From 54766139f6b9c543faf348dc28c214c1807354ee Mon Sep 17 00:00:00 2001
From: mkarim-rtx <149624049+mkarim-rtx@users.noreply.github.com>
Date: Wed, 11 Mar 2026 08:29:50 -0700
Subject: [PATCH 1/5] chnaged the
 atmosphere_water__liquid_equivalent_precipitation_rate_out value to match
 with atmosphere_water__liquid_equivalent_precipitation_rate (#6)

---
 src/bmi_topmodel.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/bmi_topmodel.c b/src/bmi_topmodel.c
index 54f3256..6e1aa22 100755
--- a/src/bmi_topmodel.c
+++ b/src/bmi_topmodel.c
@@ -810,8 +810,8 @@ static int Get_value_ptr(Bmi *self, const char *name, void **dest) {
     if (strcmp(name, "atmosphere_water__liquid_equivalent_precipitation_rate_out") == 0) {
         topmodel_model *topmodel;
         topmodel = (topmodel_model *)self->data;
-        *dest    = (void *)&topmodel->p;
-        //*dest = (void*)&topmodel->rain[1]; Note: these are the same ==, either would work
+        //*dest    = (void *)&topmodel->p;//Note: these are the same ==, either would work
+        *dest = (void*)&topmodel->rain[1]; 
         return BMI_SUCCESS;
         // ep
     }

From 6259302492941fbae086a685a80c5b4632cf822d Mon Sep 17 00:00:00 2001
From: Ian Todd <48330440+idtodd@users.noreply.github.com>
Date: Fri, 13 Mar 2026 09:44:06 -0400
Subject: [PATCH 2/5] Reset Time Signal (NGWPC-9621) (#5)

---
 include/bmi_serialization.h |  2 +-
 include/topmodel.h          | 20 +++++-----
 include/vecbuf.hpp          | 12 +++++-
 src/bmi_serialization.cpp   | 51 +++++++++++++++++++++----
 src/bmi_topmodel.c          | 33 ++++++++++------
 src/topmodel.c              | 76 ++++++++++++++++++-------------------
 6 files changed, 124 insertions(+), 70 deletions(-)

diff --git a/include/bmi_serialization.h b/include/bmi_serialization.h
index 2ceb763..b1e776c 100644
--- a/include/bmi_serialization.h
+++ b/include/bmi_serialization.h
@@ -8,7 +8,7 @@ extern "C" {
 #include "bmi.h"
 
 const int serialize_topmodel(Bmi* bmi);
-const int deserialize_topmodel(Bmi* bmi, const char* buffer);
+const int deserialize_topmodel(Bmi* bmi, char* buffer);
 
 #ifdef __cplusplus
 }
diff --git a/include/topmodel.h b/include/topmodel.h
index b6333da..6fe0306 100755
--- a/include/topmodel.h
+++ b/include/topmodel.h
@@ -26,28 +26,28 @@
 
 /*** Function/subroutine prototypes ***/
 extern void convert_dist_to_histords(const double * const dist_from_outlet, const int num_channels,
-					const double * const chv, const double * const rv, const double dt, double* const tch);
+					const double chv, const double rv, const double dt, double* const tch);
 
 extern void calc_time_delay_histogram(int num_channels, double area,
-		double* tch, double *cum_dist_area_with_dist,
+		const double *tch, const double *cum_dist_area_with_dist,
 		int *num_time_delay_histo_ords, int *num_delay,	double **time_delay_histogram);
 
 extern void init_water_balance(
-				int num_topodex_values, double dt, double *sr0, 
-				double *szm, double *Q0, double *t0, double tl,
+				int num_topodex_values, double dt, double sr0, 
+				double szm, double Q0, double t0, double tl,
 				double **stor_unsat_zone, double *szq,
 				double **deficit_local, double **deficit_root_zone, 
 				double *sbar, double *bal);
 
-extern void init_discharge_array(int stand_alone, int *num_delay, double *Q0, double area, 
-			int *num_time_delay_histo_ords, double **time_delay_histogram,
+extern void init_discharge_array(int stand_alone, int num_delay, double Q0, double area, 
+			int num_time_delay_histo_ords, double **time_delay_histogram,
                         double **Q);
 
 extern int init(FILE *in_param_fptr, FILE *output_fptr, char *subcat, int stand_alone,
 	      int num_channels, int num_topodex_values, int yes_print_output,
 	      double area, double **time_delay_histogram,
 	      double *cum_dist_area_with_dist, double dt, 
-        double tl, double *dist_from_outlet, 
+        double tl, const double *dist_from_outlet, 
 	      int *num_time_delay_histo_ords,int *num_delay,
 	      double *szm, double *t0, double *chv, double *rv, double *td, double *srmax, 
         double *Q0,double *sr0, int *infex, double *xk0, double *hf, double *dth,
@@ -61,11 +61,11 @@ extern int inputs(FILE *input_fptr, int *nstep, double *dt, double **rain,
 extern void topmod(FILE *output_fptr, int nstep, int num_topodex_values,
                 int yes_print_output,int infex, double dt, double szm,
 	        double *stor_unsat_zone, double *deficit_root_zone,
-                double *deficit_local, double *pe, double *rain,double xk0,double hf, 
-                double *dist_area_lnaotb, double tl, double *lnaotb, double td,
+                double *deficit_local, const double *pe, const double *rain,double xk0,double hf, 
+                const double *dist_area_lnaotb, double tl, const double *lnaotb, double td,
                 double srmax, double *contrib_area, double szq, double *Qout, 
                 int num_time_delay_histo_ords,double *Q,
-                double *time_delay_histogram,char *subcat,double *bal,
+                const double *time_delay_histogram,
                 double *sbar,int num_delay, int current_time_step, int stand_alone,
                 double *sump, double *sumae, double *sumq, double *sumrz, double *sumuz,
                 double *quz, double *qb, double *qof, double *p, double *ep);
diff --git a/include/vecbuf.hpp b/include/vecbuf.hpp
index 6db982c..a20bc70 100644
--- a/include/vecbuf.hpp
+++ b/include/vecbuf.hpp
@@ -28,6 +28,9 @@ class vecbuf : public std::basic_streambuf<CharT> {
     // Forwarder for std::vector::clear()
     constexpr void clear() { vector_.clear(); }
 
+    // Forwarder for std::vector::resize(size)
+    constexpr void resize(size_type size) { vector_.resize(size); }
+
     // Forwarder for std::vector::reserve
     constexpr void reserve(size_type capacity) { vector_.reserve(capacity); setp_from_vector(); }
 
