Re: detroit river
They're starting to get some already. The bite usually begins down around the Trenton area and slowly moves north to LSC. The old saying goes..."when the lilacs are blooming the walleye are booming" Best times IMO are mid April {for the big mama's} and all of May for the slam bam thankyou ma'am full out action.
Word of caution...this time of year, pay close attention to whats floating downstream, the thaw-out usually brings a ton of debris...some of it dangerous{dead-falls etc.just below the surface} also there is still a bunch of ice to come thru from Lake Huron...I've seen times when it will get thick enough 'so fast' that you wouldn't be able to go upstream to where you put in...makes for a fun time docking elsewhere and then finding a way back to your vehicle & trailer.
Can't wait to get out there myself again...tight lines to you!