Malaria and Schistosomiasis is the most prevalent water related vector born diseases, and theirrnimpact both in epidemic logical or monetary terms are enormous. These impacts are furtherrnintensified when irrigation project is instigated. They are endemic health problems, unless andrnotherwise in the area under in visitation.rnThe present study conducts an object in reassessment of the health damages incurred by householdsrndue to malaria and schistosomiasis in wonji cane plantation, and also over look the attributes ofrnirrigation exposure over and above with similar comparative area (Zeway) by using stat iatricalrnprobability of odds of a disease.rnHealth production function was adopted for valuing the damages from mosquito bite and circadianrninfestation, based on the theory of utility maximization behavior on aversion and illness. Thernpredicted probability o f observing illness in a household was used to estimate the damages inrnmonetary term s. Primary elate with a sample of 200 and 300 households were deployed from wonjirnbreezeway respectively. This enables as to derive treatment cost and wage loss pending from thernillness and to arrive at the total cost of illness. That is birr 288.65 and 83.03 for representativernhousehold and 57, 172 .50 and 16,439.94 birr per year for sampled households for malaria andrn'Schistosomiasis respectively, and irrigation peculiar health damages was estimated and becamern9.966.24 birr per year for both illnesses in a sampled household in chicane plantation.rnAccordingly health education through electronics media, wage income. educational attainment of thernhead of the household is the key determinant for aversion decision and malaria illness. Unexpectedly.rnthe role of bed net in malaria illness is positively related and in significant, butting indicate only onrnavers ion . The significant variables for schistosomiasis and defensive behavior are wage income.rnnon-wage income. illiteracy, knowing the symptoms, and unavailability o f potable water at householdrnlevel.rnThe health damage cost at household level and for representative samples are enormous. Therefore,rnth e study suggests that the government has to assess diseases impact not from epidemiology pointrnonly, but also to the economic cost aspect, which is crucial both at micro and macro levels. Moreover,rnthe government should Provide appropriate tap water at al l times, special health education at schoolrnlevel. adequate distribution of bed net that can be supported with follow-up. and compensation for thernopportunity cost they incurred when irrigation is implemented.