@@ -35,7 +38,7 @@ class vecbuf : public std::basic_streambuf<CharT> {
     constexpr void reserve_additional(size_type additional_capacity) { reserve(size() + additional_capacity); }
 
     // Forwarder for std::vector::data
-    constexpr const value_type* data() const { return vector_.data(); }
+    constexpr value_type* data() { return vector_.data(); }
 
     // Forwarder for std::vector::size
     constexpr size_type size() const { return vector_.size(); }
@@ -112,4 +115,11 @@ class vecbuf : public std::basic_streambuf<CharT> {
 
 };
 
+class membuf : public std::streambuf {
+public:
+    membuf(char *begin, size_t size) {
+        this->setg(begin, begin, begin + size);
+    }
+};
+
 #endif
diff --git a/src/bmi_serialization.cpp b/src/bmi_serialization.cpp
index 03a3448..4daa17d 100644
--- a/src/bmi_serialization.cpp
+++ b/src/bmi_serialization.cpp
@@ -32,6 +32,12 @@ class TopmodelSerializer {
 template<class Archive>
 void TopmodelSerializer::serialize(Archive& ar, const unsigned int version) {
     topmodel_model* model = this->model;
+    if (model->stand_alone == TRUE) {
+        // the number of timesteps makes hindcasting nigh imposible when stand alone
+        auto error = "Topmodel serialization is not currently implemented when running stand alone.";
+        Log(SEVERE, error);
+        throw std::runtime_error(error);
+    }
     ar & model->current_time_step;
 
     // data summed between runs
@@ -62,12 +68,37 @@ void TopmodelSerializer::serialize(Archive& ar, const unsigned int version) {
     ar & boost::serialization::make_array(
         model->deficit_local, num_topodex_values
     );
+
+    // nsteps will always be 1 for non-stand-alone models
     ar & boost::serialization::make_array(
-        model->contrib_area, num_topodex_values
+        model->contrib_area, model->nstep + 1
     );
+
+    // copy the current sizes to detect changes, then archive the model value
+    int num_time_delay_histo_ords = model->num_time_delay_histo_ords;
+    ar & model->num_time_delay_histo_ords;
+    int num_delay = model->num_delay;
+    ar & model->num_delay;
+    size_t num_Q = model->num_delay + model->num_time_delay_histo_ords + 1;
+    if (Archive::is_loading::value) {
+        // if loading and array size has changed, reallocate
+        if (num_time_delay_histo_ords != model->num_time_delay_histo_ords) {
+            if (model->time_delay_histogram != NULL)
+                free(model->time_delay_histogram);
+            model->time_delay_histogram = (double *)malloc(
+                (model->num_time_delay_histo_ords + 1) * sizeof(double)
+            );
+        }
+        if (num_delay != model->num_delay || num_time_delay_histo_ords != model->num_time_delay_histo_ords) {
+            if (model->Q != NULL)
+                free(model->Q);
+            model->Q = (double *)malloc(num_Q * sizeof(double));
+        }
+    }
     ar & boost::serialization::make_array(
-        model->Q, model->num_time_delay_histo_ords + 1
+        model->time_delay_histogram, model->num_time_delay_histo_ords + 1
     );
+    ar & boost::serialization::make_array(model->Q, num_Q);
 }
 
 
@@ -99,15 +130,17 @@ const int serialize_topmodel(Bmi* bmi) {
         free(model->serialized);
     }
     // set size and allocate memory
-    model->serialized_length = stream.size();
-    model->serialized = (char*)malloc(sizeof(char) * model->serialized_length);
+    uint64_t serialized_size = stream.size();
+    model->serialized_length = serialized_size + sizeof(uint64_t);
+    model->serialized = (char*)malloc(model->serialized_length);
     // make sure memory could be allocated
     if (model->serialized == NULL) {
         model->serialized_length = 0;
         return BMI_FAILURE;
     }
     // copy stream data to new allocation
-    memcpy(model->serialized, stream.data(), model->serialized_length);
+    memcpy(model->serialized, &serialized_size, sizeof(uint64_t));
+    memcpy(model->serialized + sizeof(uint64_t), stream.data(), serialized_size);
     return BMI_SUCCESS;
 }
 
@@ -118,9 +151,13 @@ const int serialize_topmodel(Bmi* bmi) {
   * @param buffer Start of data that wil be read as previously serialized state
   * @return int signifiying whether the serialization process completed successfully.
   */
-const int deserialize_topmodel(Bmi* bmi, const char* buffer) {
+const int deserialize_topmodel(Bmi* bmi, char* buffer) {
     TopmodelSerializer serializer(bmi);
-    std::istringstream stream(buffer);
+    // copy size of data out of header
+    uint64_t size;
+    memcpy(&size, buffer, sizeof(uint64_t));
+    // create stream from data after header
+    membuf stream(buffer + sizeof(uint64_t), size);
     boost::archive::binary_iarchive archive(stream);
     try {
         archive >> serializer;
diff --git a/src/bmi_topmodel.c b/src/bmi_topmodel.c
index 6e1aa22..8c1e2da 100755
--- a/src/bmi_topmodel.c
+++ b/src/bmi_topmodel.c
@@ -481,8 +481,6 @@ static int Update(Bmi *self) {
         topmodel->num_time_delay_histo_ords,
         topmodel->Q,
         topmodel->time_delay_histogram,
-        topmodel->subcat,
-        &topmodel->bal,
         &topmodel->sbar,
         topmodel->num_delay,
         topmodel->current_time_step,
@@ -652,6 +650,9 @@ static int Get_var_type(Bmi *self, const char *name, char *type) {
     } else if (strcmp(name, "serialization_free") == 0) {
         strncpy(type, "int", BMI_MAX_TYPE_NAME);
         return BMI_SUCCESS;
+    } else if (strcmp(name, "reset_time") == 0) {
+        strncpy(type, "double", BMI_MAX_TYPE_NAME);
+        return BMI_SUCCESS;
     }
     // If we get here, it means the variable name wasn't recognized
     type[0] = '\0';
@@ -776,7 +777,10 @@ static int Get_var_nbytes(Bmi *self, const char *name, int *nbytes) {
     }
     // special cases for save state
     if (item_count < 1) {
-        if (strcmp(name, "serialization_create") == 0 || strcmp(name, "serialization_size") == 0 || strcmp(name, "serialization_free") == 0) {
+        if (strcmp(name, "serialization_create") == 0
+            || strcmp(name, "serialization_size") == 0
+            || strcmp(name, "serialization_free") == 0
+            || strcmp(name, "reset_time") == 0) {
             item_count = 1;
         } else if (strcmp(name, "serialization_state") == 0) {
             topmodel_model* model = (topmodel_model*)self->data;
@@ -1063,6 +1067,11 @@ static int Set_value(Bmi *self, const char *name, void *array) {
         } else {
             return BMI_FAILURE;
         }
+    } else if (strcmp(name, "reset_time") == 0) {
+        topmodel_model* model = (topmodel_model *)self->data;
+        // current_time_step is mainly used for indexing into config data, so should be safe to reset and nothing else
+        model->current_time_step = 0;
+        return BMI_SUCCESS;
     }
 
