diff --git a/lib/Lacuna/DB/Result/Building/SAW.pm b/lib/Lacuna/DB/Result/Building/SAW.pm
index ec5e2549..4955e6d0 100644
--- a/lib/Lacuna/DB/Result/Building/SAW.pm
+++ b/lib/Lacuna/DB/Result/Building/SAW.pm
@@ -22,6 +22,17 @@ before has_special_resources => sub {
     }
 };
 
+around spend_efficiency => sub {
+    my ($orig, $self, $amount) = @_;
+    if ($amount * 100 < $self->body->water_stored) {
+        $self->body->spend_water($amount * 100);
+    }
+    else {
+        $orig->($self, $amount);
+    }
+    return $self;
+};
+
 use constant controller_class => 'Lacuna::RPC::Building::SAW';
 
 use constant university_prereq => 8;
diff --git a/var/www/public/changes.txt b/var/www/public/changes.txt
index 626e3fdb..4c9152ea 100644
--- a/var/www/public/changes.txt
+++ b/var/www/public/changes.txt
@@ -1,6 +1,7 @@
 3.0100
  - Add: The space station lab is now capable of producing some module plans.
  - Rule: Deployed bleeders now require a captcha to be demolished.
+ - Rule: SAWs now spend water * 100 instead of efficiency (when possible) to prevent heat damage.
  - Rule: Only ships that are performing hostile actions will trigger captchas.
  - Rule: If an account has essentia after 21 days of inactivity, it will spend 1 essentia (if possible) rather than enabling self-destruct. This allows people to keep their accounts long-term even if they want to take a break for a while.
  - API: Added get_stored_resources method to Distribution Center.