Assuming that there are implicit verbs, it certainly should be acceptable to make them explicit. I consider the sentence to be equivalent to:
The greater the amount of total suspended solids [is], the higher the turbidity of the water [ is / must be / will be / should be / becomes / ... ].
Even with explicit verbs restored, there is no dependent clause in the sentence. There are two independent clauses. The first independent clause represents a condition, the second represents a consequence.
It is common but not necessary to express the relationship between condition and consequence with a subordinate clause. Two independent clauses can serve the same purpose, especially when supported by the relationship between the clauses' modalities.
If you do wish to represent the conditional relationship using a dependent clause, I recommend eliminating the inversions and using the word "if" to make the conditional clause subordinate:
If the amount of total suspended solids is greater, the turbidity of the water is higher.
The original sentence contains a number of unusual features. The clauses are inverted. The copular verbs are elided. The coordination is asyndetic. In spite of all of that, this type of sentence can be found in formal writing. I would expect a comma to mark the asyndetic coordination, but I otherwise find the original sentence to be unsurprising.