     if (self->get_value_ptr(self, name, &dest) == BMI_FAILURE)
@@ -1168,8 +1177,8 @@ static int Set_value(Bmi *self, const char *name, void *array) {
         convert_dist_to_histords(
             topmodel->dist_from_outlet,
             topmodel->num_channels,
-            &topmodel->chv,
-            &topmodel->rv,
+            topmodel->chv,
+            topmodel->rv,
             topmodel->dt,
             tch
         );
@@ -1188,10 +1197,10 @@ static int Set_value(Bmi *self, const char *name, void *array) {
         // Reinitialise discharge array
         init_discharge_array(
             topmodel->stand_alone,
-            &topmodel->num_delay,
-            &topmodel->Q0,
+            topmodel->num_delay,
+            topmodel->Q0,
             topmodel->area,
-            &topmodel->num_time_delay_histo_ords,
+            topmodel->num_time_delay_histo_ords,
             &topmodel->time_delay_histogram,
             &topmodel->Q
         );
@@ -1211,10 +1220,10 @@ static int Set_value(Bmi *self, const char *name, void *array) {
         init_water_balance(
             topmodel->num_topodex_values,
             topmodel->dt,
-            &topmodel->sr0,
-            &topmodel->szm,
-            &topmodel->Q0,
-            &topmodel->t0,
+            topmodel->sr0,
+            topmodel->szm,
+            topmodel->Q0,
+            topmodel->t0,
             topmodel->tl,
             &topmodel->stor_unsat_zone,
             &topmodel->szq,
diff --git a/src/topmodel.c b/src/topmodel.c
index 335931b..4eeea89 100755
--- a/src/topmodel.c
+++ b/src/topmodel.c
@@ -119,13 +119,13 @@ extern void topmod(
     double *stor_unsat_zone,
     double *deficit_root_zone,
     double *deficit_local,
-    double *pe,
-    double *rain,
+    const double *pe,
+    const double *rain,
     double xk0,
     double hf,
-    double *dist_area_lnaotb,
+    const double *dist_area_lnaotb,
     double tl,
-    double *lnaotb,
+    const double *lnaotb,
     double td,
     double srmax,
     double *contrib_area,
@@ -133,9 +133,7 @@ extern void topmod(
     double *Qout,
     int num_time_delay_histo_ords,
     double *Q,
-    double *time_delay_histogram,
-    char *subcat,
-    double *bal,
+    const double *time_delay_histogram,
     double *sbar,
     int num_delay,
     int current_time_step,
@@ -689,8 +687,8 @@ extern int tread(
 extern void convert_dist_to_histords(
     const double *const dist_from_outlet,
     const int num_channels,
-    const double *const chv,
-    const double *const rv,
+    const double chv,
+    const double rv,
     const double dt,
     double *const tch
 ) {
@@ -705,8 +703,8 @@ extern void convert_dist_to_histords(
     double chvdt, rvdt;
     int j;
 
-    chvdt = *chv * dt; // distance water travels in one timestep within channel
-    rvdt  = *rv * dt; // distance water travels as overland flow in one timestep
+    chvdt = chv * dt; // distance water travels in one timestep within channel
+    rvdt  = rv * dt; // distance water travels as overland flow in one timestep
 
     tch[1] = dist_from_outlet[1] / chvdt;
     for (j = 2; j <= num_channels; j++) {
@@ -741,8 +739,8 @@ extern void convert_dist_to_histords(
 extern void calc_time_delay_histogram(
     int num_channels,
     double area,
-    double *tch,
-    double *cum_dist_area_with_dist,
+    const double *tch,
+    const double *cum_dist_area_with_dist,
     int *num_time_delay_histo_ords,
     int *num_delay,
     double **time_delay_histogram
@@ -861,10 +859,10 @@ extern void calc_time_delay_histogram(
  */
 extern void init_discharge_array(
     int stand_alone,
-    int *num_delay,
-    double *Q0,
+    int num_delay,
+    double Q0,
     double area,
-    int *num_time_delay_histo_ords,
+    int num_time_delay_histo_ords,
     double **time_delay_histogram,
     double **Q
 ) {
@@ -876,7 +874,7 @@ extern void init_discharge_array(
             *Q = NULL;
         }
         //*Q = calloc(*num_delay + *num_time_delay_histo_ords + 1, sizeof(double));
-        d_alloc(Q, *num_delay + *num_time_delay_histo_ords);
+        d_alloc(Q, num_delay + num_time_delay_histo_ords);
     }
 
     // declare local variables
@@ -885,14 +883,14 @@ extern void init_discharge_array(
 
     sum = 0.0;
 
-    for (i = 1; i <= (*num_delay); i++) {
-        (*Q)[i] += (*Q0) * area;
+    for (i = 1; i <= (num_delay); i++) {
+        (*Q)[i] += Q0 * area;
     }
 
-    for (i = 1; i <= (*num_time_delay_histo_ords); i++) {
+    for (i = 1; i <= num_time_delay_histo_ords; i++) {
         sum += (*time_delay_histogram)[i];
-        in = (*num_delay) + i;
-        (*Q)[in] += (*Q0) * (area - sum);
+        in = num_delay + i;
+        (*Q)[in] += Q0 * (area - sum);
     };
 
     return;
@@ -931,10 +929,10 @@ extern void init_discharge_array(
 extern void init_water_balance(
     int num_topodex_values,
     double dt,
-    double *sr0,
-    double *szm,
-    double *Q0,
-    double *t0,
+    double sr0,
+    double szm,
+    double Q0,
+    double t0,
     double tl,
     double **stor_unsat_zone,
     double *szq,
@@ -960,20 +958,20 @@ extern void init_water_balance(
     // document the assumption and the requirement for caller to size these arrays to
     // num_topodex_values
 
-    t0dt = (*t0) + log(dt); /* was ALOG - specific log function in fortran*/
+    t0dt = t0 + log(dt); /* was ALOG - specific log function in fortran*/
 
