I went here several years ago and, while still not good, it was tolerable in the non-swimming area. \n\n1 - It looks like that haven't watered the grass since then because it was in bad shape when I first went there, and a few years later it is gone.  And by gone I mean 90% of it is dirt.  Minus 1 star\n\n2 - There aren't any trees in to provide shade, the only option is a covered picnic area with 4 tables on the non-lake side.  That will be a problem once it gets warmer.  Being in the middle of the desert, shade should be a priority because we are known for our 100+ temps for nearly half the year.  minus 1 star\n\n3 - No one that goes to Cosmo picks up poop.  Maybe it is that by being well known it attracts people that just don't belong at dog parks.  Whoever they are out in Gilbert, inconsiderate and poor etiquette are the norm, not the exception apparently.  There was a nice senior gentleman picking up the insane amounts of poo with the scooper to make it tolerable in the lake area.  There were literally hundreds of poops in the other side that no one picked up in the several hours I was there.  There were probably 20-40 poops I passed on the walk from the parking lot to the park.      -1\n\n4 - With popularity comes the morons.  You think managing a double gate and understanding its purpose would be fairly self explanatory.  WRONG!  When I arrived and left people just stood there with the doors open letting everyone's dogs get into the holding pen area and then leaving them in there.  After watching the circus for about 30 seconds each time I had to tell the people to just get out of the way.  There is no reason to hold the gate for someone so 10 dogs can pile up and come close to running away.  At the usual parks I go to I've never had this problem.  (I won't mention those in fear that the Cosmo hoard will take over my parks)      -1\n\n5 - The parking situation is a mess.  The park is huge, popularity is very high and they have very limited spots (maybe 30?) and the lot is about 100-150 yards away from the park entrance.  Obviously not a deal breaker since you are there to exercise you and your pet but certainly not convenient.  -1  \n\n6 - The lake side has the pro of gravel so there is no mud, and no grass for them to screw up by not watering it.  My dogs don't swim, but they have a habit of nibbling on poop which is why I was forced to bring them to the water side to avoid the proliferation of land mines.  +1 \n\n7 - There is a little dog area.  Therefore people with little dogs can't complain about how the big dogs are... you know... acting like regular dogs. +1\n   \nThat leaves me with 2 stars.  If your dog doesn't swim, don't waste your time, even if you live within walking distance.  Of the 6 or so dog parks I've gone to in town this is by far the worst maintained by the city but more importantly it has the patrons with the worst etiquette.  Too bad because it has huuuuuge potential.