diff --git a/src/shared_utilities/Domains.jl b/src/shared_utilities/Domains.jl
index 9412fbf7ed..5bc5ce751d 100644
--- a/src/shared_utilities/Domains.jl
+++ b/src/shared_utilities/Domains.jl
@@ -910,10 +910,39 @@ function get_additional_domain_fields(subsurface_space)
     face_space = obtain_face_space(subsurface_space)
     z_face = ClimaCore.Fields.coordinate_field(face_space).z
     z_sfc = top_face_to_surface(z_face, surface_space)
-    fields = (; z = z, Δz_top = Δz_top, Δz_bottom = Δz_bottom, z_sfc = z_sfc)
+    d = depth(subsurface_space)
+    fields = (;
+        z = z,
+        Δz_top = Δz_top,
+        Δz_bottom = Δz_bottom,
+        z_sfc = z_sfc,
+        depth = d,
+    )
     return fields
 end
 
+"""
+    depth(space::Union{ClimaCore.Spaces.CenterFiniteDifferenceSpace,
+                       ClimaCore.Spaces.CenterExtrudedFiniteDifferenceSpace}) 
+
+Returns the depth of the domain as a scalar. Note that these functions
+will need to be modified upon the introduction of 
+- topography at surface
+- depth to bedrock (topography at bottom)
+
+Since the depth will be a field in this case, it should be allocated and
+stored in domain.fields, which is why we store it there now even though it is not a field.
+"""
+depth(space::ClimaCore.Spaces.CenterExtrudedFiniteDifferenceSpace) =
+    (
+        space.grid.vertical_grid.topology.mesh.domain.coord_max -
+        space.grid.vertical_grid.topology.mesh.domain.coord_min
+    ).z
+depth(space::ClimaCore.Spaces.CenterFiniteDifferenceSpace) =
+    (
+        space.grid.topology.mesh.domain.coord_max -
+        space.grid.topology.mesh.domain.coord_min
+    ).z
 
 export AbstractDomain
 export Column, Plane, HybridBox, Point, SphericalShell, SphericalSurface
diff --git a/src/standalone/Soil/Runoff/Runoff.jl b/src/standalone/Soil/Runoff/Runoff.jl
index d88b5ba6a4..da52a024b8 100644
--- a/src/standalone/Soil/Runoff/Runoff.jl
+++ b/src/standalone/Soil/Runoff/Runoff.jl
@@ -228,7 +228,7 @@ function update_runoff!(
     @. p.soil.R_ss = topmodel_ss_flux(
         runoff.subsurface_source.R_sb,
         runoff.f_over,
-        model.domain.depth - p.soil.h∇,
+        model.domain.fields.depth - p.soil.h∇,
     )
     ic = soil_infiltration_capacity(model, Y, p) # should be non-allocating
 
@@ -237,7 +237,7 @@ function update_runoff!(
         p.soil.h∇,
         runoff.f_max,
         runoff.f_over,
-        model.domain.depth - p.soil.h∇,
+        model.domain.fields.depth - p.soil.h∇,
         ic,
         precip,
     )
diff --git a/test/shared_utilities/domains.jl b/test/shared_utilities/domains.jl
index d4c343ffb4..baa69b0bb3 100644
--- a/test/shared_utilities/domains.jl
+++ b/test/shared_utilities/domains.jl
@@ -37,6 +37,7 @@ FT = Float32
         nelements = n_elements_sphere,
         npolynomial = npoly_sphere,
     )
+    @test shell.fields.depth == depth
     @test shell.fields.z ==
           ClimaCore.Fields.coordinate_field(shell.space.subsurface).z
     face_space = obtain_face_space(shell.space.subsurface)
@@ -102,6 +103,7 @@ FT = Float32
         nelements = nelements,
         npolynomial = 0,
     )
+    @test box.fields.depth == zlim[2] - zlim[1]
     @test box.fields.z ==
           ClimaCore.Fields.coordinate_field(box.space.subsurface).z
     face_space = obtain_face_space(box.space.subsurface)
@@ -210,6 +212,7 @@ FT = Float32
         nelements = nelements,
         npolynomial = 0,
     )
+    @test longlat_box.fields.depth == zlim[2] - zlim[1]
     @test longlat_box.fields.z ==
           ClimaCore.Fields.coordinate_field(longlat_box.space.subsurface).z
     face_space = obtain_face_space(longlat_box.space.subsurface)
@@ -252,6 +255,7 @@ FT = Float32
     z_column = Column(; zlim = zlim, nelements = nelements[3])
     @test z_column.fields.z ==
           ClimaCore.Fields.coordinate_field(z_column.space.subsurface).z
+    @test z_column.fields.depth == zlim[2] - zlim[1]
     face_space = obtain_face_space(z_column.space.subsurface)
     z_face = ClimaCore.Fields.coordinate_field(face_space).z
     @test z_column.fields.z_sfc ==