The concept of water storage on agriculture lands: Exploring the notion in South Florida

Peer review under responsibility of National Water Research Center.

Figures & data

Fig. 1 Map of the general study area.

Fig. 2 Simplified conceptual illustration of the mathematical model.

Table 1 Summary of ecosystem services for different DWTs and soil depths.

DWT (cm)	Soil (cm)	Farm life (years)	Total WS (ac-ft)	Years WS
61	130	107	1,222,221	76
	112	98	1,071,513	67
	71	42	169,511	11
	38	16	0	0
45	130	146	2,049,816	126
	112	135	1,859,545	115
	71	59	607,932	39
	38	16	0	0
20	130	371	6,074,020	367
	112	345	5,611,612	341
	71	175	2,713,932	171
	38	65	945,022	61

DWT = depth to the water table, WS = water storage.

Table 2 Ecosystem services differences from DWT of 61 cm.

DWT (cm)	Soil (cm)	Farm life (years)	WS (ac-ft)	Years WS
45	130	39	827,595	50
	112	37	788,032	48
	71	17	438,421	28
	38	0	0	0
20	130	264	4,851,799	291
	112	247	4,540,099	274
	71	133	2,544,421	160
	38	49	945,022	61

DWT = depth to the water table, WS = water storage.

Table 3 Ecosystem services percent increases from DWT of 61 cm.

DWT (cm)	Soil (cm)	Farm life (%)	WS (%)	Years WS (%)
45	130	36	68	66
	112	38	74	72
	71	40	259	255
	38	0	0	0
20	130	247	397	383
	112	252	424	409
	71	317	1501	1455
	38	306	945,022^a	61^a

a These scenarios did not experience a percent change because the original value was 0. The number shown is the difference from DWT of 61 cm.

Table 4 Summary of water storage costs for yield model 1.

DWT (cm)	Soil (cm)	Years WS	ΔWS (ac-ft)	ΔPVNR ($)	Total WSC ($/ac-ft)	Average	Max	Min
45	130	126	827,595	−$73,559,182	$160,979	$1278	$5522	−$41
	112	115	788,032	−$68,452,104	$155,135	$1349	$5522	−$49
	71	39	438,421	−$24,822,233	$53,804	$1380	$5522	$62
	38	0	0	−$28,091,168	$0	$0	$0	$0
20	130	367	4,851,799	−$220,276,247	$161,769	$441	$5522	−$15
	112	341	4,524,814	−$211,580,921	$156,018	$459	$5522	−$18
	71	171	2,544,421	−$105,910,914	$54,790	$320	$5522	−$57
	38	61	945,022	−$22,966,149	$1588	$26	$331	−$99

DWT = depth to water table, WS = water storage, PVNR = present value net return.

Table 5 Summary of water storage costs for yield model 2.

DWT (cm)	Soil (cm)	Years WS	ΔWS (ac-ft)	ΔPVNR ($)	Total WSC ($/ac-ft)	Average	Max	Min
45	130	126	827,595	−$89,211,935	$183,580	$1457	$6291	−$34
	112	115	788,032	−$89,567,991	$176,942	$1539	$6291	−$41
	71	39	438,421	−$38,703,251	$61,290	$1572	$6291	$71
	38	0	0	−$31,999,504	$0	$0	$0	$0
20	130	367	4,851,799	−$260,939,815	$184,874	$504	$6291	−$5
	112	341	4,540,099	−$252,952,660	$178,444	$523	$6291	−$7
	71	171	2,544,421	−$154,507,219	$64,530	$377	$6291	−$21
	38	61	945,022	−$64,074,234	$4138	$68	$377	−$36

DWT = depth to water table, WS = water storage, PVNR = present value net return.

Table 6 Summary of water storage costs for yield model 3.

DWT (cm)	Soil (cm)	Years WS	ΔWS (ac-ft)	ΔPVNR ($)	Total WSC ($/ac-ft)	Average	Max	Min
45	130	126	827,595	−$23,497,501	$41,744	$331	$1426	$0
	112	115	788,032	−$22,872,945	$40,251	$350	$1426	$0
	71	39	438,421	−$15,070,709	$13,895	$356	$1426	$16
	38	0	0	−$7,254,849	$0	$0	$0	$0
20	130	367	4,851,799	−$65,207,452	$42,275	$115	$1426	$0
	112	341	4,540,099	−$64,556,404	$40,890	$120	$1426	$0
	71	171	2,544,421	−$55,474,318	$15,908	$93	$1426	$2
	38	61	945,022	−$37,418,078	$2345	$38	$86	$16

DWT = depth to water table, WS = water storage, PVNR = present value net return.

Fig. 3 Cost of water storage over the life of a farm with a 45 cm water table depth. Model 1 (CP 96-1252) is represented in 4(a); Model 2 (CP 89-2376) is represented in 4(b); Model 3 (CP 89-2143) is represented in 4(c).

Fig. 4 Cost of water storage over the life of a farm with a 20 cm water table depth. Model 1 (CP 96-1252) is represented in 5(a); Model 2 (CP 89-2376) is represented in 5(b); Model 3 (CP 89-2143) is represented in 5(c).