Squeeze the thawed spinach very dry until no liquid drips.
Beat the softened cream cheese in a bowl until smooth and fluffy.
Stir in sour cream and mayonnaise until the mixture is creamy.
Mix in lemon juice, garlic, dill, parsley, chives, salt, pepper, and hot sauce.
Fold in the spinach, Parmesan, and water chestnuts until evenly distributed.
Taste and adjust seasoning. Chill 30 minutes if time allows, then serve.