: There is one area you can't access without the presence of water (the
: tiny shotgun ammo alcove).
Not so! Assuming you could ever bring the sewage level down below the floor normally in-game, you can grenade hop to the alcove if you have an Assault Rifle (which you hopefully still have ammo for. Four grenades and three rows of bullets should be enough) and x2 health (Which there happens to be a recharger for!).
It takes a bit of technique (look down, run forward, hold both triggers, release momentarily to adjust aim to left, resume firing) to make it up there; similar, I'd imagine, to the pit on Never Burn Money, which I've never actually tried. It's a fair bit easier with a Network Only Spnkr (from the previous level) and again, x2 health.
Here's a quick edit to the level. Lowered the sewage, moved the spawn point, and dropped some infinitely spawning Assault Rifles, Spnkrs, x2 canisters and ammo. Happy hopping!