     /*  Calculate SZQ parameter */
     (*szq) = exp(t0dt - tl);
 
     for (ia = 1; ia <= num_topodex_values; ia++) {
         (*stor_unsat_zone)[ia]   = 0.0;
-        (*deficit_root_zone)[ia] = (*sr0);
+        (*deficit_root_zone)[ia] = sr0;
     }
 
-    (*sbar) = -(*szm) * log((*Q0) / (*szq));
+    (*sbar) = (-szm) * log(Q0 / (*szq));
 
     //  Initialise water balance.  BAL is positive for storage
-    (*bal) = -(*sbar) - (*sr0);
+    (*bal) = -(*sbar) - sr0;
 
     return;
 }
@@ -1072,7 +1070,7 @@ extern int init(
     double *cum_dist_area_with_dist,
     double dt,
     double tl,
-    double *dist_from_outlet,
+    const double *dist_from_outlet,
     int *num_time_delay_histo_ords,
     int *num_delay,
     double *szm,
@@ -1149,7 +1147,7 @@ extern int init(
 
     // NJF num_channels is the value provided (SHOULD COME FROM TREAD)
     // Convert distance/area form to time delay histogram ordinates
-    convert_dist_to_histords(dist_from_outlet, num_channels, chv, rv, dt, tch);
+    convert_dist_to_histords(dist_from_outlet, num_channels, *chv, *rv, dt, tch);
 
     // calculate the time_delay_histogram
     calc_time_delay_histogram(
@@ -1165,10 +1163,10 @@ extern int init(
     // Reinitialise discharge array
     init_discharge_array(
         stand_alone,
-        num_delay,
-        Q0,
+        *num_delay,
+        *Q0,
         area,
-        num_time_delay_histo_ords,
+        *num_time_delay_histo_ords,
         time_delay_histogram,
         Q
     );
@@ -1177,10 +1175,10 @@ extern int init(
     init_water_balance(
         num_topodex_values,
         dt,
-        sr0,
-        szm,
-        Q0,
-        t0,
+        *sr0,
+        *szm,
+        *Q0,
+        *t0,
         tl,
         stor_unsat_zone,
         szq,

From 1f08e9822ba3eead7c70257949337f9fa3bda2d3 Mon Sep 17 00:00:00 2001
From: "Carolyn.Maynard" <carolyn.maynard@rtx.com>
Date: Tue, 10 Mar 2026 10:24:10 -0700
Subject: [PATCH 3/5] Updates to use the nwm-ewts libraries

---
 include/bmi_topmodel.h |   1 -
 include/logger.h       |  28 +---
 src/bmi_topmodel.c     |   7 +
 src/logger.c           | 372 -----------------------------------------
 4 files changed, 14 insertions(+), 394 deletions(-)
 delete mode 100644 src/logger.c

diff --git a/include/bmi_topmodel.h b/include/bmi_topmodel.h
index 6bed3f5..264df07 100644
--- a/include/bmi_topmodel.h
+++ b/include/bmi_topmodel.h
@@ -16,7 +16,6 @@ int init_config(const char* config_file, topmodel_model* model);
 
 int read_init_config(const char* config_file, topmodel_model* model);
 
-
 #if defined(__cplusplus)
 }
 #endif
diff --git a/include/logger.h b/include/logger.h
index 5d3c9a6..646a7e0 100644
--- a/include/logger.h
+++ b/include/logger.h
@@ -1,21 +1,7 @@
-#ifndef LOGGER_H
-#define LOGGER_H
-
-#include <stdarg.h> // for variable args: va_list
-#include <stdbool.h>
-
-typedef enum {      
-    NONE = 0,
-    DEBUG = 1,
-    INFO = 2,
-    WARNING = 3,
-    SEVERE = 4,
-    FATAL = 5,
-} LogLevel;
-
-// Public Methods
-LogLevel GetLogLevel(void);
-bool IsLoggingEnabled(void);
-void Log(LogLevel messageLevel, const char* message, ...);
-
-#endif // LOGGER_H
+#ifndef TOPMODEL_LOGGER_H
+#define TOPMODEL_LOGGER_H
+#include "ewts/module_constants.h"
+#define EWTS_ID EWTS_ID_TOPMODEL
+#include "ewts/logger.h"
+#include "ewts/log_levels.h"
+#endif /* TOPMODEL_LOGGER_H */
diff --git a/src/bmi_topmodel.c b/src/bmi_topmodel.c
index 8c1e2da..ef39709 100755
--- a/src/bmi_topmodel.c
+++ b/src/bmi_topmodel.c
@@ -412,6 +412,13 @@ static int Initialize(Bmi *self, const char *cfg_file) {
     topmodel_model *topmodel;
     topmodel = (topmodel_model *)self->data;
 
