Water worse then better

Last week we had a new water tank fitted that was bigger and had a safety switch to turn off the pump before it could run dry. We have been having a bit of a nightmare with it. Or not exactly with the tank, but because of the change to the flow rate through the system - mainly due to a filter being added. When the filter is new in and clean it can just cope with the flow, but as soon as it starts to get a bit dirty the spring starts backing up in the channel causing a muddy pond (at A in the diagram) which then overflowed down the bank. As soon as this happened the filter became pretty much entirely blocked as the water got muddier. We were also concerned that the wall holding the spring back was going to collapse on the water but breaking the whole system. We ended up cleaning the filter several times a day to keep the water flowing. We could have removed the filter from the system, but we didn't want the new tank to fill with mud (although it does have a tap to allow cleaning) and we didn't want to drink such muddy water.
This diagram shows the system from above and then from the side. Sorry if it is not clear - but it will help us remember in the future what we have done!

We have had to made an emergency improvement to the system so that the water from the source can overflow safely without creating a muddy pond. While doing the modifications we discovered the little flows of water shown as thinner blue lines which flow out of the bank and were carrying mud in to the water. The new solution excludes these too and allows them to flow safely round the tank.

We added a small dam (shown as a grey curve) to collect the water in to some drain pipe. The drain pipe has a T junction in it and the pipe in to the filter is connected to the end of the drain pipe (that bit was a bit tricky - there don't seem to be 80mm to 25mm connectors but we drilled a hole in a drain pipe cap for the pipe to go through). When the water can't flow through the filter fast enough it backs up the drain pipe (no mud) and flows down a pipe attached to the T junction.

The diagram makes it look all lovely and neat, actually it is a big mud swamp due to the water having been going everywhere it shouldn't for a while and the ground is pretty uneven too. We hope it will dry out now it is mostly in pipe.

Close up of the pipe section

There is a good youtube video here about how to capture a spring. We might do a more thorough and buried in the hillside solution sometime in the (far and distant) future. We still need to improve the covering of this solution as the spring before the pipe is just covered in pieces of slate which could let runoff water in.

Another interesting thing this video mentions is ram pumps - they use only the power of the water to pump a portion of that water up hill (ie no electricity needed). Possibly an interesting solution to our need to get drinking water for the animals (and for the potager) higher up the land. Doug calculated the spring provides 21,600l of water a day. We only use a few hundred so we need to find more uses for it!!
Doug did look in to hydro electricity, but apparently we would generate something like 86 watts... so not so useful.