Re: water resistance
That depends how you measure resitance of water, temperature, electrodes, quantity and substance disolved in water,...
Current transfers differently through water than in solid conductors. Carriers of current in water solutions are ions which implies that pure water without ions would be very poor conductor. Interface between water solution and electrode would have typical voltage across and if electrodes are not of same material, or if they are not exposed to same concentration of solution they would have some potential across them. You could have AgCl elctrode that has lowest potential to water solution then other metals and make electrode that would be shaped to expose both electrodes equally to solution (e.g. double spiral close to each other), and measure resistance with low potential to avoid elctrolysis of water. This measurement would be dependand heavilly on temperature, so you would need to measure that as well.
I am not sure what kind of idea or problem you had in mind, but this is not straight forward as in conductors.