+    // Initialize the Error, Warning and Trapping System
+#ifdef EWTS_HAVE_NGEN_BRIDGE    
+    EwtsInit(EWTS_ID_TOPMODEL, true);
+#else
+    EwtsInit(EWTS_ID_TOPMODEL, false);
+#endif    
+    
     // Read and setup data from file
     int ret = init_config(cfg_file, topmodel);
     if (ret != BMI_SUCCESS)
diff --git a/src/logger.c b/src/logger.c
deleted file mode 100644
index 1cf25d4..0000000
--- a/src/logger.c
+++ /dev/null
@@ -1,372 +0,0 @@
-#include "logger.h"
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <sys/wait.h>
-#include <sys/stat.h>
-#include <sys/time.h>
-#include <errno.h>
-#include <time.h>
-#include <unistd.h>
-#include <ctype.h>
-#include <stdbool.h>
-
-// Define Environment Variable Names
-#define MODULE_NAME           "TopModel"
-#define EV_MODULE_LOGLEVEL    "TOPMODEL_LOGLEVEL"     // This modules log level
-#define EV_MODULE_LOGFILEPATH "TOPMODEL_LOGFILEPATH"  // This modules log full log filename
-#define EV_NGEN_LOGFILEPATH   "NGEN_LOG_FILE_PATH"    // ngen log file 
-
-#define EV_EWTS_LOGGING       "NGEN_EWTS_LOGGING"     // Enable/disable of Error Warning and Trapping System  
-
-#define DS                    "/"                     // Directory separator
-#define LOG_DIR_NGENCERF      "/ngencerf/data"        // ngenCERF log directory
-#define LOG_DIR_DEFAULT       "run-logs"              // Default subdir if ngen log file env not found
-#define LOG_FILE_EXT          "log"
-#define LOG_MODULE_NAME_LEN   8                       // Width of module name for log entries
-
-bool     loggingEnabled = true;
-bool     openedAppendMode = true;
-bool     loggerInitialized = false;
-FILE*    logFile = NULL;
-char     logFilePath[1024] = "";
-LogLevel logLevel = INFO;
-char     moduleName[LOG_MODULE_NAME_LEN+1] = "";
-
-void TrimString(const char *input, char *output, size_t outputSize) {
-    if (!input || !output || outputSize == 0) {
-        if (output && outputSize > 0) output[0] = '\0';
-        return;
-    }
-
-    // Skip leading whitespace
-    while (isspace((unsigned char)*input)) {
-        input++;
-    }
-
-    size_t len = strlen(input);
-    if (len == 0) {
-        output[0] = '\0';
-        return;
-    }
-
-    // Find the end of the string and move backward past trailing whitespace
-    const char *end = input + len - 1;
-    while (end > input && isspace((unsigned char)*end)) {
-        end--;
-    }
-
-    size_t trimmedLen = end - input + 1;
-    if (trimmedLen >= outputSize) {
-        trimmedLen = outputSize - 1;
-    }
-
-    strncpy(output, input, trimmedLen);
-    output[trimmedLen] = '\0';
-}
-
-void SetLogModuleName(void) {
-
-    // Copy MODULE_NAME to a string variable 
-    char src[20];
-    strncpy(src, MODULE_NAME, sizeof(src));
-    src[sizeof(src) - 1] = '\0'; // ensure null termination
-
-    // Convert to uppercase and copy, up to width or null terminator
-    size_t i = 0;
-    for (; i < LOG_MODULE_NAME_LEN && src[i] != '\0'; i++) {
-        moduleName[i] = toupper((unsigned char)src[i]);
-    }
-
-    // Pad with spaces if needed
-    for (; i < LOG_MODULE_NAME_LEN; i++) {
-        moduleName[i] = ' ';
-    }
-    moduleName[LOG_MODULE_NAME_LEN] = '\0'; // null-terminate
-}
-
-void CreateTimestamp(char *buffer, size_t size, bool appendMS, bool iso) {
-    struct timeval tv;
-    gettimeofday(&tv, NULL);
-
-    struct tm utc_tm;
-    gmtime_r(&tv.tv_sec, &utc_tm);
-
-    char base[32];
-    if (iso) {
-        strftime(base, sizeof(base), "%Y-%m-%dT%H:%M:%S", &utc_tm);
-    } else {
-        strftime(base, sizeof(base), "%Y%m%dT%H%M%S", &utc_tm);
-    }
-
-    if (appendMS) {
-        snprintf(buffer, size, "%s.%03ld", base, tv.tv_usec / 1000);
-    } else {
-        snprintf(buffer, size, "%s", base);
-    }
-}
-
-bool DirectoryExists(const char *path) {
-    struct stat info;
-    return (stat(path, &info) == 0 && (info.st_mode & S_IFDIR));
-}
-
-bool CreateDirectory(const char *path) {
-    if (!DirectoryExists(path)) {
-        char cmd[512];
-        snprintf(cmd, sizeof(cmd), "mkdir -p \"%s\"", path);
-        int status = system(cmd);
-        if (status == -1 || (WIFEXITED(status) && WEXITSTATUS(status) != 0)) {
-            fprintf(stderr, "Failed to create directory: %s\n", path);
-            return false;
-        }
-    }
-    return true;
-}
-
-bool LogFileReady(bool appendMode) {
-    if (logFile && !ferror(logFile)) {
-        fseek(logFile, 0, SEEK_END);
-        return true;
-    } else if (strlen(logFilePath) > 0) {
-        logFile = fopen(logFilePath, appendMode ? "a" : "w");
-        if (logFile != NULL) {
-            openedAppendMode = appendMode;
-            return true;
-        }
-        return false;
-    }
-    return false;
-}
-
-/**
- * Set the log file path name using the following pattern
- *  - Use the module log file if available (unset when first run by ngen), otherwise 
- *  - Use ngen log file if available, otherwise
- *  - Use /ngencerf/data/run-logs/<username>/<module>_<YYMMDDTHHMMSS> if available, othrewise
- *  - Use ~/run-logs/<YYYYMMDD>/<module>_<YYMMDDTHHMMSS>
- *  - Onced opened, save the full log path to the modules log environment variable so
- *    it is only opened once for each ngen run (vs for each catchment)
- */
-void SetupLogFile(void) {
-    logFilePath[0] = '\0';
-    bool appendEntries = true;
-    bool moduleLogEnvExists = false;
-
-    const char *envVar = getenv(EV_MODULE_LOGFILEPATH);
-    if (envVar && envVar[0] != '\0') {
-        strncpy(logFilePath, envVar, sizeof(logFilePath) - 1);
-        moduleLogEnvExists = true;
-    } else {
-        envVar = getenv(EV_NGEN_LOGFILEPATH);
-        if (envVar && envVar[0] != '\0') {
-            strncpy(logFilePath, envVar, sizeof(logFilePath) - 1);
-        } else {
-            appendEntries = false;
-            char logFileDir[512];
-
-            if (DirectoryExists(LOG_DIR_NGENCERF)) {
-                snprintf(logFileDir, sizeof(logFileDir), "%s%s%s", LOG_DIR_NGENCERF, DS, LOG_DIR_DEFAULT);
-            } else {
-                const char *home = getenv("HOME"); // Get users home directly pathname
-                if (home) {
-                    snprintf(logFileDir, sizeof(logFileDir), "%s%s%s", home, DS, LOG_DIR_DEFAULT);
-                }
-                else {
-                    snprintf(logFileDir, sizeof(logFileDir), "~%s%s", DS, LOG_DIR_DEFAULT);
-                }
-            }
-
-            if (CreateDirectory(logFileDir)) {
-                const char *envUsername = getenv("USER");
-                if (envUsername) {
-                    strncat(logFileDir, DS, sizeof(logFileDir) - strlen(logFileDir) - 1);
-                    strncat(logFileDir, envUsername, sizeof(logFileDir) - strlen(logFileDir) - 1);
