Expenditures Associated with Conflicts Between Street Tree Root Growth and Hardscape in California, United States

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Figure 1.
Per-capita expenditures for tree-related damage tended to decrease with increasing city populations.

Table 1.

Demographic characteristics of all California cities and the sample cities.

City population class	No. cities in CA	Total population in CA cities	No. in sample	No. in sample (%)	Population in sample	Population in sample (%)
> 200,000	13	9,321,500	6	46.2	6,411,900	68.8
100,000–200,000	38	4,971,500	5	13.2	733,900	14.8
50,000–99,999	82	5,645,400	4	4.9	271,400	4.8
< 50,000	337	5,883,870	3	0.9	89,550	1.5
Total	470	25,822,270	18	3.8	7,506,750	29.1

Table 2.

Program data and annual expenditures for each city in the sample (all values in 1000s).

City	Population	Street trees	Tree budget	Repair	Mitigate/prevent	Legal	Remove/replace	Admininstration	Total
Carpenteria	14.5	3.0	55.0	49.0	8.1	1.9	18.0	1.0	78.0
Claremont	34.1	21.0	533.0	142.1	1.1	14.7	0.6	–	158.5
Lompoc	41.0	12.0	756.1	240.0	100.0	0.4	57.2	39.9	437.5
Davis	52.6	20.0	315.0	22.1	1.4	–	2.3	50.0	75.8
Lake Forest	57.6	8.0	90.0	45.5	8.5	3.0	17.6	22.5	97.1
Redwood City	71.8	21.0	629.0	344.4	69.5	21.0	24.2	47.3	506.4
Santa Barbara	89.4	22.5	650.0	326.6	47.8	28.8	25.4	24.0	452.6
Rancho Cucamonga	115.9	60.0	351.0	165.8	15.9	–	51.9	5.1	238.6
Sunnyvale	126.1	40.8	1,146.8	482.5	153.2	13.0	0.3	121.2	770.2
Orange	119.7	26.0	378.0	470.0	26.3	90.0	53.3	145.1	784.7
Modesto	178.7	76.0	2,200.0	386.8	79.7	42.0	77.3	76.0	661.8
Glendale	193.5	36.8	944.6	861.6	54.5	–	6.8	20.4	943.3
Oakland	383.9	225.0	23.9	1,000.0	50.0	–	36.9	1.5	1,088.4
Sacramento	384.8	115.0	2,453.1	930.0	50.9	7.7	29.7	43.3	1,061.6
Fresno	400.4	90.0	735.0	584.0	8.8	49.0	10.3	0.4	652.6
San Francisco	755.3	77.0	2,200.0	773.3	522.1	286.0	270.7	101.3	1,953.3
San Jose	849.4	250.0	1,700.0	1,040.0	0.0	208.0	1,109.5	130.0	2,487.5
Los Angeles	3,638.1	680.0	9,500.0	750.0	78.0	1,300.0	164.8	234.6	2,527.4
Total	7,506.8	1,784.1	24,660.5	8,613.8	1,275.7	2,065.6	1,956.7	1,063.6	14,975.4
Mean $/capita				1.64	0.17	0.38	0.26	0.22	2.68
Std error				0.38	0.08	0.08	0.14	0.05	0.42

Table 3.

Estimated annual statewide expenditures, tree-related damage.

Cost category	$ 1,000s	se ($ 1,000s)	% subtotal	$/capita^z	$/tree^y
Direct repair costs
Sidewalk	23,123	9,536	53.5	0.72	3.67
Curb and gutter	11,811	2,604	27.3	0.37	1.87
Street pavement	8,314	1,254	19.2	0.26	1.32
Subtotal	43,248	9,964	100.0	1.34	6.86
Mitigation and prevention
Root prune	2,519	2,068	56.2	0.08	0.40
Barriers	677	176	15.1	0.02	0.11
Grind	599	539	13.4	0.02	0.10
Ramp/taper	332	218	7.4	0.01	0.05
Tree well eng./other	141	125	3.2	0.00	0.02
Width reduction	212	190	4.7	0.01	0.03
Subtotal	4,481	2,168	100.0	0.14	0.71
Trip and fall payments and legal staff
Claims payments	6,914	1,586	68.2	0.21	1.10
Legal staff	3,230	1,531	31.8	0.10	0.51
Subtotal	10,143	2,205	100.0	0.31	1.61
Tree removal and replacement
Removal	5,650	3,527	82.2	0.18	0.90
Replacement	1,223	805	17.8	0.04	0.19
Subtotal	6,872	3,618	100.0	0.21	1.09
Other costs
Inspection	2,168	580	36.6	0.07	0.34
Admininstration	3,749	1,148	63.4	0.12	0.60
Subtotal	5,917	1,286	100.0	0.18	0.94
Grand total	70,661	11,117		2.19	11.22

↵^z Assumes statewide population of 32,231,000 (California Department of Finance 1996).
↵^y Assumes statewide street tree population of 6,300,000 (Bernhardt and Swiecki 1993).