de·plete 
(dĭ-plēt)
(dĭ-plēt)tr.v. de·plet·ed, de·plet·ing, de·pletes
1. To consume or reduce to a very low amount; use up: drought that depleted the stores of grain.
2. To remove the contents or important elements of; empty out or exhaust: overfishing that depleted the lake of trout; farming practices that depleted the soil of nutrients.
[Latin dēplēre, dēplēt-, to empty : dē-, de- + plēre, to fill; see pelə-1 in the Appendix of Indo-European roots.]
de·pleta·ble adj.
Synonyms: deplete, drain, exhaust, sap1
These verbs mean to use up something important that is hard to replace. Deplete refers to gradually consuming something essential: Medical bills quickly depleted our savings. To drain is to draw down a resource or supply to a critical level: War often drains a nation's economy. Exhaust stresses depletion to a point of emptiness or uselessness: "The Depression had exhausted the capacity of private charities and state and local governments to cope with the needs of millions of unemployed Americans" (Patrick Maney).
Sap suggests a slow loss of something vital: "The [ivory] trade certainly sapped labor from farming and disrupted village life" (Eric Scigliano).
These verbs mean to use up something important that is hard to replace. Deplete refers to gradually consuming something essential: Medical bills quickly depleted our savings. To drain is to draw down a resource or supply to a critical level: War often drains a nation's economy. Exhaust stresses depletion to a point of emptiness or uselessness: "The Depression had exhausted the capacity of private charities and state and local governments to cope with the needs of millions of unemployed Americans" (Patrick Maney).
Sap suggests a slow loss of something vital: "The [ivory] trade certainly sapped labor from farming and disrupted village life" (Eric Scigliano).