-                } else {
-                    char dateStr[32];
-                    CreateTimestamp(dateStr, sizeof(dateStr), 0, 0);
-                    strncat(logFileDir, DS, sizeof(logFileDir) - strlen(logFileDir) - 1);
-                    strncat(logFileDir, dateStr, sizeof(logFileDir) - strlen(logFileDir) - 1);
-                }
-
-                if (CreateDirectory(logFileDir)) {
-                    char timestamp[32];
-                    CreateTimestamp(timestamp, sizeof(timestamp), 0, 0);
-                    snprintf(logFilePath, sizeof(logFilePath), "%s%s%s_%s.%s",
-                             logFileDir, DS, MODULE_NAME, timestamp, LOG_FILE_EXT);
-                }
-            }
-        }
-    }
-
-    if (LogFileReady(appendEntries)) {
-        if (!moduleLogEnvExists) setenv(EV_MODULE_LOGFILEPATH, logFilePath, 1);
-        printf("Module %s Log File: %s\n", MODULE_NAME, logFilePath);
-        fflush(stdout); // Force flushing of stdout
-        LogLevel saveLevel = logLevel;
-        logLevel = INFO; // Ensure this INFO message is always logged
-        Log(logLevel, "Opened log file %s in %s mode\n", logFilePath, (openedAppendMode ? "Append" : "Truncate"));
-        logLevel = saveLevel;
-    } else {
-        printf("Unable to open log file ");
-        if (strlen(logFilePath) > 0) {
-            printf("%s (Perhaps check permissions)\n", logFilePath);
-        }
-        printf("Log entries will be written to stdout\n");
-        fflush(stdout); // Force flushing of stdout
-    }
-}
-
-const char* ConvertLogLevelToString(LogLevel level) {
-    switch (level) {
-        case DEBUG:   return "DEBUG  ";
-        case INFO:    return "INFO   ";
-        case WARNING: return "WARNING";
-        case SEVERE:  return "SEVERE ";
-        case FATAL:   return "FATAL  ";
-        default:      return "NONE   ";
-    }
-}
-
-LogLevel ConvertStringToLogLevel(const char* str) {
-    char trimmedStr[20] = {0};
-    TrimString(str, trimmedStr, sizeof(trimmedStr));
-    if (strcasecmp(trimmedStr, "DEBUG") == 0) return DEBUG;
-    if (strcasecmp(trimmedStr, "INFO")  == 0) return INFO;
-    if (strcasecmp(trimmedStr, "WARNING")  == 0) return WARNING;
-    if (strcasecmp(trimmedStr, "SEVERE") == 0) return SEVERE;
-    if (strcasecmp(trimmedStr, "FATAL") == 0) return FATAL;
-    return NONE;
-}
-
-void SetLoggingFlag(void) {
-    const char* ewtsStr = getenv(EV_EWTS_LOGGING);
-    if (ewtsStr && ewtsStr[0] != '\0') {
-        char trimmedStr[20] = {0};
-        TrimString(ewtsStr, trimmedStr, sizeof(trimmedStr));
-        bool loggingEnabled = ((strcasecmp(trimmedStr, "ENABLED") == 0))? true:false;
-    }
-    printf("%s Logging %s\n", MODULE_NAME, ((loggingEnabled)?"ENABLED":"DISABLED"));
-    fflush(stdout); // Force flushing of stdout
-}
-
-void SetLogLevel(void) {
-    const char* envLogLevel = getenv(EV_MODULE_LOGLEVEL);
-    if (envLogLevel && envLogLevel[0] != '\0') {
-        logLevel = ConvertStringToLogLevel(envLogLevel);
-    }
-    char llStr[10];
-    char msg[100];
-    TrimString(ConvertLogLevelToString(logLevel), llStr, sizeof(llStr));
-    snprintf(msg, sizeof(msg), "Log level set to %s\n", llStr);
-    printf("%s %s", MODULE_NAME, msg);
-    fflush(stdout); // Force flushing of stdout
-    LogLevel saveLevel = logLevel;
-    logLevel = INFO; // Ensure this INFO message is always logged
-    Log(logLevel, msg);
-    logLevel = saveLevel;
-}
-
-void SetLogPreferences(void) {
-
-    if (!loggerInitialized) {
-        loggerInitialized = true; // Only call this once
-        
-        SetLoggingFlag(); // Based on the environment variable
-        if (loggingEnabled) {
-            SetLogModuleName(); // Set the module name used in log entries
-            SetupLogFile();
-            SetLogLevel();
-            // FOR TESTING ONLY! Uncomment next line to generate test log entries
-            // WriteLogTestMsgs();
-        }
-    }
-}
-
-void TrimToOneNewline(char *str, size_t max_len) {
-    size_t len = strlen(str);
-
-    // Strip trailing whitespace including \n, \r, spaces, tabs
-    while (len > 0 && isspace((unsigned char)str[len - 1])) {
-        str[--len] = '\0';
-    }
-
-    // Ensure room to add a newline
-    if (len + 1 < max_len) {
-        str[len] = '\n';
-        str[len + 1] = '\0';
-    }
-}
-
-LogLevel GetLogLevel(void) {
-    return logLevel;
-}
-
-bool IsLoggingEnabled(void) {
-    return loggingEnabled;
-}
-
-void Log(LogLevel messageLevel, const char* message, ...) {
-    if (!loggerInitialized) SetLogPreferences(); // Initialize logger on first call
-
-    if (loggingEnabled && (messageLevel >= logLevel)) {
-
-        va_list arglist;
-        va_start(arglist, message);
-        va_list arglist_copy;
-        va_copy(arglist_copy, arglist);
-
-        int length = vsnprintf(NULL, 0, message, arglist_copy);
-        va_end(arglist_copy);
-
-        char *buffer = malloc(length + 1);
-        if (!buffer) return; // Always good to check
-
-        vsnprintf(buffer, length + 1, message, arglist);
-        va_end(arglist);
-
-        char timestamp[32];
-        CreateTimestamp(timestamp, sizeof(timestamp), 1, 1);
-
-        char logPrefix[128];
-        snprintf(logPrefix, sizeof(logPrefix), "%s %s %s", timestamp, moduleName, ConvertLogLevelToString(messageLevel));
-
-        TrimToOneNewline(buffer, sizeof(buffer));
-        char *line = strtok(buffer, "\n");
-        if (LogFileReady(true)) {
-            while (line != NULL) {
-                fprintf(logFile, "%s %s\n", logPrefix, line);
-                line = strtok(NULL, "\n");
-            }
-            fflush(logFile);
-        } else {
-            while (line != NULL) {
-                printf("%s %s\n", logPrefix, line);
-                line = strtok(NULL, "\n");
-            }
-            fflush(stdout);
-        }
-
-        free(buffer);
-    }
-}
-
-void WriteLogTestMsgs(void) {
-
-    LogLevel savedLogLevel = logLevel;
-    
-    setenv(EV_MODULE_LOGLEVEL, "SEVERE", 1);  Log(SEVERE, "Sample Log for LogLevel::SEVERE");
-    setenv(EV_MODULE_LOGLEVEL, "FATAL", 1);   Log(FATAL, "Sample Log for LogLevel::FATAL");
-    setenv(EV_MODULE_LOGLEVEL, "WARNING", 1); Log(WARNING, "Sample Log for LogLevel::WARNING");
-    setenv(EV_MODULE_LOGLEVEL, "INFO", 1);    Log(INFO, "Sample Log for LogLevel::INFO");
-    setenv(EV_MODULE_LOGLEVEL, "DEBUG", 1);   Log(DEBUG, "Sample Log for LogLevel::DEBUG");
-    
-    const char* multiline_log = 
-        "First line of multiline log:\n"
-        "Second line of multiline log\n"
-        "Third line of multiline log\n"
-        "Fourth line of multiline log";
-    Log(DEBUG, multiline_log);
-    
-    setenv(EV_MODULE_LOGLEVEL, ConvertLogLevelToString(savedLogLevel), 1); 
-}

