As if a plan to raise water rates hadn’t already stirred up enough discontent this year, now a major monkeywrench has been thrown in the works.

The good news is that the city finally knows what’s been causing gross brown water — or sometimes a dark goo — to come out of faucets in certain areas. And the remedy for the problem-causing hydrogen sulfide and manganese in Well 9 water lines also has been identified.

But that fix — which involves well filtration and sending some special scrubbers through the affected lines — will cost about $1 million.

And that’s on top of everything else that needs to be fixed in the municipal water system. There’s also the deteriorating infrastructure in dire need of upgrading to ensure an adequate water system for the city as it continues to grow.

To pay for those sorely needed upgrades, the rates we pay for water are likely to double or go even higher over the next several years.

The City Council intended to phase in this big rate hike rather than hammering water users with the full increase all at once. That was the 4/4/4 approach that would raise the monthly rate about $4 every other year over the next six years.

However, those first two 4’s might get changed to 6’s because the need to fix the Well 9 water quality problem is urgent, and both options to pay for it are fraught with financial issues.

One option is a revenue bond, but that would saddle the city with significant interest costs the 4/4/4 plan wouldn’t cover. The other is paying cash by cleaning out most of the city’s water/sewer reserve fund, but the council is rightfully concerned about leaving no reserves to pay for unexpected repairs that could crop up before the reserve fund is replenished.

Bumping up the water rate increase from $4 a month to $6 may be inevitable, and so is another wave of resentment from the folks paying the bill.