The Entry Point & Final Route For The Cishan Diversion Channel Into Agongdian Reservoir (阿公店 水庫)

Yesterday I travelled down to the back of Agongdian reservoir again in search of the diversion channel's entry point into the reservoir. Since previous efforts exploring both the Wan-lai and Zhuo-shui feed rivers had turned up nothing, I had began to suspect that I had been right the first time....

In November 2012 I had found what I believed to be the entry point (shown above) into the reservoir for the diversion channel. However, I was subsequently told by someone in the Yanchao office that it was not. I was suspicious for three reasons: the location was approximately consistent with where I would expect to find the entry point - to the back end (east) of the reservoir and slightly to the south; the volume of water spilling out of it was consistent with the volume I had previously seen leaving the control gate in Neimen district; and the concrete dressing for the channel looked about the right age (according to the leaflet provided to tourists, the diversion channel and other remedial facilities at Agongdian reservoir were completed in 2006).

However, in the Yanchao office there was a wall-mounted chart indicating that the diversion channel entered the Zhuo-shui river - which was much further to the south. That, and the dismissal of my previous conjecture by the chap from the Yanchao office gave me some reason to doubt and to look elsewhere - which I did. I spent almost a whole day (11th December 2012) searching the length and breadth of the Wan-lai and Zhuo-shui rivers looking in vain for signs of an entry point. Last week I went looking around the Zhuo-shui river again, and again in vain. This made me suspect that I had been right the first time. So yesterday morning, I drove back down to look around some more.

Almost a full year later since my first visit to this channel, it's banks are now already overgrown with bushes. This time I poked around a bit more. Here is the entry point for a small stream diametrically opposite to the channel...

Together the two water courses enter into this triangular pen, with the channel entering to the right and the little stream entering to the left...

Atop the bank above this pen, and hidden amongst the reeds and bushes, I found confirmation that I had been right the first time and that the channel was indeed the diversion channel from the Neimen control gate...

This side of the little post reads "Agongdian reservoir".

This side reads something like "left break 31", which I take to be the 31st left "turn" on the route of the diversion channel down from the Neimen control gate. The kinks in the channel must have been numbered in this way in order to verify locations on the plan drawings for future repairs. It's likely I'm going to find many more of these little posts later when I go following the diversion channel upstream back up into the Tianliao "badlands".

This side reads something like "south water bureau". The first character has been broken, but I'm quite sure it's the character for "south" ("南").

This side gives the date: "97" refers to the year 2008, and "10" must be October. That date surely refers to the completion of at least this particular section of the diversion channel, if not the whole thing. If that's so, then a completion date of October 2008 would contradict my previous information putting the completion of remedial works for Agongdian reservoir at the end of 2006.

Having apparently confirmed that this was in fact the diversion channel, there were only two problems left to solve: one was to follow the stream issuing out of the triangular pen to check its final entry point into the reservoir; the other was to follow the diversion channel upstream and try to document at least some of its' route through Tianliao and Neimen districts. Heading back out onto the "main" back road I followed another road some distance off that was headed in the same approximate direction (northward) as the stream issuing out of the triangular pen. This choice of road proved correct and I soon came to a bridge over the stream. The shot below is oriented approximately south-east...

The next shot, again from the little bridge, is oriented approximately north-west...

I followed the road up some distance without so much as catching a glance at the stream again and so I eventually doubled back on myself to pursue a detour down an adjacent little farmer's road off to the west - and although I eventually found the stream again, some farmers told me there was no road through, which was probably true because most farm roads end up as cul-de-sacs surrounded by guava trees. Instead the farmer suggested me to go back to the main road and continue northward but to turn left at the new temple under construction. I did this and found another cul-de-sac on top of a ridge, but it did at least afford another view of the stream to confirm that I hadn't lost it...

Following an adjacent little farmers' road down this ridge, I came to a shoreline where the stream meandered in from the south-west...

... and flowed past my point on the shore and out of view again to the north-east...

By this point, the stream had broadened considerably and it was now so far to the north of the diversion channel's entry pen that I was now reasonably sure I knew what was going on; there is no way a broad stream like that is going to enter the reservoir via an underground passage, as I had previously wondered. No, what was happening was that the engineers had used (and undoubtedly augmented) an existing, minor water course to transport water from the diversion channel into the strange, backward-reaching, brachial fracture of the reservoir to the east and north...

As I turned to head back to the main road I noticed another little marker post with the characters for "Agongdian reservoir" inscribed. This post looked somewhat older as the characters lacked the red paint featured on the one I had previously seen, though I wonder whether that may have been the result of repeated flooding of the stream during typhoon seasons.

A view of the stream heading around another bend further to the north...

Following the road further and further north meant that Dagangshan hill loomed closer and closer and that also meant that I would soon see the reservoir's rear exit point toward the newly constructed adjunct spillway. In this shot below, Dagangshan hill is the diagonal slope in the background, with a similar downward slope mirrored by the waterline below as it passes on its way to the easternmost extremity where it is blocked by an artificial weir before reaching the new spillway. The slope in the bed of the reservoir is given away by the waterline along the concrete steps on which the fishermen stand...

Further on up the road, atop a bridge over this narrow stretch of the reservoir, looking back southward toward the steps preceding the passage to the rear spillway (notice the private residence in the background)...

Turning westward atop the bridge, here is a view of where the broad stream fed by the diversion channel (to the left) finally enters into the reservoir's north-eastern channel (through the gap between the two opposing spurs to the right)...

After satisfying myself on this point, I decided to have a quick look around into Tianliao district for signs of the diversion channel. However, I quickly ran out of time and decided to leave that task for another trip at some future point.