From 600cc720d70fde85e67eae09fe46ff62ed07cd91 Mon Sep 17 00:00:00 2001
From: mkarim-rtx <149624049+mkarim-rtx@users.noreply.github.com>
Date: Tue, 21 Apr 2026 07:24:02 -0700
Subject: [PATCH 4/5] added nwm_ponded_depth (#8)

* added nwm_ponded_depth

* fixed typo

* alignment

* updated calculation of ponded_depth

* review feedback updates
---
 include/topmodel.h        |  4 +++-
 src/bmi_serialization.cpp |  1 +
 src/bmi_topmodel.c        | 23 ++++++++++++++++++-----
 src/topmodel.c            | 26 +++++++++++++++++++++++++-
 4 files changed, 47 insertions(+), 7 deletions(-)

diff --git a/include/topmodel.h b/include/topmodel.h
index 6fe0306..e8dc18e 100755
--- a/include/topmodel.h
+++ b/include/topmodel.h
@@ -68,7 +68,7 @@ extern void topmod(FILE *output_fptr, int nstep, int num_topodex_values,
                 const double *time_delay_histogram,
                 double *sbar,int num_delay, int current_time_step, int stand_alone,
                 double *sump, double *sumae, double *sumq, double *sumrz, double *sumuz,
-                double *quz, double *qb, double *qof, double *p, double *ep);
+                double *quz, double *qb, double *qof, double *p, double *ep, double *ponded_depth);
 
 extern int tread(FILE *subcat_fptr,FILE *output_fptr,char *subcat,
                 int *num_topodex_values,int *num_channels,double *area,
@@ -184,6 +184,7 @@ struct TopModel_Struct{
   double qof; /* flow from saturated area and infiltration excess flow*/
   double p;   /* adjusted rain*/
   double ep;  /* adjusted potential evaporation*/
+  double ponded_depth; /* queued delayed runoff depth from hydrograph ordinates */
 
   /************** Framework vars **************/ 
   int stand_alone;
@@ -208,4 +209,5 @@ typedef struct TopModel_Struct topmodel_model;
 extern void alloc_topmodel(topmodel_model *model);
 extern void free_topmodel(topmodel_model *model);
 
+
 #endif
diff --git a/src/bmi_serialization.cpp b/src/bmi_serialization.cpp
index 4daa17d..9647f60 100644
--- a/src/bmi_serialization.cpp
+++ b/src/bmi_serialization.cpp
@@ -54,6 +54,7 @@ void TopmodelSerializer::serialize(Archive& ar, const unsigned int version) {
     ar & model->qof; //
     ar & model->p; // reassigned each update; used in calc after assignment
     ar & model->ep; // reassigned each update; used in calc after assignment
+    ar & model->ponded_depth; // reassigned each update
     ar & model->sbar; // used then reassigned
 
     // array data that updates in update; counts set in config
diff --git a/src/bmi_topmodel.c b/src/bmi_topmodel.c
index ef39709..0131ef3 100755
--- a/src/bmi_topmodel.c
+++ b/src/bmi_topmodel.c
@@ -6,7 +6,7 @@
 
 /* BMI Adaption: Max i/o file name length changed from 30 to 256 */
 #define MAX_FILENAME_LENGTH   256
-#define OUTPUT_VAR_NAME_COUNT 14
+#define OUTPUT_VAR_NAME_COUNT 15
 #define INPUT_VAR_NAME_COUNT  2
 #define PARAM_VAR_NAME_COUNT  8
 
@@ -27,7 +27,8 @@ static const char *output_var_names[OUTPUT_VAR_NAME_COUNT] = {
     "land_surface_water__domain_time_integral_of_runoff_volume_flux", // sumq
     "soil_water__domain_root-zone_volume_deficit", // sumrz
     "soil_water__domain_unsaturated-zone_volume", // sumuz
-    "land_surface_water__water_balance_volume" // bal
+    "land_surface_water__water_balance_volume", // bal
+    "nwm_ponded_depth" // sum of Q[1..num_time_delay_histo_ords]
 };
 
 static const char *output_var_types[OUTPUT_VAR_NAME_COUNT] = {
@@ -44,11 +45,12 @@ static const char *output_var_types[OUTPUT_VAR_NAME_COUNT] = {
     "double",
     "double",
     "double",
+    "double",
     "double"
 };
 
 static const int output_var_item_count[OUTPUT_VAR_NAME_COUNT] =
-    {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1};
+    {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1};
 
 static const char *output_var_units[OUTPUT_VAR_NAME_COUNT] = {
     "m h-1",
@@ -64,11 +66,12 @@ static const char *output_var_units[OUTPUT_VAR_NAME_COUNT] = {
     "m",
     "m",
     "m",
+    "m",
     "m"
 };
 
 static const int output_var_grids[OUTPUT_VAR_NAME_COUNT] =
-    {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+    {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
 
 static const char *output_var_locations[OUTPUT_VAR_NAME_COUNT] = {
     "node",
@@ -84,6 +87,7 @@ static const char *output_var_locations[OUTPUT_VAR_NAME_COUNT] = {
     "node",
     "node",
     "node",
+    "node",
     "node"
 };
 
@@ -501,7 +505,8 @@ static int Update(Bmi *self) {
         &topmodel->qb,
         &topmodel->qof,
         &topmodel->p,
-        &topmodel->ep
+        &topmodel->ep,
+        &topmodel->ponded_depth
     );
 
     return BMI_SUCCESS;
@@ -911,6 +916,14 @@ static int Get_value_ptr(Bmi *self, const char *name, void **dest) {
         *dest    = (void *)&topmodel->bal;
         return BMI_SUCCESS;
     }
+
+    // ponded depth
+    if (strcmp(name, "nwm_ponded_depth") == 0) {
+        topmodel_model *topmodel;
+        topmodel = (topmodel_model *)self->data;
+        *dest    = (void *)&topmodel->ponded_depth;
+        return BMI_SUCCESS;
+    }
     // szm (parameter)
     if (strcmp(name, "szm") == 0) {
         topmodel_model *topmodel;
diff --git a/src/topmodel.c b/src/topmodel.c
index 4eeea89..a72db38 100755
--- a/src/topmodel.c
+++ b/src/topmodel.c
@@ -147,7 +147,8 @@ extern void topmod(
     double *qb,
     double *qof,
     double *p,
-    double *ep
+    double *ep,
+    double *ponded_depth
 ) {
     /*****************************************************************
 
