From: --erased--

Date: Thursday, November 5, 2009 2:09 am

Subject: Disconnecting rivers from seawater mouths



Mr. Stefan Scheuer

Mr. Jamie Pittock

Mr. Josselin Rouillard

International Rivers

2150 Allston Way, Suite 300

Berkeley, CA 94704-1378




Dear Sirs,

I recently became aware of your publications regarding the preservation of our rivers. Some time ago, I was taken by a remark in a publication of National Geographic ( ) that thedisconnecting of rivers from their seawater mouth allows (in certain cases) several benefits to the ecology of the river. Being also convinced of the benefits the disconnectingof a river from the seawater mouth regarding pollution control (from ships and other sources), I would like to notify you of this idea in the intrest of the protection of our waters. Note that the pollution reduction would btw be a result of the fact that the water distrubution companies will have to put down more extensive quality levels, perform more checkups and fine any trespassers (shoreline industry and ships). In addition, as some form of barrier is then placed, checkup of the ships regarding the pollution from the ships engines can be better monitored. It would btw be most advisable to also restrict access to any ship that does not use either wind energy (eg from sails or energy harvesters), or run its engine on an emissionles fuel (such as oxyhydrogen, hydrogen, liquid nitrogen, ...). Information on this can be found at, and 

An image I made showing how such a river diversion can be made is available at 

Note that, as too the image explicitly shows, the redirection is not complete in that ships and fish (comparable to a ) can still cross the barrier. Indeed perhaps that some organisms living in brackish water may have trouble crossing the barrier, but it is likely that such diversion projects will only be set up in suitable areas (without many such organisms). In addition, the preservation we will be able to perform using this technique (if correctly done), in areas where other species exist that require brakish water/cross the barrier would allow to save much more (freshwater) species than what would be lost when placing the barrier at less suitable locations (also because species in brakish water only compose a very small percentage of the worldwide species).

I am certain that this idea, besides being beneficial to the Murray river, can also be implemented into other streams with comparable benefits, hereby globally improving the quality of our waters and increase its biodiversity to acceptable levels. Also, as global warming is on the rise, water is more and more increasing in cost, and may make certain projects economically feasible (at least when seeing the projects as long-term renewable resources).

Thanks in advance,

Yours sincerely,


On Sat, Nov 7, 2009 at 7:11 AM, James Pittock <> wrote:

Dear --erased--,

Thank you for your note and ideas on disconnecting rivers.

As an environmental advocate, I actually want rivers connected to the sea. Important ecological processes occur at the interface of freshwater and seawater, such as sustaining particular fish species, supplying nutrients to near shore marine ecosystems, and creating mudflats, sandbanks, beaches and delta lands that are particularly productive ecosystems. Barriers, such as those near the mouth of the River Murray (and despite inbuilt fish passes), invariably cause substantial environmental degredation and incur great costs.

While harder to achieve than a simple engineering fix, I advocate better river basin governance and water management to meet societal needs for water while also keeping rivers connected to the sea.

Yours sincerely

Jamie Pittock

--------- Forwarded message ----------

From: --erased--

Date: Sun, Nov 8, 2009 at 1:05 PM

Subject: Re: Disconnecting rivers from seawater mouths

To: James Pittock <>,,

Dear Sir,

Thank you for your message of 7 november 2009.

In the this message, you state that you still want rivers to be connected to the sea as they are areas which make up a unique ecosystem. However, as I already stated in my previous message, I do not dispute the fact that some biodiversity will be lost, but I argue that the degree in which this will occur will be far less great than the loss which would occur if the rivers are not disconnected from the seawater.

This may be a strange statement, but it can be explained as the availability of fresh/potable water for the people living in the area will be far smaller. This means that, in order to create enough potable/fresh water, wells need to be dug or seawater is desalinated; rainwater and melting water is another possibility but is less practiced and is also not possible in certain areas. These constructions (which are allot more expensive than simply damming a river and adding a fish pass) thus need to be set up and require a great deal of electricity (to keep the pumps, ... going). Aldough ideally this power may be generated from renewable sources, this is often not the case, and extensive carbondioxide emissions need to be calculated in.

This increase in greenhouse gases then fuels global warming, which will kill off much more organisms, then what will be lost by restricting passage to (certain) freshwater rivers (some rivers should still be excluded depending on regional circumstances). Note that greenhouse gases are offcourse also emitted from other sources aswell and thus environmental organisations (such as yours) should conduct more extensive research to make sure that accurate records of the biodiversity losses and gains for these projects are made and compared objectively (especially as no such readings are already available). However, given that 30% of all natural species will be lost by 2050 (the species inhabiting the brakish water zones only being a very small portion of these; eg less than 0,5%), I think the losses are justified, aldough again, more research by your organisations regarding this is required.

As such, at the moment (and for a long time to come), we must implement the most suitable water supply system, in order to reduce energy requirements (an thus greenhouse emissions) and to some degree also to decrease human suffering due to water shortage (already present in certain developing countries and increasing due to global warming; see

I am hoping that your organisations may perform the required research and (depending on the results) support my idea.

Thanks in advance,


PS: Also note that, apart from using a mere barrier to make the disconnect, perhaps that some other systems (eg a lock system where the first barrier is opened and seawater (+organisms) is let in, and then the first barrier is locked and the second barrier is opened, closed and seawater pumped off (due to the fact that freshwater will rise to the top, and seawater to the bottom)) may be used. This latter system (aswell as perhaps other systems) may allow more organisms to pass rather than a mere low barrier. These system types thus all need to be looked at by your organisations aswell to decrease the (already limited) loss of species in these zones.