Lower Rio Grande Valley Water Resources Conservation and Improvement Act of 1999

Lower Rio Grande Valley Water Resources Conservation and Improvement Act of 1999 - Directs the Secretary of the Interior, acting through the Commissioner of the Bureau of Reclamation and in cooperation with the Secretary of Agriculture, to undertake a program for improving the supply of water for the Texas counties of Cameron, Hidalgo, Starr, Willacy, Jim Hogg, Zapata, Webb, Maverick, Val Verde, Kinney, Terrell, Brewster, Presidio, Jeff Davis, Hudspeth, and El Paso through specified water transportation, conservation, and education activities. Makes a project ineligible for implementation unless: (1) the project plan shows an estimate of the amount of water that will be conserved; and (2) the design for the project includes a cost-of-project-to- water-developed ratio statement. Limits: (1) the non-Federal share of the costs of any such activity to 40 percent; and (2) payments by the State of Texas to 30 percent of such costs. Permits provision of the remainder of the non-Federal share to include in-kind contributions of goods and services.

Requires the Secretary, acting through the Commissioner and in cooperation with the Secretary of Agriculture, the counties, and other non-Federal entities, to: (1) assess alternative water supply options for the counties of Maverick, Kinney, Edwards, Val Verde, Terrell, Brewster, Presidio, Jeff Davis, Hudspeth, and El Paso for alleviating water supply shortages and project water demands; and (2) submit recommendations to Congress regarding such alternatives which shall emphasize water management actions that encourage the incorporation of prudent, responsible, and economically feasible water conservation measures. Requires the Secretary to assess the feasibility of wastewater reuse for irrigation and groundwater recharge and other nonpotable purposes. Limits the Federal share of the cost of any such activity to 50 percent. Prohibits the Secretary from carrying out any activity except under an agreement with a non- Federal entity that has legal authority under the laws of the State to obligate funds or provide in- kind services for such activity, under which the non-Federal entity is obligated to provide the non-Federal share of the cost of the activity.

Authorizes appropriations.