@@ -357,6 +358,27 @@ extern void topmod(
         Q[in] += (*Qout) * time_delay_histogram[ir];
     }
 
+    /* Ponded depth: sum delayed-flow components stored in the hydrograph-
+     * ordinates portion of the routing array, excluding the pure channel-delay
+     * slots. */
+    *ponded_depth = 0.0;
+
+    if (stand_alone == TRUE) {
+        int q_start = it + num_delay;
+        int q_end   = q_start + num_time_delay_histo_ords - 1;
+
+        for (ir = q_start; ir <= q_end; ir++) {
+            *ponded_depth += Q[ir];
+        }
+    } else {
+        int q_start = num_delay + 1;
+        int q_end   = num_delay + num_time_delay_histo_ords;
+
+        for (ir = q_start; ir <= q_end; ir++) {
+            *ponded_depth += Q[ir];
+        }
+    }
+
     // Add current time flow to mass balance variable
     *sumq += Q[it];
     /* BMI Adaption: replace nstep with current_time_step */
@@ -838,6 +860,8 @@ extern void calc_time_delay_histogram(
 
     }
 
+
+
     return;
 }
 

From b0004e2895cf8833cbc07c7bd8d40254b3b23e45 Mon Sep 17 00:00:00 2001
From: Mohammed Karim <mohammed.r.karim@rtx.com>
Date: Wed, 6 May 2026 09:15:10 -0700
Subject: [PATCH 5/5] added and_surface_water__baseflow_volume_flux_m3_per_s

---
 include/topmodel.h |  1 +
 src/bmi_topmodel.c | 36 +++++++++++++++++++++++++++++++-----
 2 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/include/topmodel.h b/include/topmodel.h
index e8dc18e..46a044b 100755
--- a/include/topmodel.h
+++ b/include/topmodel.h
@@ -185,6 +185,7 @@ struct TopModel_Struct{
   double p;   /* adjusted rain*/
   double ep;  /* adjusted potential evaporation*/
   double ponded_depth; /* queued delayed runoff depth from hydrograph ordinates */
+  double qb_m3_per_s;
 
   /************** Framework vars **************/ 
   int stand_alone;
diff --git a/src/bmi_topmodel.c b/src/bmi_topmodel.c
index 0131ef3..1c71168 100755
--- a/src/bmi_topmodel.c
+++ b/src/bmi_topmodel.c
@@ -6,7 +6,7 @@
 
 /* BMI Adaption: Max i/o file name length changed from 30 to 256 */
 #define MAX_FILENAME_LENGTH   256
-#define OUTPUT_VAR_NAME_COUNT 15
+#define OUTPUT_VAR_NAME_COUNT 16
 #define INPUT_VAR_NAME_COUNT  2
 #define PARAM_VAR_NAME_COUNT  8
 
@@ -28,7 +28,8 @@ static const char *output_var_names[OUTPUT_VAR_NAME_COUNT] = {
     "soil_water__domain_root-zone_volume_deficit", // sumrz
     "soil_water__domain_unsaturated-zone_volume", // sumuz
     "land_surface_water__water_balance_volume", // bal
-    "nwm_ponded_depth" // sum of Q[1..num_time_delay_histo_ords]
+    "nwm_ponded_depth", // sum of Q[1..num_time_delay_histo_ords]
+    "land_surface_water__baseflow_volume_flux_m3_per_s"
 };
 
 static const char *output_var_types[OUTPUT_VAR_NAME_COUNT] = {
@@ -46,11 +47,12 @@ static const char *output_var_types[OUTPUT_VAR_NAME_COUNT] = {
     "double",
     "double",
     "double",
+    "double",
     "double"
 };
 
 static const int output_var_item_count[OUTPUT_VAR_NAME_COUNT] =
-    {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1};
+    {1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1};
 
 static const char *output_var_units[OUTPUT_VAR_NAME_COUNT] = {
     "m h-1",
@@ -67,11 +69,12 @@ static const char *output_var_units[OUTPUT_VAR_NAME_COUNT] = {
     "m",
     "m",
     "m",
-    "m"
+    "m",
+    "m3 s-1"
 };
 
 static const int output_var_grids[OUTPUT_VAR_NAME_COUNT] =
-    {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+    {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
 
 static const char *output_var_locations[OUTPUT_VAR_NAME_COUNT] = {
     "node",
@@ -88,6 +91,7 @@ static const char *output_var_locations[OUTPUT_VAR_NAME_COUNT] = {
     "node",
     "node",
     "node",
+    "node",
     "node"
 };
 
@@ -433,6 +437,7 @@ static int Initialize(Bmi *self, const char *cfg_file) {
     topmodel->sump              = 0.0;
     topmodel->sumae             = 0.0;
     topmodel->sumq              = 0.0;
+    topmodel->qb_m3_per_s       = 0.0;
 
     topmodel->max_contrib_area = 0.0;
 
@@ -859,6 +864,27 @@ static int Get_value_ptr(Bmi *self, const char *name, void **dest) {
         *dest    = (void *)&topmodel->qb;
         return BMI_SUCCESS;
     }
+    // qb in m3/s
+    if (strcmp(name, "land_surface_water__baseflow_volume_flux_m3_per_s") == 0) {
+        topmodel_model *topmodel;
+        topmodel = (topmodel_model *)self->data;
+
+        if (topmodel->area > 0.0) {
+            /* TOPMODEL native qb is baseflow depth rate [m h-1].
+             * NWM expects volume flow rate [m3 s-1].
+             *
+             * Conversion:
+             *   m h-1 * m2 / 3600 s h-1 = m3 s-1
+             */
+            topmodel->qb_m3_per_s = topmodel->qb * topmodel->area / 3600.0;
+        }
+        else {
+            topmodel->qb_m3_per_s = 0.0;
+        }
+
+        *dest = (void *)&topmodel->qb_m3_per_s;
+        return BMI_SUCCESS;
+    }
     // sbar
     if (strcmp(name, "soil_water__domain_volume_deficit") == 0) {
         topmodel_model *topmodel;