intersting idea if it is part of a global management project with a multidisciplinary approach.
I guess that it is a very important and pertinent question, too complicated because of the numerous parmeters that must be taken into account, either for the local geology or and mostly the intensity and nature of human activities.and their polluting impact on the ''urban aquifer''. We have also to consider the coastal areas where any increase of the water table level will genarate an increase of volumes of waters toawards the sea and the existing springs. it will be certainly a very intersting idea if it is part of a global management project with a multidisciplinary approach.
I guess that it is a very important and pertinent question, too complicated because of the numerous parmeters that must be taken into account, either for the local geology or and mostly the intensity and nature of human activities.and their polluting impact on the ''urban aquifer''. We have also to consider the coastal areas where any increase of the water table level will genarate an increase of volumes of waters toawards the sea and the existing springs. it will be certainly a very intersting idea if it is part of a global management project with a multidisciplinary approach.
In South Africa we have been running some experiments and they seem to be working well, especially in the arid part of the country where evaporation rates are high and precipitation rates are low.
Some years ago in Finland I visited a rural area where local farmers were opposed to groundwater recharge strategies. They were of the opinion it would only contaminate their pristine water supplies.
So, it appears as if there are concerns in high-rainfall areas and acceptance on low rainfall areas.
On the whole, I think, topping up an aquifer is potentially a better route to follow providing appropriate water quality monitoring strategies are in place.
In South Africa we have been running some experiments and they seem to be working well, especially in the arid part of the country where evaporation rates are high and precipitation rates are low.
Some years ago in Finland I visited a rural area where local farmers were opposed to groundwater recharge strategies. They were of the opinion it would only contaminate their pristine water supplies.
So, it appears as if there are concerns in high-rainfall areas and acceptance on low rainfall areas.
On the whole, I think, topping up an aquifer is potentially a better route to follow providing appropriate water quality monitoring strategies are in place.
Dear Mr. Guidotti,
In Iran groundwater level withdrawal is an absolutely concerning problem. As an example in Rafsanjan valley groundwater level dropped from a 50m depth to about 300m. In my hometown, Mashhad, the maximum drop is about 70 meters in a 40 years period. I am writing drought management plan for urban areas in order to prevent groundwater level drop in Mashhad Valley for my master thesis. As an engineering solution I am working on this idea to manage storm water on impermeable surfaces in order to recharge groundwater resources and slow down the withdrawal. The problem is we haven't done this before in our country that much to use previous experiences and beside that we have lots of dust and soil on our pavements although the pavement is asphalt or something else. So the problem would be about filling the recharge wells.The other problem would be about the pollutions on the surfaces.
Beside that I am working on it to present optimized model as a solution. With a drought management point of view, it worth to invest on it in our city because we are facing serious problems because of groundwater level drop and it needs to be prevented as soon as possible.
I find your question very interesting and it is very useful also for me. An I thank to people who answer.
Best regards,
Farhad
Groundwater recharge has been a topic of discussion for a long time. In fact many of the aquifers in semi-arid zones are maintained by the infiltration produced in the dam reservoir systems.
Some of the interesting reflections given to this question are complementary and should add that you should always analyze several alternatives and choose higher benefit-cost and minimal environmental impact.
Bottom rack intake systems are used to collect the maximum quantity of water on ephemeral and torrential rivers with important sediments transport. Due to the fact that the bed load sediment transport passes over the racks, they have to operate under extreme conditions.
In the following link you can download an article that discusses these problems and the main design characteristics of these systems:
https://www.researchgate.net/profile/Luis_Castillo26
Recharging groundwater directly from diverted storm runoff is potentially dangerous because of introducing contamination into groundwater. The original question dealt with retained surface runoff from municipal storm sewer tunnels that would then be treated and injected into groundwater rather than discharged into waterways or the ocean. The ideal recharge mechanism, of course, is percolation (which also filters) but there is not enough permeable surface in urban areas to recharge local aquifers.
Dear Tee,
you're right with respect to injecting treated sewage into groundwater being a potential hazard. Your remark regarding the absence of impervious surfaces in urban areas can easily be overcome. Over the last decades a lot of development has taken place resulting in a wide range of pavement materials that allow runoff to infiltrate. It will ask for some planning and careful policy making (e.g. avoid parking lots and road with heavy trafic as infiltration areas). Furthermore citizens can be encouraged to drain the private areas in infiltration units. When you do a survey on the internet on the buzzword SUDS (Sustainable Urban Drainage Systems) you'll surly find a lot of detailed info and descriptions of case studies.
best regards
Francois Clemens
Injecting partially or untreated sewage should not be done because it will contaminate the aquifer, however injecting highly treated sewage (drinking water quality) into the aquifer is successfully practiced , as is done in Orange County California. It is done for groundwater recharge and also as a seawater intrusion barrier. Perculating partially treated sewage by land spreading is also done successfully in many locations including Los Angeles. It is called soil aquifer treatment. The geology provides a treatment medium and produces high quality water. That's also what mother nature does.
certainly, if surface runoff is excess, that can be diverted into under ground aquifer,
yes this may be some hypothetical ,surface runoff with some filter treatment, may be kept in the aquifer,there are possibility that this under ground water may reach to drought pron area!,
or directly linking with river if topography permits
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