Most altimetric datasets are designed for the deep oceans because land contaminates the return signal of the altimeter and radiometer.  To resolve these issues several projects have developed various algorithms tuned to coastal or inland waters that retrack and/or provide improved corrections. These projects provide their results as experimental datasets.

CTOH

CTOH (Center for Topographic studies on the Ocean and Hydrosphere) has a coastal altimetric dataset that is regionally corrected through the use of X-TRACK (http://ctoh.legos.obs-mip.fr/products/coastal-products).  X-TRACK is applied to TOPEX/Poseidon, Geosat Follow On, Jason-1, Envisat and OSTM/Jason-2. CTOH also contains time series for various rivers, lakes and wetlands water heights based from TOPEX/Poseidon, ERS-1&2, Geosat Follow On, Jason-1 and Envisat.
http://www.legos.obs-mip.fr/en/soa/hydrologie/hydroweb/

PEACHI

PEACHI (Prototype for Expertise on AltiKa for Coastal, Hydrology and Ice) is a project that generates coastal and hydrological altimetric datasets from SARAL's AltiKa SIGDR and SGDR.  It retracks the altimeter signal near land to remove aliasing.  
http://www.aviso.altimetry.fr/en/data/products/sea-surface-height-produc...

PISTACH

PISTACH (Prototype Innovant de Systèm de Traitement pour les Applications Côtières et l’Hydrologie) is a project that generates coastal and hydrological altimetric datasets from OSTM/Jason-2 IGDR.  It retracks the altimeter signal near land to remove aliasing.
http://www.aviso.altimetry.fr/en/data/products/sea-surface-height-products/global/coastal-and-hydrological-products.html

USDA

The United States Department of Agriculture’s Foreign Agricultural Service provides lake and river levels based on satellite altimeters, in conjunction with NASA and University of Maryland. 
http://www.pecad.fas.usda.gov/cropexplorer/global_reservoir/