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Oroville Dam Leak - Topo Map & DWR's "natural spring" theory - Water must flow uphill from abutment

Using elevation markers on the clear water leakage causing green vegetation growth reveals that any proposed "natural spring" theory requires uphill water flow. DWR engineer's statement that the water is from "a natural spring" cannot explain how the water climbs in elevation along the backside of the dam. The topography map places more difficulty in this theory as the 700 ft elevation level "retracts" from the leaking area (further into the dam to the core). Therefore, any "natural spring" would be flowing DOWN the original canyon rock abutment as the Zone 3 Shell, where the leakage is flowing through, is designed to be non-pervious (which means water percolates downward through - as it is designed). Since there is NO topography higher and to the left of the greening wet area ANY clear water would have to FLOW UPWARD to get to the greening elevation.

The only DOWNWARD flow of water to the greening wet area must be from the reservoir (i.e. "through the dam" seepage). The reservoir has been at record levels for a prolonged period. So too has the greening been at its greatest. The horizontal "greening" has a strong inference to a horizontal seam source or sources to this clear water flow. DWR absolutely must respond in identifying the risk to this situation. The public should know that DWR does not know the source to this water flow as they asked FERC to relocate a test drill well near the embankment to figure this out - in 2016. DWR has no standing in saying that this is a "natural spring". In fact, the dam leakage could give water readings in the abutment's highly fractured rock as if there were a "spring" - but from DOWNWARD flow from the core.

At the DWR town hall Q&A, the DWR engineer denied that the water flow was through the dam ("it is not going through the dam"). The evidence infers otherwise.

DWR engineer - at DWR town hall Apr 27 2017 Q&A stated "a natural spring" was water source - elevation data proves this to be incorrect - water must flow upwards

Dam topography map of the inner canyon wall abutment re-inforces the error of stating "a natural spring" - elevation & location of the topography reveals water must flow upwards. Best fit is seepage "through the dam". DWR engineer denied "seepage through the dam".

Good data gathering.

It would be good if there was some sort of survey of similar existing problems and (if any) solutions.

I would just guess that these dams are made watertight with a layer or layers of clay, and that earth fill would be put on top of that. If so, I wonder if that means that the clay layer has somehow been breached. If that is true, then what are the causes and what would the cures be? It almost seems as if a significant portion of the dam would need to be rebuilt at the top (eg above 780 feet) to fix the immediate problem. The pentultimate question would be how bad the problem actually is and if it is sufficient to monitor the problem to ensure that it does not get any worse.

In Santa Clara Valley there is Lexington Reservoir which is 195 ft. high. It has a seepage pond at the downstream toe, since the 1950’s. The seepage is enough to sustain some flow of the downstream creek through the midsummer months (at least, most of the time)n. Some seepage is normal though evidently not at such a high level as Oroville has. I have seen cross section diagrams on the net that have diagonal “seepage lines” through earth dams.

I am just an onlooker, so no expert info here.

Gallery Tunnels in Oroville Dam - & DWR's "natural spring" theory - Where's the water?

Carved in the rock in the canyon walls of Oroville dam are access tunnels referred to as "Galleries". They are encased in reinforced concrete and backset into grooves along the abutment rock wall. The Gallery tunnels along the left and right abutments of the dam are called "Grout Galleries" as they follow the grout sealed rock boundaries of the canyon.

Since DWR believes that "a natural spring" may be the cause of the green wet area dam face leakage, even though there are difficulties with the "uphill flow" physics :-) , DWR could investigate for any small moisture spots within the tunnels. A "natural spring" in the hillside could possibly create minor "wet spots" or "seepage" in the concrete, in the location of a purported "spring". The Grout Gallery Tunnel routes downward along the full hillside from 820ft in elevation to the bottom of the dam at the concrete core block. Any "seam" in the weathered rock of the hillside that is producing waterflow in a "natural spring" could elevate the water density surrounding the tunnel.

Dam Safety Inspection reports have documented areas of seepage within these tunnels, but not in the mid to upper elevations. The greatest "seepage" flow is deep in the core block at a seam of section joints 12-13 in the "bypass Gallery" (another connecting tunnel in the core block). This flow is significant, but normal under the high water pressures in the concrete block at the bottom of the reservoir lake level (but within the center of the dam). Sump pumps drain all of the "seepage" inside the concrete core block into a drain pipe that dumps it into one of the two outlet "diversion" tunnels the Hyatt power plant uses in exhausting turbine flow(s).

Yet the Safety Inspection reports do not mention any "seepage" of note in the upper elevations of the Grout Gallery Tunnel in the Left Hillside. Perhaps there is a "clue" if there were a "natural spring". Where's the water? AND- this has to be special water in that it may need an ability to "flow uphill" :-) .

Strong Seepage Water Flow deep inside the dam (normal) within the large concrete "core block" the main earthen clay core is built upon. Sump pumps drain this water into Diversion Tunnel 2 in the Hyatt outlet tunnels.

Original Archive document describing the Left and Right Grout Gallery Tunnels - re-inforced concrete tunnels along the rock abutment canyon walls of the dam. Entrance to the Left gallery tunnel is at/near 820ft.

Entrance to Left Grout Gallery Tunnel - goes 780ft down to the concrete core block at the base of the center of the dam - Fans at this entrance circulate fresh air to the lower tunnels below