diff --git a/code/controllers/subsystem/mapping.dm b/code/controllers/subsystem/mapping.dm
index 2ea3b29c91..3d45672c3b 100644
--- a/code/controllers/subsystem/mapping.dm
+++ b/code/controllers/subsystem/mapping.dm
@@ -41,6 +41,8 @@ SUBSYSTEM_DEF(mapping)
 	var/datum/space_level/transit
 	var/datum/space_level/empty_space
 	var/num_of_res_levels = 1
+	/// Lookup for zlevel to station z. text = num.
+	var/list/z_to_station_z_index
 
 	var/stat_map_name = "Loading..."
 
@@ -259,6 +261,12 @@ SUBSYSTEM_DEF(mapping)
 		INIT_ANNOUNCE("Loaded [name] in [(REALTIMEOFDAY - start_time)/10]s!")
 	return parsed_maps
 
+/datum/controller/subsystem/mapping/proc/setup_station_z_index()
+	z_to_station_z_index = list()
+	var/sz = 1
+	for(var/i in station_start to (station_Start + islist(config.map_file)? (length(config.map_file) - 1) : 0))
+		z_to_station_z_index["[i]"] = sz++
+
 /datum/controller/subsystem/mapping/proc/loadWorld()
 	//if any of these fail, something has gone horribly, HORRIBLY, wrong
 	var/list/FailedZs = list()
@@ -271,6 +279,8 @@ SUBSYSTEM_DEF(mapping)
 	INIT_ANNOUNCE("Loading [config.map_name]...")
 	LoadGroup(FailedZs, "Station", config.map_path, config.map_file, config.traits, ZTRAITS_STATION, FALSE, config.orientation)
 
+	setup_station_z_index()
+
 	if(SSdbcore.Connect())
 		var/datum/DBQuery/query_round_map_name = SSdbcore.NewQuery("UPDATE [format_table_name("round")] SET map_name = '[config.map_name]' WHERE id = [GLOB.round_id]")
 		query_round_map_name.Execute()
diff --git a/code/controllers/subsystem/persistence/cleanable_debris.dm b/code/controllers/subsystem/persistence/cleanable_debris.dm
index 13c80aee57..c4ef98121b 100644
--- a/code/controllers/subsystem/persistence/cleanable_debris.dm
+++ b/code/controllers/subsystem/persistence/cleanable_debris.dm
@@ -22,7 +22,11 @@
 		return
 	loaded_debris = TRUE
 	var/list/data = json_decode(file2text("[get_map_persistence_path()]/debris.json"))
-
+	var/list/z_lookup = list()
+	/// reverse it
+	for(var/z in SSmapping.z_to_station_z_index)
+		var/sz = SSmapping.z_to_station_z_index[z]
+		z_lookup[num2text(sz)] = z
 
 /datum/controller/subsystem/persistence/proc/SaveMapDebris()
 	if(fexists("[get_map_persistence_path()]/debris.json"))
@@ -32,6 +36,7 @@
 	for(var/z in SSmapping.levels_by_trait(ZTRAIT_STATION))
 		allowed_z_cache[num2text(z)] = TRUE
 	var/list/data = list()
+	var/list/z_lookup = SSmapping.z_to_station_z_index
 
 	WRITE_FILE("[get_map_persistence_path()]/debris.json", json_encode(data))