Any news on how safe/clean the water is to swim at Madera in terms of sewage,

Unfortunately there is no reliable testing of our beaches. Only a simulated show before major vacation periods such as Navidad, Semana Santa and Vacaciones de Verano when schools are out. The last testing was done before Christmas and La Madera was deemed well below the threshold and perfectly apt for swimming.

As someone who's seen our bay in pristine condition, I'd say the water at La Madera is certainly clean enough for swimming. There's been a small problem recently with raw sewage spilling into the canal from a plugged up tube on Avenida La Boquita, and the authorities threw some bleach into La Madera's sewage system as a temporary measure, but today the authorities are opening up the street to fix it.

Now outside the bay between Zihuatanejo and Ixtapa a dead whale washed up on the rocks, and I have no idea how that may be affecting any beaches, if at all. So if you notice a smell...