Additions .1.  is about the effect of pore pressure within the core. That is the pressure of water between  particles within the submerged core. This pressure, (at least at the interface of the core with the reservoir water) is equal to the outside water pressure. It is hydrostatic equilibrium.

I will explain to you as follows: The pore pressure is 62.5 lbs. per each foot of depth, equal to the outside water pressure. (When you go down 1 ft. it is 62.5 lbs. per sq. ft., at 2 ft. depth it is 125 lbs. per sq. ft. and so on adding 62.5 lbs. per sq. ft. for every additional ft. of depth).

There are 2 forces: one is downward weight from the top and the other upward pore pressure from the bottom. When you deconstruct the dam, the weight from top will become increasingly less, until the weight from top will be less than the pore pressure below. It will cause the upper core material to become weight less and virtually float  (that is behave like quicksand) and the core/dam will collapse catastrophically. I will need to spend more time and effort to bring this additional issue.

Seeing that I have already shown in item 5. of my additional comments that the dam will collapse catastrophically because the % water in the core makes it above the plastic limit (you can think of the nature of potters clay as an example that yields to the lightest outside pressure). So, I left this issue out. It is needless, I thought, at this time.

Addition 2.  Is about (para 2.4 preparation and review in my letter to BOR dated Nov 18, 2011): that the specialization of the person who prepared the deconstruction chapter of the EIS/EIR being a concrete specialist and not an earth dam specialist. Also the one who reviewed it, is a hydrologist. The BOR response to me says that geotechnical engineers were involved at every stage of the EIS/EIR. If so, their names are not in the important EIS/EIR but these names are in the later less important place of answering me. It does not make sense to me. The reviewer can only review the quantity of flood considered in the chapter on deconstruction, but not the aspects of an earth dam. But I thought it is a minor issue at this time.

Addition 3.  Is about my cross section drawing of the earth dam. The BOR claims it is not correct. I said in my original comment that it is an earth dam’s  general cross section. The actual cross section is not in the EIS/EIR. The BOR does not include it in their response to me. True, it would have a cutoff to the foundation rock level which is not in my sketch. In any case the cutoff affects only the uplift from below and will not negate the issues that I raised which are all about matters over ground. The BOR can give the actual embankment cross section. The BOR can give it now. In any case the EIS/EIR gives a description, from which I made out an over ground general section to argue my points.

Addition 4.  Is about my describing the core being made ‘stone hard’.  I said so for the benefit of lay people such as the county supervisors and county counsel who would read it that it is very hard. The BOR makes it a big issue in their response. I should have just said ‘hard’. And now it is saturated with water and soft. Does the BOR deny that? My  comments still are relevant

Addition 5.  Is about my suggesting to the BOR that, (since the dam cannot be safely removed), their engineers can review the topography of the 4 dams and reservoirs, consider the data and innovate a new hydro-system passage to provide the bulk of the juveniles and the adult spawners a safe passage. I said that “this is an engineering problem and demands an engineering solution. The dams are to stay …… and the salmon to recover. I believe, it is possible”. The BOR response says that this is not a decision for the Reclamation design team. I would only say that it is a pity  It should be a challenge.

Sincerely,

Stephen