A couple of thoughts:

It would be wise for the court to extend the claims filing period in the adjudication case.  The Department of Ecology picked a big fight here when they sent summonses to 30,000 people.  The case is going to take a while, a long while, and the court should be concerned about the viability of the outcome if there are not a sufficiently proximate number of affected parties

Folks who live in the country with single family wells should especially want to get their water claims adjudicated.  If they don't, when they go to sell someday, they may find that a title report reveals that they don't have a water right.  In the old days, everyone just assumed that if there was a well on the property, there was a water right.  Won't be the case any more when this adjudication is complete, at least formally.

"Negotiation" at this juncture is premature, because all the relevant parties don't have to come to the table.  But the adjudication sets up a process where negotiation can be meaningful.  The McCarran Act (where Congress waived the sovereignty of the US allowing state court judges to de"Watermine federal and tribal water rights) enables the setting of a judicial "negotiation table" at which contesting parties can negotiate their advocated interests.  Resolution of their differences can be proposed as judicial orders.  That's the way most adjudications get finished.  Where the parties cannot resolve things, the court must "split the baby." 

This water adjudication is about more than just whether cities have enough water to serve their growing populations, whether farmers have enough water to generate profit, or at least sustenance, from their agricultural property, or whether tribes' treaty rights are correctly respected.  It's also about environmental and species quality under conditions of climate change.  And it's about the public good.  "Water belongs to the public," afterall.  RCW 90.03.010 

RCW 90.54.020 says:  "(1) Uses of water for domestic, stock watering, industrial, commercial, agricultural, irrigation, hydroelectric power producxtion, mining, fish and wildlife maintenance and enhancement, recreational, and thermal power production purposes, and preservation of environmental and aesthetic values, and all other uses compatible with the enjoyment of the public waters of the state, are declared to be beneficial.

(2) Allocxation of waters among potential uses and users shall be based generally on the securing of the maximum net benefits for the people of the state.  Maximum net benefits shall constitute total benefits less costs including opportunities lost.

(3) The quality of the natural environment shall be protected and, where possible, enhanced as follows:

(a) Perennial rivers and streams of the state shall be retained with base flows necessary to provide for preservation of wildlife, fish, scenic, aesthetic and other environmental values, and navigational values.  Lakes and ponds shall be retained substantially in their natural condition.  Withdrawals of water  which would conflict therewith shall be authorized only in those situations where it is clear that overriding considerations of the public interest will be served.

Myself, I intend to stick up for these legislatively declared policies.